CN117016035A

CN117016035A - Method and apparatus for determining downlink control information reception priority in wireless communication system

Info

Publication number: CN117016035A
Application number: CN202280020652.4A
Authority: CN
Inventors: 张永禄; 林成穆; 池衡柱
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2021-03-12
Filing date: 2022-03-11
Publication date: 2023-11-07

Abstract

The present disclosure relates to 5G or 6G communication systems supporting higher data transmission rates. The present disclosure provides a method performed at a terminal in a wire communication system, the method comprising: receiving a Radio Resource Control (RRC) message including configuration information regarding a plurality of Search Spaces (SSs) from a base station; identifying a first set of control resources (CORESET) corresponding to a first SS having a lowest index of the plurality of SSs; identifying one or more SSs by excluding one or more first SSs associated with the first CORESET from the plurality of SSs; identifying at least one of the one or more SSs that is linked to one of the one or more first SSs; identifying a second CORESET corresponding to a second SS having a lowest index of the at least one SS; and monitoring a Physical Downlink Control Channel (PDCCH) in overlapping PDCCH monitoring occasions in the first CORESET and the second CORESET.

Description

Method and apparatus for determining downlink control information reception priority in wireless communication system

Technical Field

The present disclosure relates to operation of UEs and base stations in a wireless communication system. More particularly, the present disclosure relates to a method for determining a downlink control information reception priority in a wireless communication system, and an apparatus capable of performing the same.

Background

The 5G mobile communication technology defines a wide frequency band, thereby realizing a high transmission rate and a new service, and can be implemented not only in a "below 6Ghz" frequency band such as 3.5Ghz, but also in a "above 6Ghz" frequency band called millimeter wave (mmWave) example, including 28Ghz and 39Ghz. In addition, it has been considered to implement a 6G mobile communication technology (referred to as a super 5G system) in a terahertz band (e.g., 95Ghz to 3THz band) to achieve a transmission rate 50 times faster than that of a 5G mobile communication technology and an ultra low delay of up to one tenth of that of the 5G mobile communication technology.

At the beginning of the development of 5G mobile communication technology, the following have been standardized for supporting services and meeting performance requirements related to enhanced mobile broadband (emmbb), ultra-reliable low-latency communication (URLLC), and large-scale machine type communication (mctc): beamforming and massive MIMO to mitigate radio wave path loss in millimeter waves and increase radio wave transmission distance, support parameter sets (numerologies) for efficient use of millimeter wave resources and dynamic operation of slot formats (e.g., operating multiple subcarrier spacings); initial access technology supporting multi-beam transmission and broadband; definition and operation of BWP (bandwidth part); new channel coding methods such as LDPC (low density parity check) codes for large data transmission and polarity codes for highly reliable transmission of control information; l2 pretreatment; and network slicing for providing private networks dedicated to a particular service.

Currently, improvements and performance enhancements of the original 5G mobile communication technology are being discussed in view of services supported by the 5G mobile communication technology, and physical layer standardization has emerged for various types of technologies, such as V2X (vehicle to everything) technology, that facilitate automated driving vehicles to make driving decisions and enhance user convenience based on vehicle location and state information transmitted by the vehicle; NR-U (new radio unlicensed), which is intended to meet the requirements of performing system operations in the unlicensed band that meet various regulatory-related requirements; NR UE saves power; a non-terrestrial network (NTN), which is a type of UE satellite direct communication for providing coverage and positioning in areas where communication with a terrestrial network is not possible.

In addition, standardization of air interface architecture/protocols is also ongoing, such as industrial internet of things (IIoT) supporting new services through interworking and convergence with other industries; an IAB (integrated access and backhaul) of a node providing network service area extension by supporting a wireless backhaul link and an access link in an integrated manner; mobility enhancements including conditional handoff and DAPS (Dual active protocol stack) handoff; and two-step random access (two-step RACH of NR) for simplifying a random access procedure. In addition, system architecture/service standardization for the following items is also ongoing: a 5G baseline architecture (e.g., a service-based architecture or a service-based interface) that combines Network Function Virtualization (NFV) and Software Defined Network (SDN) technologies; and Mobile Edge Computing (MEC) for receiving a UE location based service.

With commercialization of the 5G mobile communication system, exponentially growing interconnection devices will be connected to the communication network, and thus enhancement of functions and performance of the 5G mobile communication system and integrated operation of the interconnection devices are required. For this reason, new studies involving augmented reality (XR) have been planned to effectively support AR (augmented reality), VR (virtual reality), MR (mixed reality), etc., to improve 5G performance and reduce complexity by using Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metacosmic service support, and unmanned aerial vehicle communication.

Furthermore, such development of 5G mobile communication systems will not only be based on developing new waveforms for 6G mobile communication technology, multi-antenna transmission technology such as full-dimensional MIMO (FD-MIMO), array antennas and large-scale antennas for improving terahertz band signal coverage, metamaterial-based lenses and antennas, terahertz band coverage using high-dimensional spatial multiplexing technology of OAM (orbital angular momentum) and RIS (reconfigurable intelligent super surface), but will also be based on developing full duplex technology for improving frequency efficiency of 6G mobile communication technology and improving system network, AI-based communication technology for implementing system optimization from design stage using satellites and AI (artificial intelligence) and internalizing end-to-end AI support functions, and next generation distributed computing technology for implementing services with ultra-high performance communication and computing resources to a complexity degree exceeding the UE operation capability limit.

The internet is a man-made connected network in which people generate and consume information. Today, the internet is evolving into internet of things (IoT) that can be exchanged and processed by distributed entities, such as objects, without human intervention. Internet of everything (IoE), which is a combination of internet of things technology and big data processing technology implemented by connection with a cloud server, has emerged. Since the implementation of the internet of things requires corresponding technical elements such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology" and "security technology", there is a recent study on sensor networks, machine-to-machine (M2M) communication, machine Type Communication (MTC), etc. The internet of things environments may provide intelligent Internet Technology (IT) services that create new value for human life by collecting and analyzing data generated between interconnected objects. Through the fusion and combination between the existing Information Technology (IT) and various industrial technologies, the internet of things can be applied to various fields including smart homes, smart buildings, smart cities, smart cars or interconnected cars, smart grids, healthcare, smart home appliances and advanced medical services.

Accordingly, various attempts have been made to apply 5G communication systems to IoT networks. For example, sensor networks, machine Type Communications (MTC), and machine-to-machine (M2M) communications, among other techniques, may be implemented by beamforming, MIMO, and array antennas. The application of the cloud radio access network (cloud RAN) as the big data processing technology described above can also be regarded as one example of the fusion of the 5G technology and the internet of things technology.

With the progress of the above-described wireless communication system, various services can be provided, and thus a scheme for efficiently providing these services is required.

Disclosure of Invention

[ technical problem ]

The present disclosure may provide an apparatus and method capable of efficiently providing a service in a mobile communication system.

[ solution to problem ]

The technical subject matter proposed by the present disclosure may not be limited to the above technical subject matter, and other technical subject matter not mentioned may be clearly understood by those skilled in the art to which the present disclosure pertains from the following description.

To solve the above problems, the present disclosure may provide a method performed by a terminal in a wireless communication system, the method including: receiving a Radio Resource Control (RRC) message including configuration information regarding a plurality of Search Spaces (SSs) from a base station; identifying a first set of control resources (CORESET) corresponding to a first SS having a lowest index of the plurality of SSs; identifying one or more SSs by excluding one or more first SSs associated with the first CORESET from the plurality of SSs; identifying at least one of the one or more SSs that is linked to one of the one or more first SSs; identifying a second CORESET corresponding to a second SS having a lowest index of the at least one SS; and monitoring a Physical Downlink Control Channel (PDCCH) in overlapping PDCCH monitoring occasions in the first CORESET and the second CORESET.

For processing control signals in a wireless communication system, a method comprises: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting the second control signal generated based on the processing to the base station.

According to the embodiments of the present disclosure, an apparatus and method capable of efficiently providing a service in a mobile communication system may be provided.

The advantageous effects obtainable by the present disclosure may not be limited to the above-described effects, and other effects not mentioned may be clearly understood by those skilled in the art to which the present disclosure pertains from the following description.

Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used in this patent document: the terms "include" and "comprise" and derivatives thereof mean inclusion without limitation; the term "or" is inclusive, meaning "and/or"; the phrases "associated with" and derivatives thereof mean including, included within, interconnected with, containing, contained within, connected to or coupled with, communicable with, cooperating with, interleaving, juxtaposing, approaching, combining with or combining with, owning, possession of the property, etc.; and the term "controller" refers to any device, system, or portion thereof that controls at least one operation, which may be implemented in hardware, firmware, or software, or a specific combination of at least two thereof. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely.

Furthermore, the various functions described below may be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and implemented in a computer readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer readable medium" includes any type of medium capable of being accessed by a computer, such as Read Only Memory (ROM), random Access Memory (RAM), a hard disk drive, a Compact Disc (CD), a Digital Video Disc (DVD), or any other type of memory. "non-transitory" computer-readable media do not include wired, wireless, optical, or other communication links that transmit transitory electrical signals or other signals. Non-transitory computer readable media include media that can permanently store data and media that can store and later overwrite data, such as rewritable optical disks or removable storage devices.

Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

Advantageous effects of the present disclosure

There is an improvement in determining downlink control information reception priority in a wireless communication system.

Drawings

The foregoing and other aspects, features, and advantages of certain embodiments of the disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings in which:

fig. 1 illustrates a basic structure of a time-frequency domain in a wireless communication system according to one embodiment of the present disclosure;

fig. 2 illustrates frame, subframe, and slot structures in a wireless communication system according to one embodiment of the present disclosure;

fig. 3 illustrates an example of configuring a bandwidth portion in a wireless communication system according to one embodiment of the present disclosure;

fig. 4 illustrates an example of configuring a control region of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure;

fig. 5A illustrates a structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure;

Fig. 5B illustrates a case where a UE can have a plurality of PDCCH monitoring occasions within a slot through Span (Span) in a wireless communication system according to one embodiment of the present disclosure;

fig. 6 illustrates an example of DRX operation in a wireless communication system according to one embodiment of the present disclosure;

fig. 7 illustrates an example of base station beam allocation according to TCI state configuration in a wireless communication system according to one embodiment of the present disclosure;

fig. 8 illustrates an example of a TCI state allocation method of a PDCCH in a wireless communication system according to one embodiment of the present disclosure;

fig. 9 illustrates a TCI indication MAC CE signaling structure for PDCCH DMRS in a wireless communication system according to one embodiment of the present disclosure;

fig. 10 illustrates an example of a beam configuration of a control resource set and a search space in a wireless communication system according to one embodiment of the present disclosure;

fig. 11 is a method for a base station and a UE to transmit and receive data in consideration of a downlink data channel and rate matching resources in a wireless communication system according to an embodiment of the present disclosure;

fig. 12 illustrates a method for a UE to select a set of receivable control resources in consideration of priority when receiving a downlink control channel in a wireless communication system according to one embodiment of the present disclosure;

Fig. 13 illustrates an example of an aperiodic CSI reporting method according to one embodiment of the present disclosure;

fig. 14 illustrates an example of frequency axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the disclosure;

fig. 15 illustrates an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the disclosure;

fig. 16 illustrates an example of time axis resource allocation according to subcarrier spacing of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure;

fig. 17 illustrates an example of a B-type repeated PUSCH transmission in a wireless communication system according to one embodiment of the present disclosure;

fig. 18 illustrates a radio protocol structure of a base station and a UE in a single cell, carrier aggregation, and dual connectivity case in a wireless communication system according to one embodiment of the present disclosure;

fig. 19 illustrates an example of antenna port configuration and resource allocation for cooperative communication in a wireless communication system in accordance with one embodiment of the present disclosure;

fig. 20 illustrates a configuration example of Downlink Control Information (DCI) for cooperative communication in a wireless communication system according to one embodiment of the present disclosure;

fig. 21 illustrates a method of determining priority when receiving duplicate PDCCH transmissions according to one embodiment of the present disclosure;

Fig. 22A illustrates UE and base station operation with respect to a method of determining priority when receiving duplicate PDCCH transmissions, according to one embodiment of the present disclosure;

fig. 22B illustrates UE and base station operation with respect to a method of determining priority when receiving duplicate PDCCH transmissions, according to one embodiment of the present disclosure;

fig. 23A illustrates UE and base station operation with respect to a method of determining priority when receiving duplicate PDCCH transmissions, according to another embodiment of the present disclosure;

fig. 23B illustrates UE and base station operation with respect to a method of determining priority when receiving duplicate PDCCH transmissions, according to another embodiment of the present disclosure;

fig. 24 illustrates a structure of a UE in a wireless communication system according to one embodiment of the present disclosure; and is also provided with

Fig. 25 illustrates a structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

Detailed Description

Figures 1 through 25, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will appreciate that the principles of the present disclosure may be implemented in any suitably arranged system or device.

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

In describing embodiments of the present disclosure, a description of technical contents that are well known in the art and are not directly associated with the present disclosure will be omitted. The unnecessary description is omitted so as not to obscure the main idea of the present disclosure, and so as to more clearly convey the main idea.

For the same reason, some elements may be enlarged, omitted, or schematically shown in the drawings. Furthermore, the size of each element does not fully reflect the actual size. In the drawings, identical or corresponding elements are indicated by identical reference numerals.

The advantages and features of the present disclosure, as well as embodiments thereof, will become apparent from the following detailed description of embodiments when taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments set forth below, but may be embodied in various forms. The following examples are provided solely to fully disclose the present disclosure and to inform those of ordinary skill in the art of the scope of the present disclosure and the present disclosure is limited only by the scope of the appended claims. Throughout the specification, the same or similar reference numerals denote the same or similar elements. Further, in describing the present disclosure, when it is determined that a detailed description of known functions or configurations incorporated within the present disclosure may unnecessarily obscure the subject matter of the present disclosure, the detailed description will be omitted. The terms to be described below are terms defined in consideration of functions in the present disclosure, and may be different according to users, user intention, or habits. Accordingly, the definition of the terms should be based on the contents of the entire specification.

In the following description, a base station is an entity that allocates resources for a terminal, and may be at least one of a eNode B, an eNode B, a node B, a Base Station (BS), a radio access unit, a base station controller, or a node on a network. A terminal may include a User Equipment (UE), a Mobile Station (MS), a cellular phone, a smart phone, a computer, and a multimedia system capable of performing a communication function. In the present disclosure, "Downlink (DL)" refers to a radio link via which a base station transmits signals to a terminal, and "Uplink (UL)" refers to a radio link via which a terminal transmits signals to a base station. Furthermore, in the following description, an LTE or LTE-a system may be described by way of example, but embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. Examples of such communication systems may include fifth generation mobile communication technologies (5G, new air interface, and NR) developed outside of LTE-a, and in the following description, "5G" may be a concept covering existing LTE, LTE-a, or other similar services. Moreover, based on a determination by those skilled in the art, embodiments of the present disclosure may also be applied to other communication systems with certain modifications without departing significantly from the scope of the present disclosure.

In this document, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block or blocks. These computer program instructions may also be stored in a computer-usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

Furthermore, each block in the flowchart may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

As used herein, "unit" refers to a software element or a hardware element, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), that performs a predetermined function. However, "unit" is not always meant to be limited to software or hardware. A "unit" may be interpreted as being located in an addressable storage medium or executing one or more processors. Thus, a "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and parameters. Elements and functions provided by a "unit" may be combined into a fewer number of elements or "units" or may be divided into a greater number of elements or "units". Furthermore, these elements and "units" may also be implemented to render one or more CPUs within a device or secure multimedia card. Further, a "unit" in an embodiment may include one or more processors.

Wireless communication systems have evolved from providing voice-oriented initial services to a broadband wireless communication system that provides high-speed high quality packet data services such as high-speed packet access (HSPA) of 3GPP, long Term Evolution (LTE) or evolved universal terrestrial radio access (E-UTRA), LTE-advanced (LTE-a), LTE-Pro, high-speed packet data (HRPD) in 3GPP2, ultra Mobile Broadband (UMB), and communication standards such as IEEE 802.16E.

In an LTE system, which is a representative example of a broadband wireless communication system, an Orthogonal Frequency Division Multiplexing (OFDM) scheme is employed in a downlink (UL) and a single carrier frequency division multiple access (scdma) scheme is employed in an Uplink (UL). The uplink refers to a radio link via which a User Equipment (UE) or a Mobile Station (MS) transmits data or control signals to a Base Station (BS) (eNode B or base station), and the downlink refers to a radio link via which a base station transmits data or control signals to the UE. The above-described multiple access method establishes orthogonality by allocating and operating time-frequency resources to which data or control information about each user is transmitted such that the data and control information of each user to be distinguished do not overlap each other.

The 5G communication system is a communication system after LTE, and can support services that simultaneously satisfy various requirements, thereby freely reflecting various requirements of users and service providers. Services considered for 5G communication systems include enhanced mobile broadband (emmbb), mass machine type communication (mctc), and Ultra Reliable Low Latency Communication (URLLC).

The eMBB is intended to provide a higher data transmission rate than that supported by existing LTE, LTE-a or LTE-Pro. For example, in a 5G communication system, from the perspective of one base station, an eMBB should be able to provide a peak data rate of 20Gbps in the downlink and 10Gbps in the UL. Furthermore, the 5G communication system may enable the UE user perceived data rate to be increased while providing a peak data rate. To meet these requirements, improvements in various transmission/reception techniques are needed, including further improved Multiple Input Multiple Output (MIMO) transmission techniques. Further, although LTE transmits signals using a transmission bandwidth of up to 20MHz in a 2GHz band, a 5G communication system can satisfy a data rate required for the 5G communication system by using a frequency bandwidth wider than 20MHz in a 3GHz to 6GHz or higher band.

Meanwhile, mctc is also considered to support application services such as internet of things (IoT) in 5G communication systems. In order to efficiently provide the internet of things, mctc needs to support large-scale UE access in a cell, improve UE coverage, prolong battery life, reduce UE cost, and the like. Since the internet of things is connected to various sensors and various devices to provide communication functions, it may be able to support a large number of UEs (e.g., 1,000,000 UEs/km 2) within a cell. Furthermore, since a UE supporting mctc is most likely to be located in a shadow area within a cell that is not covered due to the nature of the service, such as a building basement, it may be desirable to have a wider coverage range than other services provided by a 5G communication system. UEs supporting mctc may consist of low cost UEs and may require very long battery life, e.g., 10 years to 15 years, due to the difficulty in frequently replacing the battery of the UE.

Finally, URLLC is a cellular-based wireless communication service for specific purposes (mission critical). For example, services for remotely controlling robots or machines, industrial automation, unmanned aerial vehicles, remote healthcare, emergency alerts, etc. may be considered. Thus, the communication provided by URLLC may provide very low latency and very high reliability. For example, a service supporting URLLC may meet a null delay of less than 0.5 ms while meeting the requirements for packet error rates of 10-5 or less. Thus, for services supporting URLLC, a 5G system may provide smaller Transmission Time Intervals (TTIs) than other services, while at the same time may need to meet the design requirements for allocation of wide resources within the frequency band to ensure the reliability of the communication link.

Three 5G services, namely emmbb, URLLC, and mctc, can be multiplexed and transmitted in one system. In this case, different transmission/reception techniques and transmission/reception parameters may be used between services to satisfy different requirements of each service. Of course, 5G is not limited to the above three services.

[ NR time-frequency resource ]

Hereinafter, a frame structure of the 5G system will be described in more detail with reference to the accompanying drawings.

Fig. 1 illustrates a basic structure of a time-frequency domain, which is a radio resource domain for transmitting data or control channels in a 5G system.

The horizontal and vertical axes in fig. 1 represent the time and frequency domains, respectively. The basic unit of resources in the time and frequency domains is a Resource Element (RE) 101, which may be defined as one Orthogonal Frequency Division Multiplexing (OFDM) symbol 102 on the time axis, and may be defined as one subcarrier 103 on the frequency axis. One Resource Block (RB) 104 in the frequency domain may be composed ofAnd each (e.g., 12) consecutive REs.

Fig. 2 illustrates a frame, subframe, and slot structure of a wireless communication system according to one embodiment of the present disclosure.

An example of a frame 200, a subframe 201, and a slot 202 is shown in fig. 2. One frame 200 may be defined as 10ms. One subframe 201 may be defined as 1ms, and accordingly, one frame 200 may include a total of 10 subframes 201. One slot 202 and 203 may be defined as 14 OFDM symbols (i.e., the number of symbols per slot). One subframe 201 may include one or more slots 202 and 203, and the number of slots 202 and 203 of each subframe 201 may vary according to the set values of subcarrier spacing, mu 204 and 205. In the example of fig. 2, the cases of μ=0 204 and μ=1 205 are illustrated as subcarrier spacing settings. When μ=0 204, one subframe 201 may include one slot 202, and when μ=1, 205, one subframe 201 may include two slots 203. That is, the number of slots per subframe is +_ according to the subcarrier spacing set value μ >May be different and accordingly, the number of slots per subframe +.>May be different. According to the +.about.of the per subcarrier spacing set value μ>And->May be defined as in table 1 below.

TABLE 1

Bandwidth portion (BWP)

The bandwidth part (BWP) configuration in the 5G communication system will be described in detail with reference to the accompanying drawings.

Fig. 3 illustrates an example of a configuration of a bandwidth part (BWP) in a wireless communication system according to one embodiment of the present disclosure.

Fig. 3 shows an example in which a UE bandwidth 300 is configured into two bandwidth parts, namely a bandwidth part #1 (BWP # 1) 301 and a bandwidth part #2 (BWP # 2) 302. The base station may configure one or more bandwidth parts for the UE and may configure information as shown in the following table 2 for each bandwidth part.

TABLE 2

Not limited to the above example, various parameters related to the bandwidth part may be configured into the UE in addition to the above configuration information. The above information may be transmitted from the base station to the UE through upper layer signaling, such as Radio Resource Control (RRC) signaling. At least one of the one or more configured bandwidth portions may be activated. Whether the configured bandwidth part is activated may be semi-statically transmitted from the base station to the UE through RRC signaling or may be dynamically transmitted through Downlink Control Information (DCI).

According to some embodiments, the UE may receive an initial BWP prior to a Radio Resource Control (RRC) connection in order to perform initial access configured from the BS through a Master Information Block (MIB). More specifically, in order to receive system information (remaining system information; RMSI or system information block 1; may correspond to SIB 1) required for initial access through the MIB in the initial access step, the UE may receive configuration information about a control region (control resource set, CORESET) through which the PDCCH and configuration information about a search space may be transmitted. The control region and the search space configured via the MIB may be regarded as an identity Identifier (ID) 0, respectively. The base station may inform the UE of configuration information of the control region #0, such as frequency allocation information, time allocation information, and parameter set (numerology), through the MIB. In addition, the base station may inform the UE of configuration information on the monitoring period and timing of the control region #0, i.e., configuration information on the search space #0, through the MIB. The UE may consider the frequency domain of the control region #0 configured to be obtained through the MIB as an initial bandwidth portion of the initial access. In this case, the Identity (ID) of the initial bandwidth portion may be considered as 0.

The bandwidth part configuration supported by the above 5G may be used for various purposes.

According to some embodiments, when the bandwidth supported by the UE is less than the system bandwidth, the bandwidth supported by the UE may be supported by configuring for the bandwidth portion. For example, the base station configures the frequency location (configuration information 2) of the bandwidth part to the UE so that the UE can transmit and receive data at a specific frequency location within the system bandwidth.

Further, according to some embodiments, to support different parameter sets (numerologies), a base station may configure multiple bandwidth parts to a UE. For example, to support data transmission and reception for any UE using 15kHz subcarrier spacing and 30kHz subcarrier spacing, the two bandwidth portions may be configured to use 15kHz and 30kHz subcarrier spacing, respectively. The different bandwidth parts may be frequency division multiplexed, and when data is transmitted/received in a specific subcarrier space, a bandwidth part configured for the corresponding subcarrier space may be activated.

Further, according to some embodiments, to reduce power consumption of the UE, the base station may configure bandwidth portions having different sizes of bandwidths to the UE. For example, when a UE supports a very large bandwidth, e.g., a bandwidth of 100MHz, and always transmits and receives data using the corresponding bandwidth, very large power consumption may occur. In particular, in terms of power consumption, it may be very inefficient for a UE to monitor the downlink control channel for an unnecessarily large bandwidth of 100MHz without traffic. To reduce the power consumption of the UE, the base station may configure a relatively narrow bandwidth portion, e.g., a 20MHz bandwidth portion, to the UE. Without traffic, the UE may monitor in a bandwidth portion of 20MHz, and when generating data, the UE may transmit/receive data through the bandwidth portion of 100MHz according to an instruction of the base station.

In the above method of configuring a bandwidth part, the UE may receive configuration information about the initial bandwidth part through a Master Information Block (MIB) in an initial access step before RRC connection. More specifically, the UE may receive a control region (control resource set CORESET) configured for a downlink control channel (PBCH) from a MIB of the Physical Broadcast Channel (PBCH) over which Downlink Control Information (DCI) scheduling System Information Blocks (SIBs) may be transmitted. The bandwidth of the MIB-configured control region may be regarded as an initial bandwidth portion, and through the configured initial bandwidth portion, the UE may receive a Physical Downlink Shared Channel (PDSCH) via which SIBs are transmitted. In addition to the purpose of receiving SIBs, the initial bandwidth portion may also be used for Other System Information (OSI), paging, and random access.

[ Bandwidth portion (BWP) Change ]

When configuring one or more bandwidth parts for a UE, a base station may use a bandwidth part indicator field in DCI to instruct the UE to alter (or switch, transition) the bandwidth part. For example, when the bandwidth part of the currently activated UE in fig. 3 is bandwidth part #1 301, the base station may indicate to the UE that bandwidth part #2 is a bandwidth part indicator in the DCI, and the UE may change the bandwidth part to bandwidth part #2 302 indicated by the bandwidth part indicator in the received DCI.

As described above, since the DCI-based bandwidth part change may be indicated by DCI scheduling PDSCH or PUSCH, when the UE receives a bandwidth part change request, the UE may be able to receive or transmit PDSCH or PUSCH scheduled by the corresponding DCI in the changed bandwidth part without encountering difficulty. To this end, the standard specifies the delay Time (TBWP) requirements required when the bandwidth part is changed, and may be defined, for example, as shown in table 3 below.

TABLE 3

Depending on the functionality of the UE, the requirement of the bandwidth part change delay time may support type 1 or type 2. The UE may report supportable bandwidth part delay time types to the base station.

When the UE receives the DCI including the bandwidth part change indicator in the slot n according to the above-described bandwidth part change delay time requirement, the UE may complete the operation of changing the bandwidth part to the new bandwidth part indicated by the bandwidth part change indicator at a point of time not later than the slot n+tbwp and transmit and receive the data channel scheduled by the DCI in the changed new bandwidth part. When the base station intends to schedule the data channel using the new bandwidth part, the time domain resource allocation of the data channel may be determined in consideration of the bandwidth part variation delay Time (TBWP) of the UE. That is, when the base station schedules a data channel using a new bandwidth part, in the method of determining time domain resource allocation of the data channel, the base station may schedule a corresponding data channel after the bandwidth part changes a delay time. Accordingly, the UE may not expect the DCI indicating the bandwidth part change to indicate that the slot offset (K0 or K2) value is less than the bandwidth part change delay Time (TBWP).

If the UE receives DCI (e.g., DCI format 1_1 or 0_1) indicating a change in a bandwidth part, the UE does not perform any transmission or reception for a time interval from a third symbol of a slot where a PDCCH including the corresponding DCI is received to a slot start point indicated by a slot offset (K0 or K2) value indicated by a time domain resource allocation indicator field in the corresponding DCI. For example, if the UE receives DCI indicating a change in a bandwidth part in the slot n and the slot offset value indicated by the DCI is K, the UE may not perform any transmission or reception during a previous symbol of the slot n+k (a last symbol of the instant n+k-1) from a third symbol of the slot n.

[ SS/PBCH Block ]

Next, a Synchronization Signal (SS)/PBCH block in 5G will be described.

The SS/PBCH block may refer to a physical layer channel block composed of a primary SS (PSS), a Secondary SS (SSs), and a PBCH. Specifically, the following is shown.

-PSS: a signal used as a reference for downlink time/frequency synchronization and provides some information about the cell ID.

SSS: serves as a reference for downlink time/frequency synchronization and provides remaining cell ID information not provided by the PSS. In addition, SSS may be used as a reference signal for PBCH demodulation.

-PBCH: providing necessary system information required for the UE to transmit and receive the data channel and the control channel. The necessary system information may include control information related to a search space indicating radio resource mapping information of a control channel, scheduling control information of a separate data channel for transmitting the system information, and the like.

-SS/PBCH block: SS/PBCH blocks consisting of a combination of PSS, SSS and PBCH. One or more SS/PBCH blocks may be transmitted within 5ms and each transmitted SS/PBCH block may be distinguished by an index.

The UE may detect PSS and SSS in the initial access phase and decode the PBCH. The UE may obtain the MIB from the PBCH and may receive a control resource set (CORESET) #0 (which may correspond to a control resource set with a control resource set index of 0) configured therefrom. Assuming that the selected SS/PBCH module and a demodulation reference signal (DMRS) transmitted from the control resource set #0 are quasi co-located (QCL), the UE may perform monitoring on the control resource set #0. The UE may receive system information as downlink control information transmitted from the control resource set #0. The UE may acquire Random Access Channel (RACH) related configuration information required for initial access from the received system information. The UE may transmit a Physical RACH (PRACH) to the base station in consideration of the selected SS/PBCH index, and the base station receiving the PRACH may collect information about the SS/PBCH block index selected by the UE. The base station may identify the block that the UE selects from each SS/PBCH block and monitor the control resource set #0 associated therewith.

[ PDCCH: related to DCI ]

Downlink Control Information (DCI) in the 5G system will be described in detail.

In the 5G system, scheduling information on uplink data (or physical uplink shared channel PUSCH) or downlink data (or physical downlink shared channel PDSCH) may be transmitted from the base station to the UE through DCI. Ue may monitor the backoff of the DCI format, and the non-backoff PUSCH or PDSCH of the DCI format. The fallback DCI format may consist of a fixed field predefined between the base station and the UE, and the non-fallback DCI format may include a configurable field.

The DCI may be transmitted through a Physical Downlink Control Channel (PDCCH) after a channel coding and modulation procedure. A Cyclic Redundancy Check (CRC) is appended to the DCI message payload and the CRC may be scrambled by a Radio Network Temporary Identifier (RNTI) corresponding to the UE identity. Different RNTIs may be used according to the purpose of the DCI message, e.g., UE-specific data transmission, power control command, or random access response. That is, the RNTI is not explicitly transmitted, but is included in the CRC calculation process. Upon receiving the DCI message transmitted through the PDCCH, the UE recognizes the CRC using the allocated RNTI, and if the CRC recognition result is correct, the UE may determine that the message has been transmitted to the UE.

For example, DCI for PDSCH of scheduling System Information (SI) may be scrambled using SI-RNTI. DCI for PDSCH of a scheduling Random Access Response (RAR) message may be scrambled using RA-RNTI. The DCI of the PDSCH scheduling the paging message may be scrambled using the P-RNTI. The DCI informing the Slot Format Indicator (SFI) may be scrambled using the SFI-RNTI. The DCI informing of Transmit Power Control (TPC) may be scrambled using TPC-RNTI. The DCI scheduling the UE-specific PDSCH or PUSCH may be scrambled using a cell RNTI (C-RNTI).

The DCI format 0_0 may be used as a fallback DCI for scheduling PDSCH, and in this case, the CRC may be scrambled using the C-RNTI. DCI format 0_0 that scrambles the CRC using the C-RNTI may include information in table 4 below, for example.

TABLE 4

The DCI format 0_1 may be used as non-fallback DCI for scheduling PDSCH, and in this case, CRC may be scrambled using C-RNTI. DCI format 0_1 for scrambling a CRC using a C-RNTI may include information in table 5 below, for example.

TABLE 5

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The DCI format 1_0 may be used as a fallback DCI for scheduling PDSCH, and in this case, the CRC may be scrambled using the C-RNTI. DCI format 1_0 that scrambles the CRC using the C-RNTI may include information in table 6 below, for example.

TABLE 6

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DCI format 1_1 may be used as non-fallback DCI for scheduling PDSCH, and in this case, CRC may be scrambled using C-RNTI. DCI format 1_1 for scrambling a CRC using a C-RNTI may include information in the following table 7, for example.

TABLE 7

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

The downlink control channel in the 5G communication system will be described in more detail with reference to the accompanying drawings.

Fig. 4 illustrates an example of a control resource set (CORESET) for transmitting a downlink control channel in a 5G wireless communication system. Fig. 4 shows an example in which a UE bandwidth part 410 is configured on a frequency axis, and two control sets, i.e., a resource set #1 401 and a control resource set #2 402 are configured in one slot 420 on a time axis. The control resource sets 401 and 402 may be configured in the frequency domain as specific frequency resources 403 within the entire UE bandwidth part 410. The control resource sets 401 and 402 may be configured as one or more OFDM symbols on the time axis, and this may be defined as a control resource set duration 404. Referring to the example shown in fig. 4, control resource set #1 401 is configured as a control resource set duration of 2 symbols, and control resource set #2 402 is configured as a control resource set duration of 1 symbol.

The control resource set in 5G described above may be configured by the base station to the UE through upper layer signaling, e.g., system information, master Information Block (MIB), and Radio Resource Control (RRC) signaling. The allocation of the control resource set to the UE means providing information such as a control resource set identifier (identity), a frequency location of the control resource set, a symbol length of the control resource set, and the like. For example, information such as the following table 8 may be included.

TABLE 8

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In table 8, TCI-statepdcch (abbreviated Transmission Configuration Indication (TCI) status) configuration information may include information about quasi co-location (QCL) relationship of one or more Synchronization Signal (SS)/Physical Broadcast Channel (PBCH) block indexes and DMRS transmitted in a corresponding control resource set or CSI-RS (channel state information reference signal) index.

Fig. 5A is a diagram illustrating an example of basic time and frequency resource units constituting a downlink control channel that can be used in fig. 5G. According to fig. 5A, the time and frequency resource basic units constituting the control channel may be referred to as Resource Element Groups (REGs) 503, and the REGs 503 may be defined as 1 OFDM symbol 501 on the time axis and 1 Physical Resource Block (PRB) 502, i.e., 12 subcarriers, on the frequency axis. The base station may configure the downlink control channel allocation unit by concatenating REGs 503.

As shown in fig. 5A, when a basic unit of allocating a downlink control channel in 5G is referred to as a Control Channel Element (CCE) 504, one CCE 504 may be composed of a plurality of REGs 503. Describing REG 503 shown in fig. 5A as an example, REG 503 may consist of 12 REs, and if 1 CCE 504 consists of 6 REGs 503, 1 CCE 504 may consist of 72 REs. When configuring a set of downlink control resources, a corresponding region may be composed of a plurality of CCEs 504, and a particular downlink control channel is mapped to one or more CCEs 504 and transmitted according to an Aggregation Level (AL) within the control region. CCEs 504 in the control resource set are divided by numbers, and in this case, the numbers of CCEs 504 may be allocated according to a logical mapping method.

The basic elements of the downlink control channel, namely REGs 503 shown in fig. 5A, may include REs to which DCI is mapped and regions to which demodulation reference signals (DMRS) 505, which are Reference Signals (RSs) for decoding the REs, are mapped. As shown in fig. 5A, 3 DMRSs 505 may be transmitted within one REG 503. The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 according to an Aggregation Level (AL), and link adaptation of a downlink control channel may be implemented using different numbers of CCEs. For example, when al=l, one downlink control channel may be transmitted through L CCEs. The UE needs to detect the signal without knowing information about the downlink control channel, and for blind decoding, a search space is defined indicating a set of CCEs. Since the search space is a downlink control channel candidate set composed of CCEs that a UE may attempt to decode at a given aggregation level, and a bundle of 1, 2, 4, 8, or 16 CCEs is composed of multiple aggregation levels, the UE may have multiple search spaces. The set of search spaces may be defined as a set of search spaces in all configured aggregation levels.

The search space may be divided into a common search space and a UE-specific search space. The UE of a specific group or all UEs may investigate the common search space of the PDCCH to receive cell common control information, such as dynamic scheduling of system information or paging messages. For example, the UE may receive PDSCH scheduling allocation information regarding SIB transmission, including operator information of the cell, by investigating a common search space of the PDCCH. In the case of a common search space, since a UE of a specific group or all UEs may receive a PDCCH, the common search space may be defined as a set of committed CCEs. Scheduling allocation information on a UE-specific PDSCH or PUSCH may be received by investigating a UE-specific search space of a PDCCH. The UE-specific search space may be specifically defined for the UE as a function of the identity of the UE and various system parameters.

In 5G, search space parameters of the PDCCH may be configured from the base station to the UE through upper layer signaling (e.g., SIB, MIB, and RRC signaling). For example, the base station may configure the UE with the number of PDCCH candidates in each aggregation level L, a monitoring period for a search space, a monitoring occasion in a symbol unit in a slot for a search space, a search space type (common search space or UE-specific search space), a combination of DCI format and RNTI to be monitored in a corresponding search space, a control resource set index for monitoring a search space, and the like. For example, the following information may be included as shown in table 9 below.

TABLE 9

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Based on the configuration information, the base station may configure one or more search space sets to the UE. According to some embodiments, a base station may configure a search space set #1 and a search space set #2 to a UE, wherein in search space set 1, the UE may be configured to monitor DCI format a scrambled using an X-RNTI in a common search space, and in search space set 2, the UE may be configured to monitor DCI format B scrambled using a Y-RNTI in a UE-specific search space.

Depending on the configuration information, there may be one or more sets of search spaces in a common search space or a UE-specific search space. For example, search space set #1 and search space set #2 may be configured as a common search space, and search space set #3 and search space set #4 may be configured as UE-specific search spaces.

In the common search space, the following DCI format and RNTI combinations may be monitored. Of course, the present disclosure is not limited to the following examples:

-DCI format 0_0/1_0, scrambling CRC using C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI;

-DCI format 2_0, scrambling the CRC using SFI-RNTI;

-DCI format 2_1, scrambling CRC using INT-RNTI;

-DCI format 2_2, scrambling CRC using TPC-PUSCH-RNTI, TPC-PUCCH-RNTI; and

DCI format 2_3, CRC is scrambled using TPC-SRS-RNTI.

In the UE-specific search space, the following DCI format and RNTI combinations may be monitored. Of course, the present disclosure is not limited to the following examples:

-DCI format 0_0/1_0, scrambling CRC using C-RNTI, CS-RNTI, TC-RNTI; and is also provided with

DCI format 1_0/1_1, CRC is scrambled using C-RNTI, CS-RNTI, TC-RNTI.

The specified RNTI may follow the following definition and purpose:

-C-RNTI (cell RNTI): UE-specific PDSCH scheduling purposes;

-TC-RNTI (temporary cell RNTI): UE-specific PDSCH scheduling purposes;

CS-RNTI (configured scheduling RNTI): semi-statically configured UE-specific PDSCH scheduling purposes;

RA-RNTI (random access RNTI): the method is used for PDSCH scheduling purposes in a random access stage;

-P-RNTI (paging RNTI): PDSCH scheduling purpose of transmitting pages;

SI-RNTI (system information RNTI): PDSCH scheduling purpose of transmitting system information;

-INT-RNTI (interrupt RNTI): for indicating whether PDSCH is punctured;

TPC-PUSCH-RNTI (transmit power control for PUSCH RNTI): a power control command for indicating PUSCH;

TPC-PUCCH-RNTI (transmit power control for PUCCH RNTI): a power control command for indicating PUCCH; and is also provided with

TPC-SRS-RNTI (transmit power control for SRS RNTI): a power control command for indicating SRS.

The DCI formats specified above may follow the definitions in table 10 below, for example.

TABLE 10

In 5G, the search space of aggregation level L in control resource set p and search space set s may be expressed as the following equation 1.

[ equation 1]

-L: aggregation level

-n _CI : carrier index

-N _CCE,p : total number of CCEs present in control region p

-n ^μ _s,f : time slot index

-M ^(L) _p.s.max : number of PDCCH candidates for aggregation level L

-m _snCI ＝0,...,M ^(L) _p.s.max -1: PDCCH candidate index of aggregation level L

-i＝0,...,L-1

-Y _p，-1 n _RNTI ≠0，A ₀ ＝39827,A ₁ ＝39829,A ₂ ＝39839,D＝65537

-n _RNTI : UE identity

At the publicIn the case of a co-search space,the value may correspond to 0.

The value may correspond to a value that varies according to the identity of the UE (C-RNTI or ID configured by the base station for the UE) and the time index in the UE-specific search space. />

In 5G, since multiple search space sets may be configured with different parameters (e.g., parameters in table 9), the search space set monitored by the UE at each point in time may vary. For example, if search space set #1 is configured with X slot periods and search space set #2 is configured with Y slot periods, and X and Y are different, the UE may monitor both search space set #1 and search space set #2 in a specific slot and may monitor search space set #1 and search space set #2 in another specific slot.

[ PDCCH: span ]

In case of having a plurality of PDCCH monitoring occasions within one slot, the UE may perform UE capability reporting for each subcarrier interval, and in this case, the concept of span may be used. The span refers to consecutive symbols for the UE to monitor the PDCCH in a slot, each PDCCH monitoring occasion being within one span. The span may be denoted as (X, Y), where X refers to the minimum number of symbols that can be separated between the first symbol of two consecutive spans, and Y refers to the number of consecutive symbols that can monitor PDCCH within one span. In this case, the UE may monitor the PDCCH in Y symbols from the first symbol of the span in the span.

Fig. 5B illustrates a case in which a UE may have a plurality of PDCCH monitoring occasions within a slot by span in a wireless communication system. The spans may be (X, Y) = (7, 3), (4, 3), and (2, 2), and these three cases are illustrated in fig. 5B as 5a-00, 5a-05, and 5a-10. For example, 5a-00 represents the case where there are two spans in a slot that may be represented as (7, 3). The interval between the first symbol of two spans is denoted as x=7, and PDCCH monitoring occasions may exist within a total of y=3 symbols of the first symbol of each span, indicating that search spaces 1 and 2 exist within y=3 symbols, respectively. As another example, in 5a-05, i.e. where there are three spans within a slot that can be represented as (4, 3) countermeasures in total, and the interval between the second and third spans is illustrated as being separated by more than x=4X' =5 symbols.

[ PDCCH: UE capability report ]

The slot positions where the above common search space and the UE-specific search space are located are represented by monitoringsymbolswitnesslot parameters of table 9, and symbol positions in the slots are indicated by bitmaps by monitoringsymbolswitnesslot parameters of table 9. On the other hand, symbol positions in a slot where the UE can monitor the search space can be reported to the base station by the following UE capabilities.

In one example of UE capability 1 (hereinafter FG 3-1), as shown in table 11 below, when there is one Monitoring Occasion (MO) of type 1 and type 3 common search spaces or UE-specific search spaces in a slot, this UE capability refers to a function of monitoring the corresponding MO when the MO's position is within the first 3 symbols in the slot. This UE capability is a mandatory function that all NR-capable UEs may support and whether this function is supported is not explicitly reported to the base station.

TABLE 11

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In one example of UE capability 2 (hereinafter FG 3-2), as shown in table 12 below, when there is one Monitoring Occasion (MO) of a common search space or a UE-specific search space in a slot, this UE capability refers to a function of monitoring a corresponding MO regardless of a start symbol position of the corresponding MO. The UE may optionally support this functionality (optional) and whether or not this functionality is supported may be explicitly reported to the base station.

TABLE 12

In one example of UE capability 3 (hereinafter FG 3-5, 3-5a, 3), this UE capability indicates the mode of MO that the UE can monitor when there is one Monitoring Occasion (MO) of the common search space or UE-specific search space in the slot, as shown in table 13 below. The pattern consists of an interval X between start symbols between different MOs and a maximum symbol length Y of one MO. The combination of (X, Y) supported by the UE may be one or more of { (2, 2), (4, 3), (7, 3) }. The UE may optionally support this UE capability (optional) and whether this functionality is supported and the above (X, Y) combinations may be explicitly reported to the base station.

TABLE 13

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The UE may report to the base station whether UE capability 2 and/or UE capability 3 and related parameters described above are supported. The base station may perform time-axis resource allocation for the common search space and the UE-specific search space according to the reported UE capabilities. When allocating resources, the base station may prevent the UE from locating the MO in a location that cannot be monitored.

[DRX]

Fig. 6 illustrates Discontinuous Reception (DRX).

Discontinuous Reception (DRX) is an operation in which a UE using a service discontinuously receives data in an RRC connection state where a radio link is established between a base station and the UE. When DRX is applied, the UE may turn on the receiver and monitor the control channel at a specific point of time, and turn off the receiver to reduce power consumption of the UE when no data is received for a predetermined period of time. DRX operation may be controlled by the MAC layer device based on various parameters and timers.

Referring to fig. 6, the active time 605 is a time when the UE wakes up and monitors the PDCCH every DRX cycle. The activity time 605 may be defined as follows:

-drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-retransmission timer ul or ra-contentioresolutiontimer is running;

-a scheduling request is sent on PUCCH and in a pending state; or alternatively

The PDCCH indicates that no new transmission of the C-RNTI addressed to the MAC entity is received after successful reception of a random access response to a random access pilot selected by a MAC entity other than the contention based random access pilot.

The drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, ra-contentioresolute and the like are timers whose values are set by the base station, and have a function of configuring the UE to monitor the PDCCH when a predetermined condition is satisfied.

The DRX-onduration timer 615 parameter is used to set the minimum time that the UE is in the awake state in the DRX cycle. The drx-InactivityTimer 620 parameter is used to set the additional wake-up time for the UE when it receives the PDCCH 630 indicating a new uplink or downlink transmission. The drx-retransmission timer dl parameter is used to set the maximum time for which the UE is in the awake state to receive downlink retransmissions in the downlink HARQ process. The drx-retransmission timer ul parameter is used to set the maximum time for which the UE is in the awake state to receive an uplink retransmission grant in the uplink HARQ process. The drx-onDurationTimer, drx-InactivityTimer, drx-retransmission timerdl and drx-retransmission timersl may be set to, for example, time, number of subframes, number of slots, and the like. ra-contentioresolutiontimer is a parameter used to monitor PDCCH in a random access procedure.

The inactive time 610 is a time set to not monitor or receive the PDCCH during the DRX operation, and the remaining time except for the active time 605, during which the DRX operation is performed, may be the inactive time 610. If the PDCCH is not monitored during the active time 605, the UE may enter a sleep or inactive state and reduce power consumption.

The DRX cycle refers to a period in which the UE wakes up to monitor the PDCCH. That is, after the UE monitors the PDCCH, the UE refers to a time interval or on duration occurrence period before monitoring the next PDCCH. There are two types of DRX cycles, namely a short DRX cycle and a long DRX cycle. A short DRX cycle may optionally be applied.

The long DRX cycle 625 is the longest DRX cycle of the two DRX cycles configured in the UE. When operating as long DRX, the UE restarts the DRX-onduration timer 615 at a point in time when the start point (e.g., start symbol) of the DRX-onduration timer 615 has passed the long DRX cycle 625. When operating as a long DRX cycle 625, the UE may start a DRX-onduration timer 615 in a slot after DRX-SlotOffset in a subframe satisfying equation 2 below. Here, drx-SlotOffset refers to the delay before drx-onduration timer 615 starts. The drx-SlotOffset may be set to time, slot number, etc., for example.

[ equation 2]

[ (SFN X10) +subframe number ] modulus (drx-LongCycle) =drx-StartOffset.

In this case, DRX-longcyclestatoffset may be used to define the long DRX cycle 625 and DRX-StartOffset may start subframes of the long DRX cycle 625. The drx-longcyclestatoffset may be set to, for example, time, subframe number, slot number, etc.

[ PDCCH: BD/CCE restriction ]

When configuring multiple search space sets for a UE, the following conditions may be considered in the method of determining the search space sets monitored by the UE.

If the UE receives a value of upper layer signaling moniringcapability config-r16 set to r15 monitoringcapability, the UE defines the number of PDCCH candidates to monitor per slot and the number of CCEs constituting the entire search space (here, the entire search space refers to the entire CCE set corresponding to the joint region of the multiple search space sets). If the UE receives a value of monitoringcapability config-r16 set to r16monitoringcapability, the UE defines the number of PDCCH candidates to monitor per span and the number of CCEs constituting the entire search space (here, the entire search space refers to the entire CCE set corresponding to the joint region of the multiple search space sets).

[ condition 1: limiting the maximum number of PDCCH candidates

As described above, the set value mu (the maximum PDCCH candidate group number that the UE can monitor) according to the upper layer signaling may follow table 14 when a cell set with a subcarrier spacing of 15·2μkhz is defined on a slot basis and table 15 when defined on a span basis.

TABLE 14

μ	Maximum PDCCH candidates per slot and per serving cell (M ^μ )
		0	44
1	36
		2	22
3	20

TABLE 15

[ condition 2: limiting the maximum CCE number

As described above, according to the set value cμ of the upper layer signaling, i.e., the maximum CCE number constituting the entire search space (here, the entire search space refers to the entire CCE set corresponding to the joint region of the plurality of search space sets), table 16 can be followed when slot-based definition is performed in a cell set with a subcarrier spacing of 15·2μ kHz, and table 17 can be followed when span-based definition is performed.

TABLE 16

TABLE 17

For convenience of explanation, a case where both conditions 1 and 2 are satisfied at a specific point in time is defined as "condition a". Therefore, the condition a being not satisfied may mean that at least one of the above-described condition 1 and condition 2 is not satisfied.

[ PDCCH: oversubscription ]

Depending on the configuration of the set of base station search spaces, condition a may not be satisfied at a particular point in time. If the condition a is not satisfied at a specific point of time, the UE may select and monitor only a search space set of which a portion is configured to satisfy the condition a at a corresponding point of time, and the base station may transmit the PDCCH to the selected search space set.

The following method may be followed as a method of selecting some search spaces from the entire set of search spaces.

When condition a of the PDCCH is not satisfied at a specific point of time (slot), the UE (or base station) may preferentially select a search space set of which search space type is configured as a common search space from among search space sets existing at corresponding times, instead of a search space set configured as a UE-specific search space.

When all sets of search spaces configured as a common search space are selected (i.e., if condition a is satisfied even after all search spaces set as a common search space are selected), the UE (or the base station) may select a set of search spaces configured as UE-specific search spaces. In this case, when there are a plurality of search space sets configured as UE-specific search spaces, a search space set having a low search space set index may have a higher priority. The UE (or base station) may select a set of UE-specific search spaces within the range that satisfies condition a, taking priority into account.

[ QCL, TCI State ]

In a wireless communication system, one or more different antenna ports (or alternatively one or more channels, signals, and combinations thereof, but which may be referred to as different antenna ports for convenience in the following description of the present disclosure) may be associated with each other through a quasi co-sited (QCL) configuration, as shown in table 18 below. The TCI state is used to inform QCL relation between PDCCH (or PDCCH DMRS) and another RS or channel, where a certain reference antenna port a (reference rs#a) and another target antenna port B (target rs#b) QCL each other means a channel metric allowing the UE to apply part or all of the large-scale channel parameters estimated from antenna port a to those estimated from antenna port B. QCL may need to correlate different parameters depending on the situation, e.g. 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by doppler shift and doppler spread, 3) Radio Resource Management (RRM) affected by average gain, 4) Beam Management (BM) affected by spatial parameters, etc. Thus, NR supports four types of QCL relationships, as shown in Table 18 below.

TABLE 18

QCL type	Large scale characteristics
		A	Doppler shift, doppler spread, average delay, delay spread
B	Doppler shift, doppler spread
		C	Doppler shift, average delay
D	Spatial reception parameters

The spatial RX parameters may collectively refer to some or all of various parameters such as angle of arrival (AoA), power Angle Spectrum (PAS) of AoA, angle of departure (AoD), PAS of AoD, transmit/receive channel association, transmit/receive beamforming, spatial channel association, and the like.

QCL-related may be established with the UE through RRC parameters TCI-State and QCL-Info as shown in table 19 below. Referring to table 19, the base station may configure one or more TCI states to the UE and inform the UE of the RS with respect to the ID referencing the TCI states, i.e., at most two QCL relationships of the target RS (QCL-Type 1 and QCL-Type 2). In this case, each QCL information (QCL-Info) included in each TCI state includes a serving cell index and a BWP index of the reference RS indicated by the corresponding QCL information, a type and ID of the reference RS, and a QCL type as shown in table 18.

TABLE 19

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Fig. 7 shows an example of allocating base station beams according to TCI state configuration. Referring to fig. 7, a base station may transmit information about N different beams to a UE through N different TCI states. For example, if n=3, as shown in fig. 7, the base station may announce: the QCL-Type2 parameter included in the three TCI states 700, 705 and 710 is associated with CSI-RS or SSB corresponding to different beams, and the antenna ports referring to the different TCI states 700, 705 and 710 are associated with different spatial RX parameters, i.e., different beams by setting QCL Type D.

Tables 20 to 24 below show the effective TCI state configuration according to the target antenna port type.

Table 20 shows an effective TCI state configuration when the target antenna port is CSI-RS (TRS) for tracking. TRS refers to NZP CSI-RS in which a repetition parameter is not set, but TRS-info is set to true in CSI-RS. In the case of setting 3 in table 20, it is available for aperiodic TRS.

TABLE 20 effective TCI State configuration when the target antenna port is the CSI-RS (TRS) for tracking

TABLE 20

Table 21 shows an effective TCI state configuration when the target antenna port is a CSI-RS for CSI. The CSI-RS for CSI refers to NZP CSI-RS in which a parameter indicating repetition (e.g., a repetition parameter) is not set, and trs-info is not set to true in CSI-RS either.

TABLE 21 effective TCI State configuration when the target antenna port is the CSI-RS for CSI

TABLE 21

Table 22 shows the effective TCI state configuration when the target antenna port is a CSI-RS for beam management (BM, the same meaning as CSI-RS for L1RSRP reporting). CSI-RS for BM refers to NZP CSI-RS in which the repetition parameter is set to on or off, and trs-info is also not set to true in CSI-RS. TABLE 22 effective TCI State configuration when the target antenna port is CSI-RS for BM (for L1RSRP reporting)

TABLE 22

Table 23 shows the effective TCI state configuration when the target antenna port is PDCCH DMRS. TABLE 23 effective TCI State configuration when target antenna port is PDCCH DMRS

TABLE 23

Table 24 shows the effective TCI state configuration when the target antenna port is PDSCH DMRS. TABLE 24 effective TCI State configuration when the target antenna port is PDSCH DMRS

TABLE 24

According to tables 20 to 24, a typical QCL configuration method is to set the target antenna port and the reference antenna port of each step to "SSB" - > "TRS" - > "CSI-RS for CSI or CSI-RS for BM or PDCCH DMRS or PDSCH DMRS" and operate it. In this way, the reception operation of the UE can be assisted by linking the statistical characteristics measured from the SSB and the TRS to each antenna port. [ PDCCH: related to TCI State

Specifically, TCI state combinations applicable to PDCCH DMRS antenna ports are shown in table 25 below. In table 25, the fourth row is a combination of assumptions by the UE before RRC setup, and is not settable after RRC.

TABLE 25

NR supports a hierarchical signaling method as shown in fig. 8 for dynamically allocating PDCCH beams. Referring to fig. 8, a base station may configure N TCI states 805, 810, 820 to a UE through RRC signaling 800, and some of the TCI states may be configured as TCI states for CORESET 825. Thereafter, the base station may indicate one of the TCI states 830, 835 and 840 for CORESET to the UE through MAC CE signaling 845. Thereafter, the UE may receive the PDCCH based on beam information included in the TCI state indicated by the MAC CE signaling.

Fig. 9 shows a TCI indication MAC CE signaling structure for PDCCH DMRS.

Referring to fig. 9, TCI indication MAC CE signaling for PDCCH DMRS may consist of 2 bytes (16 bits) and include a 5-bit serving cell ID 915, a 4-bit CORESET ID 920, and a 7-bit TCI status ID 925.

Fig. 10 shows an example of a beam configuration of a control resource set (CORESET) and search space according to the above description.

Referring to fig. 10, the base station may indicate one of the TCI status lists included in the CORESET 1000 configuration through MAC CE signaling 1005. Thereafter, until another TCI state is indicated to the corresponding CORESET through another MAC CE signaling, the UE considers the same QCL information (beam # 1) 1005 to be applied to one or more search spaces 1010, 1015, and 1020 connected to the CORESET. The above PDCCH beam allocation method has a disadvantage in that it is difficult to indicate a beam change faster than a MAC CE signaling delay, and the same beam is uniformly applied to all CORESET regardless of search space characteristics, making it difficult to operate a flexible PDCCH beam. Hereinafter, embodiments of the present disclosure provide a more flexible PDCCH beam configuration and operation method. In the following, in describing embodiments of the present disclosure, several distinguishable examples are provided for convenience of description, but these examples are not mutually exclusive and may be applied by being appropriately combined with each other according to circumstances.

The base station may configure one or more TCI states for a specific control region of the UE and may activate one of the configured TCI states through a MAC CE activation command. For example, { TCI state #0, TCI state #1, and TCI state #2} are configured in the control region #1, and the base station can transmit a command for activation to the UE through the MAC CE to assume TCI state #0 as the TCI state of the control region # 1. Based on the TCI state activation command received via the MAC CE, the UE may correctly receive the DMRS of the corresponding control region based on QCL information in the activated TCI state.

For the control region (control region # 0) with index set to 0, if the UE has not received the MAC CE activation command of the TCI state of the control region #0, the UE may assume that the DMRS transmitted in the control region #0 is QCL with the SS/PBCH block identified by the non-contention-based random access procedure during the initial access procedure or not triggered by the PDCCH command.

For a control region (control region #x) with an index set to a value other than 0, if the UE has not received the configured TCI state of the control region #x or has received one or more configured TCI states but has not received a MAC CE activation command activating one of the configured TCI states, the UE may assume that the DMRS transmitted in the control region #x is QCL with the SS/PBCH block identified in the initial access procedure.

[ PDCCH: related to QCL prioritization rules

The QCL priority determining operation of the PDCCH will be described in detail below.

The UE may operate as carrier aggregation in a single cell or frequency band, and when a plurality of control resource sets present in an active bandwidth part within a single or a plurality of subcarriers overlap in time while having the same or different QCL-type characteristics within a specific PDCCH monitoring period, the UE may select a specific control resource set according to a QCL priority determination operation and monitor the control resource set having the same QCL-type characteristics as the corresponding control resource set. That is, only one QCL-type feature can be received when multiple control resource sets overlap in time. In this case, the criteria for determining QCL priority may be as follows:

criterion 1. Among the subcarriers comprising a common search space, the subcarrier corresponding to the lowest index is connected to the common search space, the control resource set having the lowest index; and

criterion 2. Among the subcarriers comprising the UE-specific search space, the subcarrier corresponding to the lowest index is connected to the set of control resources with the lowest index that are connected to the UE-specific search space.

As described above, when the corresponding standard is not satisfied, each standard applies the following standard. For example, when the control resource sets overlap in time within a specific PDCCH monitoring period, if all control resource sets are not connected to a common search space, but to a UE-specific search space, i.e., if criterion 1 is not satisfied, the UE may omit the application of criterion 1 and apply criterion 2.

When the UE selects the control resource set based on the above criteria, the following two additional matters may be considered for QCL information configured in the control resource set. First, if a first control resource set has a first CSI-RS having a QCL-type relationship as a reference signal, the first CSI-RS having the QCL-type relationship is a first SSB, and another second control resource set having the QCL-type relationship is a first SSB, the UE may consider that the first control resource set and the second control resource set have different QCL-type characteristics. Second, if the first control resource set has a first CSI-RS having a QCL-TypeD relation as a reference signal, which is configured on a first subcarrier, the first CSI-RS having a QCL-TypeD relation is a first SSB, the second control resource set has a second CSI-RS having a QCL-TypeD relation as a reference signal, which is configured on a second subcarrier, and the reference signal of the second CSI-RS having a QCL-TypeD relation is the same as the first SSB, the UE may consider that the two control resource sets have the same QCL-TypeD characteristics.

Fig. 12 illustrates a method for a UE to select a receivable control resource set considering priority when receiving a downlink control channel in a wireless communication system according to one embodiment of the present disclosure. As an example, the UE may be configured to receive multiple sets of control resources overlapping in time in a specific PDCCH monitoring period 1210, and the multiple sets of control resources may be connected to a common search space or a UE-specific search space of multiple cells. Within the corresponding PDCCH monitoring period, in the first bandwidth part 1200 of the first cell there may be a first set of control resources 1215 connected to the first common search space, and in the first bandwidth part 1205 of the second cell there may be a first set of control resources 1220 connected to the first common search space, and a second set of control resources 1225 connected to the second UE-specific search space. The control resource sets 1215 and 1220 may have a QCL-TypeD relationship with the first CSI-RS resources configured in the first bandwidth part of the first cell, and the control resource set 1225 may have a QCL-TypeD relationship with the first CSI-RS resources configured in the first bandwidth part of the second cell.

Thus, if standard 1 is applied to the corresponding PDCCH monitoring period 1210, all other control resource sets, e.g., the first control resource set 1215, having QCL-type reference signals may be received. Thus, the UE may receive the control resource sets 1215 and 1220 in the corresponding PDCCH monitoring period 1210. As another example, the UE may be configured to receive multiple sets of control resources overlapping in time in a specific PDCCH monitoring period 1240, and the multiple sets of control resources may be connected to a common search space or a UE-specific search space of multiple cells. Within the corresponding PDCCH monitoring period, in the first bandwidth portion 1230 of the first cell there may be a first set of control resources 1245 connected to the first UE-specific search space and a second set of control resources 1250 connected to the second UE-specific search space, and in the first bandwidth portion 1235 of the second cell there may be a first set of control resources 1255 connected to the first UE-specific search space and a second set of control resources 1260 connected to the third UE-specific search space.

Control resource sets 1245 and 1250 may have a QCL-TypeD relationship with first CSI-RS resources configured in a first bandwidth portion of a first cell, and control resource set 1255 may have a QCL-TypeD relationship with first CSI-RS resources configured in a first bandwidth portion of a second cell, and control resource set 1260 may have a QCL-TypeD relationship with second CSI-RS resources configured in a first bandwidth portion of the second cell. However, if criterion 1 is applied to the corresponding PDCCH monitoring period 1240, there is no common search space, so the next criterion 2 may be applied. If criterion 2 is applied to the corresponding PDCCH monitoring period 1240, all other control resource sets, e.g., control resource set 1245, with QCL-type reference signals may be received. Thus, the UE may receive the control resource sets 1245 and 1250 in the corresponding PDCCH monitoring period 1240.

[ Rate matching/puncture correlation ]

The rate matching operation and the puncturing operation will be described in detail below.

When the time and frequency resource a of transmitting an arbitrary symbol sequence a overlaps with the arbitrary time and frequency resource B, the rate matching or puncturing operation can be regarded as a transmission/reception operation of the channel a in consideration of the resource C in the overlapping region of the resource a and the resource B. The specific operation may follow the following.

[ Rate matching operation ]

The base station can only map and transmit the channel a of the remaining resource region except for the resource C corresponding to the region overlapping with the resource B among all the resources a transmitted to the UE via the symbol sequence a. For example, when the symbol sequence a is composed of { symbol #1, symbol #2, symbol #3, and symbol 4}, resource a is { resource #1, resource #2, resource #3, and resource #4}, and resource B is { resource #3, and resource #5}, the base station may map the symbol sequence a to { resource #1, resource #2, and resource #4}, that is, the remaining resources of resource a except { resource #3} corresponding to resource C, in order, and may transmit the symbol sequence a. Thus, the base station can map and transmit symbol sequences { symbol #1, symbol #2, and symbol #3} to { resource #1, resource #2, and resource #4} respectively.

The UE may determine the resources a and B from the scheduling information of the base station regarding the symbol sequence a, and in this way, the UE may determine the resource C, i.e., the region where the resources a and B overlap. The UE may receive the symbol sequence a assuming that the symbol sequence a is mapped and transmitted in the remaining region except for the resource C among all the resources a. For example, when the symbol sequence a is composed of { symbol #1, symbol #2, symbol #3, and symbol 4} and the resource a is { resource #1, resource #2, resource #3, and resource #4} and the resource B is { resource #3, and resource #5}, the UE may receive assuming that the symbol sequence a is mapped to { resource #1, resource #2, resource #4}, i.e., the remaining resources of the resource a except for the resource C corresponding to { resource #3}, in order. Thus, the UE may assume that the symbol sequence { symbol #1, symbol #2, symbol #3} is mapped to { resource #1, resource #2, resource #4} and transmitted, and may perform a subsequent series of reception operations.

[ puncture operation ]

When there is a resource C corresponding to an area overlapping with the resource B among all the resources a for transmitting the symbol sequence a to the UE, the base station may map the symbol sequence a to the entire resource a, but cannot perform transmission in a resource area corresponding to the resource C, and may perform transmission only in the remaining resource areas other than the resource C among the resources a. For example, when the symbol sequence a is composed of { symbol #1, symbol #2, symbol #3, and symbol 4}, the resource a is { resource #1, resource #2, resource #3, and resource #4}, and the resource B is { resource #3, and resource #5}, the base station may map the symbol sequence a { symbol #1, symbol #2, symbol #3, and symbol #4} to the resource a { resource #1, resource #2, resource #3, and resource #4}, respectively, and only the symbol sequences { symbol #1, symbol #2, and symbol #4} corresponding to { resource #1, resource #2, and resource #4}, that is, the remaining resources other than { resource #3} corresponding to resource C in the resource a, may not be transmitted. Thus, the base station can map and map the symbol sequences { symbol #1, symbol #2, and symbol #4} to { resource #1, resource #2, and resource #4} respectively.

The UE may determine the resources a and B from the scheduling information of the base station regarding the symbol sequence a, and in this way, may determine the resource C, i.e., the region where the resources a and B overlap. The UE may receive the symbol sequence a assuming that the symbol sequence a is mapped and transmitted in the remaining region except for the resource C among all the resources a. For example, when the symbol sequence a is composed of { symbol #1, symbol #2, symbol #3, and symbol 4} and the resource a is { resource #1, resource #2, resource #3, and resource #4} and the resource B is { resource #3, and resource #5}, the UE may assume that the symbol sequences a { symbol #1, symbol #2, symbol #3, and symbol #4} are each mapped to the resource a { resource #1, resource #2, resource #3, and resource #4}, but { symbol #3} mapped to the { resource #3} corresponding to the resource C is not transmitted, and may receive, assuming that the symbol sequences { symbol #1, symbol #2, and symbol #4} corresponding to { resource #1, resource #2, and resource #4}, that the remaining resources other than { resource #3} corresponding to the resource C are mapped and transmitted from the resource a. Thus, the UE may assume that the symbol sequence { symbol #1, symbol #2, symbol #4} is mapped to { resource #1, resource #2, resource #4} and transmitted, and may perform a subsequent series of reception operations.

A method of configuring rate matching resources for rate matching in a 5G communication system will be described hereinafter. Rate matching refers to adjusting the size of a signal according to the amount of resources that can transmit the signal. For example, rate matching of a data channel may refer to adjusting the size of data accordingly without mapping and transmitting the data channel for a particular time and frequency resource region.

Fig. 11 a method for a base station and a UE to transmit and receive data in consideration of a downlink data channel and a rate matching resource.

Fig. 11 shows a downlink data channel (PDSCH) 1101 and rate matching resources 1102. The base station may configure one or more rate matching resources 1102 to the UE through upper layer signaling (e.g., RRC signaling). Configuration information for rate matching resource 1102 may include time domain resource allocation information 1103, frequency domain resource allocation information 1104, and period information 1105. Hereinafter, a bitmap corresponding to the frequency domain resource allocation information 1104 is referred to as a "first bitmap", a bitmap corresponding to the time domain resource allocation information 1103 is referred to as a "second bitmap", and a bitmap corresponding to the period information 1105 is referred to as a "third bitmap". When all or a portion of the time and frequency resources of the scheduled data channel 1101 overlap with the set rate matching resources 1102, the base station may rate match and transmit the data channel 1101 in the rate matching resources 1102 portion and the UE may receive and decode the data channel 1101 after assuming that the data channel 1102 is rate matched in the rate matching resources 1102 portion.

The base station may dynamically inform the UE of whether to rate match the data channels in the configured rate matching resource section through additional configuration (a "rate matching indicator" corresponding to the DCI format described above) through DCI. Specifically, the base station may select and group some of the configured rate matching resources into rate matching resource groups, and may indicate to the UE whether to rate match the data channels of each rate matching resource group through DCI by using a bitmap method. For example, when four rate matching resources of rmr#1, rmr#2, rmr#3, and rmr#4 are configured, the base station may configure rmg#1= { rmr#1, rmr#2} and rmg#2= { rmr#3, rmr#4} as a rate matching group, and may indicate to the UE whether rates in rmg#1 and rmg#2 match using a 2-bit bitmap in the DCI field. For example, "1" may be indicated when rate matching is to be performed, and "0" may be indicated when rate matching is not to be performed.

The 5G supports granularity of "RB symbol level" and "RE level" as a method of configuring the above-described rate matching resource to the UE. More specifically, the following configuration method may be followed.

[ RB symbol level ]

For each bandwidth portion configured by upper layer signaling, the UE may receive at most four RateMatchPatterns, and one RateMatchPattern may include the following:

The reserved resources as part of the bandwidth may comprise resources that configure the time and frequency resource areas of the corresponding reserved resources as a combination of RB-level and symbol-level bitmaps on the frequency axis. The reserved resources may span one or two time slots. A time domain and frequency domain repeated time domain pattern (periodic and pattern) consisting of each RB-level and symbol-level bitmap pair may be additionally configured; and

-may comprise time-domain and frequency-domain resource regions configured to control the resource set in the bandwidth part, and resource regions corresponding to time-domain patterns configured to repeat the search space configuration of the resource regions.

[ RE level ]

The UE may receive the following configured by upper layer signaling:

as configuration information (LTE-CRS-to-matching around) of REs corresponding to LTE CRS (cell-specific reference signal or common reference signal) mode, the port numbers of LTE CRS (nrofCRS-Ports) and LTE-CRS-vshift values (v shift) may be included, center subcarrier position information (carrier freqdl) of LTE carrier from a reference frequency point (e.g., reference point a), bandwidth size (carrier bandwidth dl) information of LTE carrier, subframe configuration information (MBSFN-subframe configuration list) corresponding to MBSFN (multicast broadcast single frequency network), and the like. The UE may determine, based on the above information, a position of the CRS in an NR slot corresponding to the LTE subframe; and

Configuration information of a set of resources corresponding to one or more ZP (zero power consumption) CSI-RS in the bandwidth part may be included.

[ related to LTE CRS Rate matching ]

Next, the rate matching procedure of the LTE CRS described above will be described in detail. For coexistence of LTE and NR, NR provides the functionality to configure a cell-specific reference signal (CRS) pattern of LTE as an NR UE. More specifically, CRS patterns may be provided by RRC signaling, including at least one parameter of the ServingCellConfig Information Element (IE) or ServingCellConfigCommon IE. Examples of such parameters may include lte-CRS-ToMatchAround, lte-CRS-Pattern List1-r16, lte-CRS-Pattern List2-r16, CRS-RateMatch-PerCORESETPoolIndex-r16, and so forth.

Rel-15 NR provides the functionality to configure one CRS pattern for each serving cell by means of the lte-CRS-to-matcharound parameter. In Rel-16 NR, the above functionality has been extended to be able to configure multiple CRS patterns for each service element. More specifically, one CRS pattern per LTE carrier may be configured in a single TRP (transmission reception point) configured UE, in a multi TRP configured UE, and two CRS patterns per LTE carrier may be configured. For example, in a single TRP configured UE, up to three CRS patterns per serving cell may be configured by the lte-CRS-Pattern List1-r16 parameters. For another example, CRS may be configured for each TRP in a multi-TRP configured UE. That is, CRS pattern of TRP1 may be configured by the lte-CRS-Pattern List1-r16 parameters, and CRS pattern of TRP2 may be configured by the lte-CRS-Pattern List2-r16 parameters. On the other hand, when two TRPs are configured as described above, it is determined by the CRS pattern of TRP1 and TRP2 to be applied to a specific PDSCH at the same time or CRS pattern of only one TRP is applied by the CRS-rateMatch-percoresetpoinddex-r 16 parameter, and if the CRS pattern of CRS-rateMatch-percoresetpoinddex-r 16 parameter is configured to be enabled, only one TRP CRS pattern is applied, and in other cases, two TRP CRS patterns are to be applied.

Table 26 shows ServingCellConfig IE including CRS patterns, and table 27 shows rategaputtmatternlte-CRS IEs including at least one parameter of CRS patterns.

TABLE 26

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TABLE 27

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[ PDSCH: related to frequency resource Allocation

Fig. 14 illustrates an example of frequency axis resource allocation of a Physical Downlink Shared Channel (PDSCH) in a wireless communication system according to one embodiment of the disclosure.

Fig. 14 shows three frequency axis resource allocation methods of type 0 1400, type 1 1405, and dynamic switch 1410, which can be configured by an upper layer in an NR wireless communication system.

Referring to fig. 14, if a UE is configured to use resource type 0 only through upper layer signaling 1400, some Downlink Control Information (DCI) for allocating PDSCH to a corresponding UE has a bitmap composed of NRBG bits. The conditions thereof will be described again below. In this case, NRBG refers to the number of Resource Block Groups (RBGs) determined according to the BWP Size allocated by the BWP indicator and the upper layer parameter RBG-Size, as shown in table 28 below, and data is transmitted in RBGs denoted as 1 in the bitmap.

TABLE 28

Bandwidth portion size	Configuration 1	Configuration 2
			1-36	2	4
37-72	4	8
			73-144	8	16
145-275	16	16

If the UE is configured to use resource type 1 only through upper layer signaling 1405, some DCI for allocating PDSCH to the UE has a sequence of information represented by Bit-composed frequency domain resource allocation information. The conditions thereof will be described again below. The base station may configure the starting VRB 1420 and the length 1425 of the frequency domain resources allocated consecutively therefrom.

If the UE is configured to use both resource type 0 and resource type 1 through upper layer signaling 1410, some DCI for allocating PDSCH to the UE has frequency domain resource allocation information consisting of bits for configuring a payload 1415 of resource type 0 and a larger value 1435 of payloads 1420 and 1425 for configuring resource type 1. The conditions thereof will be described again below. In this case, a bit may be added to the front end portion (MSB) of the frequency band resource allocation information in the DCI, and when the bit is 0, the bit may represent that the resource type 0 is used, and when the bit is 1, the bit may represent that the resource type 1 is used.

PDSCH/PUSCH: related to time resource Allocation

A method of allocating time domain resources for a data channel in a next generation wireless communication system (5G or NR system) will be described hereinafter.

The base station may configure a time domain resource allocation information table for a downlink shared channel (PDSCH) and an uplink shared channel (PUSCH) to the UE through upper layer signaling (e.g., RRC signaling). For PDSCH, a table consisting of maximum maxNrofDL-allocations=16 entries may be configured, and for PUSCH, a table consisting of maximum maxNrofUL-allocations=16 entries may be configured. In one embodiment, PDCCH-to-PDSCH slot timing (corresponding to a time interval in a slot unit between a time when the PDCCH is received and a time when the PDSCH scheduled by the received PDCCH is transmitted, denoted by K0), PDCCH-to-PUSCH slot timing (corresponding to a time interval in a slot unit between a time when the PDCCH is received and a time when the PUSCH scheduled by the received PDCCH is transmitted, denoted by K2), information on a position and length of a starting symbol in a slot where the PDSCH or PUSCH is scheduled, a mapping type of the PDSCH or PUSCH, and the like may be included in the time domain resource allocation information. For example, the following information of table 29 or table 30 may be transmitted from the base station to the UE.

TABLE 29

TABLE 30

The base station may announce an entry in a time domain resource allocation information table to the UE through L1 signaling (e.g., DCI) (e.g., indicated by a "time domain resource allocation" field within the DCI). The UE may acquire time domain resource allocation information on the PDSCH or PUSCH based on DCI received from the base station.

Fig. 15 illustrates an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the disclosure.

Referring to fig. 15, the base station may indicate a time axis position of PDSCH resources according to subcarrier spacing (SCS) (μpdsch, μpdcch) of a data channel and a control channel configured with an upper layer, a scheduling offset value (K0), and an OFDM symbol start position 1500 and a length 1505 within one slot dynamically indicated by DCI.

Fig. 16 illustrates an example of time axis resource allocation according to subcarrier spacing of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

Referring to fig. 16, when the subcarrier spacing of the data channel and the control channel is the same 1600 (μpdsch=μpdcch) because the number of slots for the data channel and the control channel is the same, the base station and the UE may generate a scheduling offset according to a predetermined slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel is different 1605 (μpdsch+.μpdcch)) due to the different number of slots for the data channel and the control channel, the base station and the UE may generate a scheduling offset according to a predetermined slot offset K0 based on the subcarrier spacing of the PDCCH.

[ PDSCH: treatment time ]

Next, the time of the PDSCH processing procedure will be described. When the base station schedules the UE to transmit the PDSCH using the DCI format 1_0, 1_1, or 1_2, the UE may need PDSCH processing time to receive the PDSCH by applying a transmission method (modulation/demodulation, coding indication index (MCS), demodulation reference signal related information, time and frequency resource allocation information, etc.) indicated by the DCI. NR defines PDSCH processing time in consideration of this point. The PDSCH processing time of the UE may follow the following equation 3.

[ equation 3]

T _proc，1 ＝(N ₁ +d _1，1 +d ₂ )(2018+144) _κ 2 ^-μ T _C +T _ext 。

Each variable in Tproc,1 described in equation 3 above may have the following meaning:

-N1: the number of symbols determined according to the UE processing function 1 or 2 and the parameter set μ determined according to the function of the UE. N1 may have values in table 31 when reported as UE processing function 1 according to a function report of the UE, and may have values in table 32 when reported as UE processing function 2 according to a function report of the UE and configured by upper layer signaling that may use UE processing function 2. The parameter set μmay correspond to the minimum value among μpdcch, μpdsch, μul to maximize Tproc,1, and μpdcch, μpdsch, and μul may refer to the parameter set of the PDCCH scheduling PDSCH, the parameter set of the scheduled PDSCH, and the parameter set of the uplink channel through which HARQ-ACK is transmitted.

TABLE 31 PDSCH processing time in case of PDSCH processing function 1

TABLE 31

Table 32 PDSCH processing time in case of PDSCH processing function 2

TABLE 32

-K:64; text: when the UE uses the shared spectrum channel access method, the UE may calculate "Text" and apply the "Text" to the PDSCH processing time. Otherwise, assume "Text" is 0;

-if l1, which indicates a PDSCH DMRS position value, is 12, then the value of N1.0 of table 31 is 14, otherwise the value of N1.0 is 13;

-for PDSCH mapping type a, d1,1 is 7-i if the last symbol of PDSCH is the i-th symbol in the slot in which PDSCH is transmitted and i <7, otherwise d1,1 is 0; and

-d2: when PUCCHs with high priority indexes and PUCCHs or PUSCHs with low priority indexes overlap in time, d2 of the PUCCHs with high priority indexes may be set to a value reported by the UE. Otherwise, d2 is 0.

When PDSCH mapping type B is used for UE processing function 1, the value of d1,1 is determined from L (the number of symbols of the scheduled PDSCH) and d (the number of overlapping symbols between the PDCCH of the scheduled PDSCH and the scheduled PDSCH):

-if L is ≡ 7, d1, 1=0;

-if L is ≡4 and L is ≡6, d1, 1=7-L;

-if l=3, d1, 1=min (d, 1); and is also provided with

-if l=2, d1, 1= 3+d.

When PDSCH mapping type B is used for UE processing function 2, the value of d1,1 is determined as follows based on L (the number of symbols of the scheduled PDSCH) and the number of overlapping symbols d between the PDCCH of the scheduled PDSCH and the scheduled PDSCH:

-if L is ≡ 7, d1, 1=0;

-if L is ≡4 and L is ≡6, d1, 1=7-L;

-if l=2;

-d 1,1 = 3 if the scheduled PDCCH is present in a CORESET consisting of three symbols and the corresponding CORESET and the scheduled PDSCH have the same starting symbol.

-otherwise, d1, 1=d; and is also provided with

Given that the UE supports function 2 in the serving cell, PDSCH processing time may be applied according to UE processing function 2 when the UE sets upper layer signaling type2Enabled to Enabled for the corresponding cell.

The UE may transmit a valid HARQ-ACK message if the position of the first uplink transmission symbol of the PUCCH including HARQ-ACK information (the corresponding position may be regarded as K1-, which may be defined as the transmission time of HARQ-ACK, PUCCH resources for HARQ-ACK transmission, and timing advance effect) is not earlier than the first uplink transmission symbol occurring after 1 time from the last symbol 1 of the PDSCH. That is, the UE can transmit the PUCCH including the HARQ-ACK only when the PDSCH processing time is sufficient. Otherwise, the UE may not be able to provide the base station with valid HARQ-ACK information corresponding to the scheduled PDSCH. Tproc,1 may be used for normal or extended CP. For PDSCH with two PDSCH transmission positions within a slot, d1,1 is calculated based on the first PDSCH transmission position within the corresponding slot.

[ PDSCH: reception preparation time for Cross-Carrier scheduling ]

Next, in the case of cross-carrier scheduling in which a parameter set μpdcch transmitting a scheduled PDCCH and a parameter set μpdsch transmitting a PDSCH scheduled by a corresponding PDCCH are different from each other, N-PDSCH, i.e., a PDSCH reception preparation time of a UE defined for a time interval between the PDCCH and the PDSCH, will be described.

If μpdcch < μpdsch, the transmission time of the scheduled PDSCH is not earlier than the first symbol of the slot occurring after the Npdsch symbol from the last symbol of the PDCCH for which PDSCH is scheduled. The transmission symbol of the corresponding PDSCH may include DM-RS.

If μpdcch > μpdsch, the transmission time of the scheduled PDSCH may be after Npdsch symbol from the last symbol of the PDCCH for which PDSCH is scheduled. The transmission symbol of the corresponding PDSCH may include DM-RS.

TABLE 33]N according to the PDCCH subcarrier spacing scheduled _pdsch

TABLE 33

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[ associated with SRS ]

Next, an uplink channel reasoning method using Sounding Reference Signal (SRS) transmission of the UE will be described. The base station may configure at least one SRS configuration for each uplink BWP to transmit configuration information regarding SRS transmission to the UE, and may also configure at least one SRS resource set for each SRS configuration.

For example, the base station and the UE may exchange upper layer signaling information in order to transmit information about the SRS resource set as follows:

srs-ResourceSetId: SRS resource set index;

srs-ResourceIdList: an SRS resource index set referenced by the SRS resource set;

-resourceType: the timeline transmission configuration of SRS resources referenced in the SRS resource set may be configured as one of "periodic," semi-persistent, "and" aperiodic. If configured to be "periodic" or "semi-persistent," the associated CSI-RS information may be provided according to the usage of the SRS resource set. If configured as "aperiodic", an aperiodic SRS resource trigger list and slot offset information may be provided, and associated CSI-RS information may be provided according to the use case of the SRS resource set;

-use case: the case configuration of SRS resources referenced in the SRS resource set, and may be configured as one of "beam management", "codebook", "non-codebook", and "antenna switching"; and

alpha, p0, pathassReferenceRS, srs-PowerControlAdjust states: parameter settings for adjusting transmit power of SRS resources referenced in a set of SRS resources are provided.

It can be appreciated that the UE follows information in the SRS resource set configured for SRS resources included in the SRS resource index set referenced in the SRS resource set.

Further, the base station and the UE may transmit/receive upper layer signaling information in order to transmit separate configuration information regarding SRS resources. For example, the separate configuration information regarding SRS resources may include time-frequency axis mapping information within SRS resource slots, which may include frequency hopping information within or between SRS resource slots. Further, the separate configuration information regarding the SRS resource may include a timeline transmission configuration of the SRS resource, and may be configured as one of "periodic", "semi-persistent", and "aperiodic". The separate configuration information regarding the SRS resources may be limited to have the same timeline transmission configuration as the SRS resource set including the SRS resources. The separate configuration information about the SRS resource may also include an SRS resource transmission period and a slot offset (e.g., periodic and offset) if the timeline transmission configuration of the SRS resource is configured to be "periodic" or "semi-persistent.

The base station may activate, deactivate, or trigger SRS transmission to the UE through upper layer signaling, including RRC signaling, MAC CE signaling, or L1 signaling (e.g., DCI). For example, the base station may activate or deactivate periodic SRS transmission directed to the UE through upper layer signaling. The base station may indicate that the active resourceType is configured as a set of "periodic" SRS resources by upper layer signaling, and the UE may transmit SRS resources referenced in the set of active SRS resources. The time-frequency axis resource mapping in the transmitted SRS resource slots follows the resource mapping information set in the SRS resources and the slot mapping including the transmission period and slot offset follows the periodicity and offset set in the SRS resources. In addition, the spatial domain transmission filter applied to the SRS resource to be transmitted may refer to spatial relationship information set in the SRS resource, or may refer to associated CSI-RS information set in the SRS resource set including the SRS resource. The UE may transmit SRS resources in an uplink BWP activated for the periodic SRS resources activated through the upper layer signaling.

For example, the base station may activate or deactivate semi-persistent SRS transmission to the UE through upper layer signaling. The base station may indicate that the SRS resource set is activated through MAC CE signaling, and the UE may transmit SRS resources referenced in the activated SRS resource set. The SRS resource set activated through MAC CE signaling may be limited to only the SRS resource set with the resourceType set to be semi-persistent. The time-frequency axis resource mapping in the slots of the SRS resource to be transmitted follows the set of resource mapping information in the SRS resource, and the slot mapping including the transmission period and the slot offset follows the periodicity and the offset set in the SRS resource. Further, the spatial domain transmission filter applied to the SRS resource to be transmitted may refer to spatial relationship information configured in the SRS resource, or may refer to associated CSI-RS information configured in the SRS resource set including the SRS resource. If the spatial relationship information is configured in the SRS resource without following the above configuration, the spatial domain transmission filter may be determined by referring to the configuration information of the spatial relationship information transmitted through MAC CE signaling activating the semi-persistent SRS transmission. The UE may transmit SRS resources in an uplink BWP activated for the semi-persistent SRS resources activated through upper layer signaling.

For example, the base station may trigger aperiodic SRS transmission directed to the UE through DCI. The base station may indicate one of aperiodic SRS resource triggers (aperiodic SRS-resource trigger) through an SRS request field of the DCI. The UE may understand that the SRS resource set, including the aperiodic SRS resource trigger indicated by the DCI in the aperiodic SRS resource trigger list, has been triggered in the SRS resource set configuration information. The UE may transmit SRS resources referenced in the triggered SRS resource set. The time-frequency axis resource mapping in the slot of the SRS resource to be transmitted follows the resource mapping information configured in the SRS resource.

Further, the slot map of the SRS resource to be transmitted may be determined by a slot offset between the PDCCH including the DCI and the SRS resource, which may refer to a value included in a slot offset set configured in the SRS resource set. Specifically, the slot offset between the PDCCH including the DCI and the SRS resource may apply a value indicated by the time domain resource allocation field of the DCI in an offset value included in the slot offset set configured in the SRS resource set. Further, the spatial domain transmission filter applied to the SRS resource to be transmitted may refer to spatial relationship information configured in the SRS resource, or may refer to associated CSI-RS information configured in the SRS resource set including the SRS resource. The UE may transmit SRS resources in uplink BWP activated for the aperiodic SRS resources triggered by the DCI.

When the base station triggers aperiodic SRS transmission directed to the UE through DCI, a minimum time interval may be required between a PDCCH including DCI triggering the aperiodic SRS transmission and the SRS to be transmitted in order for the UE to transmit the SRS by applying configuration information on SRS resources. The SRS transmission time interval of the UE may be defined as the number of symbols between first symbols on which the first transmitted SRS resource is mapped among SRS resources transmitted from the last symbol of the PDCCH including DCI triggering aperiodic SRS transmission. The minimum time interval may be determined by referring to a PUSCH preparation procedure time required for the UE to prepare PUSCH transmission. Further, the minimum time interval may have different values depending on the usage location of the SRS resource set including the SRS resource to be transmitted.

For example, the minimum time interval may refer to an N2 symbol for which the PUSCH preparation procedure time of the UE is determined, taking into consideration the UE processing function according to the function of the UE. Further, in consideration of the use of the SRS resource set including the SRS resource to be transmitted, if the use of the SRS resource set is configured as "codebook" or "antiswitching", the minimum time interval may be set to N2 symbols, and if the destination of the SRS resource set is configured as "non codebook" or "beam management", the minimum time interval is set to N2+14 symbols. The UE may transmit the aperiodic SRS when the time interval of the aperiodic SRS transmission is greater than or equal to the minimum time interval, and may ignore DCI triggering the aperiodic SRS when the time interval of the aperiodic SRS transmission is less than the minimum time interval.

TABLE 34

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The sputialrationinfo configuration information of table 34 is to apply beam information of a corresponding reference signal to a beam for transmitting a corresponding SRS with reference to one reference signal. For example, the configuration of the spatial relationship information may include information such as in table 35 below.

TABLE 35

Referring to the sputialrationinfo configuration, the SS/PBCH block index, the CSI-RS index, or the SRS index may be configured as an index of a reference signal referenced as beam information using a specific reference signal. The upper layer signaling reference signal is configuration information indicating reference signal beam information to be referred to for SRS transmission, ssb-Index is an Index of SS/PBCH block, CSI-RS-Index is an Index of CSI-RS, and SRS is an Index of SRS. If the value of the upper layer signaling reference signal is set to "ssb-Index", the UE may apply a reception beam used when receiving the SS/PBCH block corresponding to the ssb-Index as a transmission beam of the corresponding SRS transmission. If the value of the upper layer signaling reference signal is set to "CSI-RS-Index", the UE may apply a reception beam used when receiving the CSI-RS block corresponding to the CSI-RS-Index as a transmission beam of the corresponding SRS transmission. If the value of the upper layer signaling reference signal is set to "SRS", the UE may apply a transmission beam used when transmitting SRS the corresponding SRS as a transmission beam for the corresponding SRS transmission.

[ PUSCH: related to transmission of transmissions

Next, a scheduling method of PUSCH transmission will be described. PUSCH transmissions may be dynamically scheduled by UL grants in DCI, or may be operated by configured grant type 1 or type 2. The dynamic scheduling indication of PUSCH transmission may be implemented by DCI format 0_0 or 0_1.

The configured grant type 1PUSCH transmission may be semi-statically configured by receiving a configurable grant including the rrc-configurable uplink grant of table 36, without receiving a UL grant in the DCI, through upper signaling. The configured grant type 2PUSCH transmission may be semi-continuously scheduled via UL grants in the DCI after receiving the configurable grant that does not include the rrc-configurable uplink grant of table 36. When the PUSCH transmission is operated by the configured grant, the parameters applied to the PUSCH transmission are applied through the upper layer signaling configurable grantconfig of table 36, except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank in table 37 and the scaling of the upper layer signaling PUSCH-Config providing UCI-on PUSCH. If the UE provides a transformpre-coder in the upper layer signaling configuration grant in table 36, the UE applies tp-pi2BPSK in the PUSCH-Config of table 37 to PUSCH transmission operated by the configured grant.

TABLE 36

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Next, a PUSCH transmission method will be described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmissions may follow a codebook-based transmission method and a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in the higher signaling PUSCH-Config of table 37 is "codebook" or "non codebook".

As described above, PUSCH transmissions may be dynamically scheduled by DCI formats 0_0 or 0_1, and may be semi-statically configured by a configured grant. If the UE is instructed to schedule PUSCH transmission with DCI format 0_0, the UE will perform beam setup for PUSCH transmission using the puch-sputlrelationinfoid corresponding to the UE-specific PUCCH resource corresponding to the minimum ID in the activated uplink BWP in the serving cell, and in this case, PUSCH transmission is based on a single antenna port. The UE does not expect PUSCH transmission to be scheduled through DCI format 0_0 in BWP that does not configure PUCCH resources including PUCCH-sputterrelation info. If the UE has not received txConfig configured in the pusch-Config of table 37, the UE does not expect to schedule using DCI format 0_1.

TABLE 37

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Next, a codebook-based PUSCH transmission will be described. Codebook-based PUSCH transmissions may be dynamically scheduled by DCI formats 0_0 or 0_1 and semi-statically operated by configured grants. When codebook-based PUSCH is dynamically scheduled by DCI format 0_1 or semi-statically configured by configured grants, the UE determines a precoder for PUSCH transmission based on SRS Resource Indicator (SRI), transmission Precoding Matrix Indicator (TPMI), and transmission rank (PUSCH transmission layer number).

In this case, the SRI may be given by a field SRS resource indicator in the DCI, or may be configured by upper layer signaling SRS-Resourceindicator. When transmitting codebook-based PUSCH, the UE may receive at least one configured SRS resource and at most two configured SRS resources. When the SRI is provided to the UE through DCI, the SRS resource indicated by the corresponding SRI refers to an SRS resource corresponding to the SRI among SRS resources transmitted before the PDCCH including the corresponding SRI. In addition, TPMI and transmission rank may be given by field precoding information and the number of layers in DCI, or may be configured by upper layer signaling precoding and reporting layers. TPMI is used to indicate the precoder applied to PUSCH transmission. If the UE receives one of the configured SRS resources, TPMI is used to indicate a precoder to be applied in the one of the configured SRS resources. If the UE receives the configured plurality of SRS resources, TPMI is used to indicate a precoder to be applied in the SRS resources indicated through the SRI.

The precoder for PUSCH transmission is selected from the uplink codebook with the same number of antenna Ports as the nrofSRS-Ports value in the upper layer signaling SRS-Config. In codebook-based PUSCH transmission, the UE determines a codebook subset based on TPMI and codebook subset in the upper layer signaling push-Configuration. The codebook subset in push-Config is upper layer signaling that can be configured as one of "fullypartialanddnoncoder", "partialanddnoncoder" or "non-coder" based on UE capabilities reported by the UE to the base station. If the UE reports "partialAndNON Coherent" as UE capability, the UE does not expect the higher layer signaling codebook subset value to be configured as "fullyParafialAndNON Coherent". Furthermore, if the UE reports "non-peer" as UE capability, the UE does not expect the value of the higher layer signaling codebook subset to be configured as "fullyand partialanddnonpeer" or "partialanddnonpeer". When nrofSRS-Ports in the upper layer signaling SRS-resource (indicating two SRS antenna Ports), the UE does not expect to configure the value of the upper layer signaling codebook subset to "partialanddnonparty".

The UE may receive one SRS Resource Set in which the use case value in the upper layer signaling SRS-Resource Set is configured as "codebook", and one SRS Resource in the SRS Resource Set may be indicated by the SRI. If multiple SRS resources are configured in the SRS Resource Set, where the use case value in the upper layer signaling SRS-Resource Set is configured as "codebook", the UE expects that the nrofSRS port value in the upper layer signaling SRS-Resource is configured to be the same for all SRS resources.

The UE transmits one or more SRS resources included in the SRS resource set whose use case value is configured as "codebook" to the base station according to the upper layer signaling, and the base station selects one of the SRS resources transmitted by the UE and instructs the UE to perform PUSCH transmission using transmission beam information of the corresponding SRS resource. In this case, in the codebook-based PUSCH transmission, SRI is used as information of an index selecting one SRS resource and is included in DCI. In addition, the base station further includes information indicating TPMI and rank of the UE for PUSCH transmission in DCI. The UE performs PUSCH transmission by applying the indicated rank and the TPMI indicated precoder based on the transmission beam of the corresponding SRS resource using the SRS resource indicated by the SRI.

Next, a non-codebook-based PUSCH transmission will be described. Non-codebook-based PUSCH transmissions may be dynamically scheduled by DCI formats 0_0 or 0_1 and semi-static operation may be performed by configured grants. When at least one SRS resource is configured in the SRS resource set with the use case value configured as "non codebook" in the upper layer signaling SRS-resource set, the UE may receive the non-codebook-based PUSCH transmission scheduled through DCI format 0_1.

For SRS resource sets in which the use case value in the upper layer signaling SRS-resource is configured as "non codebook", the UE may receive one configured connected non-zero power CSI-RS (NZP CSI-RS resource). The UE may perform calculations on a precoder of SRS transmissions by measuring NZP CSI-RS resources 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 the aperiodic SRS transmission in the UE is less than 42 symbols, the UE does not expect to update information about the SRS transmission precoder.

When the resource type value in the upper layer signaling SRS-resource set is configured as "adaptive", the connected NZP CSI-RS is indicated by an SRS request, where the SRS request is a field of DCI format 0_1 or 1_1. In this case, if the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, it indicates that the connected NZP CSI-RS exists when the value of the field SRS request of the DCI format 0_1 or 1_1 is not "00". In this case, the corresponding DCI may not indicate cross-carrier or cross-BWP scheduling. Further, if the value of the SRS request indicates that there is an NZP CSI-RS, the corresponding NZP CSI-RS is located in a slot in which a PDCCH including an SRS request field is transmitted. In this case, the TCI state configured in the scheduled subcarrier is not set to QCL-type.

If configured with a periodic or semi-persistent SRS resource set, the connected NZP CSI-RS may be indicated by an associated CSI-RS in an upper layer signaling SRS-resource set. For non-codebook based transmissions, the UE does not expect to configure the sputialreactioninfo as upper layer signaling of SRS resources with the associated CSI-RS in the upper layer signaling SRS-resource.

When configuring the plurality of SRS resources, the UE may determine a precoder and a transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. In this case, the SRI may be indicated by a field SRS resource indicator in the DCI, or may be configured by upper layer signaling SRS-Resourceindicator. Similar to the codebook-based PUSCH transmission described above, when the UE receives the SRI through the DCI, the SRS resource indicated by the corresponding SRI refers to an SRS resource corresponding to the SRI among SRS resources transmitted before the PDCCH including the corresponding SRI. The UE may use one or more SRS resources for SRS transmission and the maximum number of SRS resources that can be transmitted simultaneously with the same symbol in one SRS resource set is determined by the UE capability reported by the UE to the base station. In this case, SRS resources simultaneously transmitted by the UE occupy the same RB. The UE configures one SRS port for each SRS resource. Only one SRS resource set of usage values of the upper layer signaling SRS-resource set is configured as "non codebook", and up to four SRS resources may be configured for non-codebook based PUSCH transmission.

The base station transmits one NZP-CSI-RS connected to the SRS resource set to the UE, and the UE calculates a precoder to be used when transmitting one or more SRS resources in the corresponding SRS resource set based on a result measured when receiving the corresponding NZP-CSI-RS. The UE applies the calculated precoder when transmitting one or more SRS resources of the SRS resource set whose use case value is set to "non-codebook" to 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 a PUSCH transmission that is not codebook-based, the SRI indicates an index capable of representing one SRS resource or a combination of a plurality of 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 may be the number of transmission layers of the PUSCH, and the UE transmits the PUSCH by applying a precoder applied to SRS resource transmission to each layer.

[ PUSCH: preparation procedure time ]

Next, PUSCH preparation procedure time will be described. When the base station schedules the UE to transmit PUSCH using DCI format 0_0, 0_1 or 0_2, the UE may need PUSCH preparation procedure time to transmit PUSCH by applying a transmission method (SRS resource transmission precoding method, transmission layer number and spatial domain transmission filter) indicated by DCI. In NR, PUSCH preparation procedure time is defined in consideration of this point. The PUSCH preparation procedure time of the UE may follow the following equation 4.

[ equation 4]

T _proc，2 ＝max((N ₂ +d _2，1 +d ₂ )(2048+144) _κ 2 ^-μ T _c +T _ext +T _switch ，d _2,2 )。

Each variable in Tproc,2 described in equation 4 above may have the following meaning:

-N2: the number of symbols determined according to the UE processing function 1 or 2 and the parameter set μ determined according to the function of the UE. N2 may have values in table 38 when reported as UE processing function 1 according to a function report of the UE, and may have values in table 39 when reported as UE processing function 2 according to a function report of the UE and configured by upper layer signaling that may use UE processing function 2.

TABLE 38

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TABLE 39

μ	PUSCH preparation time N ₂ [ symbol ]]
		0	5
1	5.5
		2	11 for frequency range 1

-d2,1: when all resource elements of the first OFDM symbol of the PUSCH transmission are configured to consist of DM-RS only, the number of symbols is set to 0, otherwise to 1; -K:64;

- μ: following Tproc,2 at μ _DL And mu _UL Is larger in value. Mu (mu) _DL A parameter set of downlink to which a PDCCH including DCI scheduling PUSCH is transmitted, and μ _UL A parameter set of an uplink to which a PUSCH is transmitted;

tc having 1/(. DELTA.f) _max ·N _f )、△f _max ＝480·10 ³ Hz and N _f ＝4096；

-d2,2: when the DCI of the scheduled PUSCH indicates BWP switching, the BWP switching time is followed, otherwise 0;

-d2: when the PUCCH and PUSCH with high priority index and the OFDM symbol of the PUCCH with low priority index overlap in time, the d2 value of PUSCH with high priority index will be used. Otherwise, d2 is 0;

Text: when the UE uses the shared spectrum channel access method, the UE may calculate "Text" and apply the "Text" to the PUSCH preparation procedure time. Otherwise, assume "Text" is 0; and is also provided with

Tswitch: when the uplink switching interval is triggered, tswitch is assumed to be the switching interval time. Otherwise, assume 0.

Considering the influence of the time axis resource mapping information of the PUSCH scheduled by the DCI and the timing advance between uplink and downlink, if the first symbol of the PUSCH starts after Tproc,2, which is the last symbol of the PDCCH including the DCI scheduling the PUSCH, the base station and the UE determine that the PUSCH preparation procedure time is insufficient. Otherwise, the base station and the UE determine that PUSCH preparation procedure time is sufficient. The UE can only transmit PUSCH when PUSCH preparation procedure time is sufficient, and ignore DCI scheduling PUSCH when PUSCH preparation procedure time is insufficient.

[ PUSCH: related to repeated transmissions

The retransmission of the uplink data channel in the 5G system will be described in detail below. The 5G system supports two repeated transmission modes of an uplink data channel, namely a PUSCH repeated transmission A type and a PUSCH repeated transmission B type. The UE may receive one of PUSCH retransmission types a or B configured by upper layer signaling.

PUSCH repeat Transmission type A

As described above, the symbol length and the starting symbol position of the uplink data channel are determined within one slot via the time domain resource allocation method, and the base station may inform the UE of the number of repeated transmissions through upper layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI).

The UE may repeatedly transmit the uplink data channel in consecutive slots based on the number of repeated transmissions received from the base station, wherein the length of the configured uplink data channel is the same as the starting symbol. In this case, when at least one or more symbols in a slot configured as a downlink by the base station to the UE are configured as a downlink, or symbols of a configured uplink data channel received by the UE. The UE omits uplink data channel transmission but counts the number of repeated transmissions of the uplink data channel.

PUSCH repeat Transmission type B

As described above, the start symbol and length of the uplink data channel are determined within one slot via the time domain resource allocation method, and the base station may inform the UE of the number of times of repeated transmission by upper layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI).

First, the nominal number of repetitions of the uplink data channel is determined based on the start symbol and length of the configured uplink data channel as follows. The time slot of the nth nominal repetition is started by Given, and the symbol starting from this time slot is made of +.>Given. The nth nominal repetition terminated time slot is defined byThe symbol given and ending from the slot is made of +.>Given. Here, n=0,..and number of repetitions-1, and S represents a start symbol of the configured uplink data channel, and L represents a symbol length of the configured uplink data channel. K (K) _s Time slot representing the start of PUSCH transmission, and +.>Representing the number of symbols per slot.

The UE determines an invalid symbol of PUSCH repetition transmission type B. The invalid symbol for PUSCH repetition transmission type B is determined by tdd-UL-DL-configuration common or tdd-UL-DL-configuration dedicatedly. In addition, an invalid symbol may be configured in an upper layer parameter (e.g., invalidSymbolPattern). The upper layer parameters (e.g., invalidSymbolPattern) may provide symbol level bitmaps on one or both slots so that invalid symbols may be configured. In the bitmap, 1 represents an invalid symbol. Further, the period and pattern of the bitmap may be configured by an upper layer parameter (e.g., periodicityAndPattern). If an upper layer parameter (e.g., invalidSymbolPattern) is configured and either InvalidSymbolPattern indicator-ForDCIFORAT0_1 or InvalidSymbolPattern indicator-ForDCIFORAT0_2 parameter indicates 1, then the UE applies the invalid symbol mode and if the parameter indicates 0, then the UE does not apply the invalid symbol mode. If an upper layer parameter (e.g., invalidSymbolPattern) is configured and either the InvalidSymbolPattern indicator-ForDCIFormat0_1 or the InvalidSymbolPattern indicator-ForDCIFormat0_2 parameter is not configured, then the UE will apply the invalid symbol pattern.

After determining the invalid symbols, the UE may consider symbols other than the invalid symbols as valid symbols for each nominal repetition. If one or more valid symbols are included in each nominal repetition, the nominal repetition may include one or more actual repetitions. Here, each actual repetition includes a set of consecutive valid symbols of PUSCH repetition transmission type B available in one slot.

Fig. 17 illustrates an example of a B-type repeated PUSCH transmission in a wireless communication system according to one embodiment of the present disclosure. The start symbol S, which the UE can receive the uplink data channel, is set to 0, the length L of the uplink data channel is set to 14, and the number of repeated transmissions is set to 16. In this case, a nominal repetition is indicated in 16 consecutive time slots 1701. Thereafter, the UE may determine that the symbol configured as the downlink in each normal repetition 1701 is an invalid symbol. Further, the UE determines a symbol set to 1 in the invalid symbol pattern 1702 as an invalid symbol. When the active symbols other than the inactive symbol in each nominal repetition consist of one or more consecutive symbols in a slot, the symbols are configured to actually repeat and transmit 1703.

Furthermore, for PUSCH repetition transmission, NR release 16 may define the following additional methods for UL grant based PUSCH transmission outside the slot boundary and configured grant based PUSCH transmission.

In one example of method 1 (small slot level repetition), two or more PUSCH repetition transmissions are scheduled within a slot or outside the boundary of consecutive slots with one UL grant. Further, for method 1, the time domain resource allocation information in the dci indicates resources of the first retransmission. Further, the time domain resource information of the first retransmission and the time domain resource information of the remaining retransmissions may be determined according to an uplink or downlink direction determined per symbol of each slot. Each repeated transmission occupies consecutive symbols.

In one example of method 2 (multi-segment transmission), two or more PUSCH repeated transmissions are scheduled within consecutive slots with one UL grant. In this case, one transmission is designated for each slot, and the start point or repetition length of each transmission may be different. Further, for method 2, the time domain resource allocation information in the dci indicates the start point and repetition length of all repeated transmissions. Furthermore, in the case of repeated transmission in a single slot by the method 2, if there are a plurality of consecutive uplink symbol bundles in the corresponding slot, each repeated transmission is performed for each uplink symbol bundle. If there is only one contiguous uplink symbol bundle in the corresponding slot, one PUSCH repetition transmission is performed according to the NR release 15 method.

In one example of method 3, two or more PUSCH repeated transmissions are scheduled within consecutive slots with two or more UL grants. In this case, one transmission is specified for each slot, and the nth UL grant may be received before the scheduled PUSCH transmission with the nth-1 UL grant ends.

In one example of method 4, repeated transmission of one or more PUSCHs within a single slot, or repeated transmission of two or more PUSCHs across consecutive slot boundaries, may be supported by one UL grant or one configuration grant. The number of repetitions indicated by the base station to the UE is only a nominal value, and the number of repeated PUSCH transmissions actually performed by the UE may be greater than the nominal number of repetitions. The time domain resource allocation information in the DCI or configuration grant refers to the resources of the first retransmission indicated by the base station. The time domain resource information of the remaining retransmissions may be determined at least with reference to the resource information of the first retransmission and the uplink or downlink direction of the symbol. If the time domain resource information of the retransmission indicated by the base station crosses a slot boundary or includes an uplink/downlink switching point, the retransmission may be divided into a plurality of retransmissions. In this case, each uplink period in one slot may include one repeated transmission.

[ PUSCH: frequency hopping procedure ]

Frequency hopping of a Physical Uplink Shared Channel (PUSCH) in the 5G system will be described in detail.

In 5G, as a frequency hopping scheme of the uplink data channel, each PUSCH repetition transmission type supports two schemes. First, PUSCH retransmission type a supports intra-slot frequency hopping and inter-slot frequency hopping, and PUSCH retransmission type B supports repeated frequency hopping and inter-slot frequency hopping.

The intra-slot frequency hopping method supported by PUSCH retransmission type a is a method in which a UE changes and transmits frequency domain allocation resources by a frequency offset configured in two hops within one slot. In intra-slot hopping, the starting RB of each hop can be expressed by the following equation 4.

[ equation 4]

In equation 4, i=0 and i=1 represent the first hop and the second hop, respectively, and RB _start The starting RB in UL BWP is represented and calculated by a frequency resource allocation method. RB (radio bearer) _offset Representing the frequency offset between two hops through the upper layer parameters. The number of symbols of the first hop can be usedRepresenting, and the number of symbols of the second hop can be usedAnd (3) representing. />Is the length of PUSCH transmission within one slot and is expressed as the number of OFDM symbols.

Second, the inter-slot frequency hopping method supported by the repeated PUSCH transmission types a and B is a method in which the UE changes and transmits frequency domain allocated resources of each slot through a configured frequency offset. In inter-slot frequency hopping, slots The initial RB of the period can be expressed by equation 5. />

[ equation 5]

In the equation 5 of the present application,representing the current number of slots in a multislot PUSCH transmission, and RB _start The starting RB in UL BWP is represented and calculated by a frequency resource allocation method. RN (RN) _offset Representing the frequency offset between two hops through the upper layer parameters.

Second, the method of hopping between repetitions supported by the repetition PUSCH transmission type B is to move and transmit resources for one or more actual repetitions within each nominal repetition in the frequency domain by means of a configured frequency offset. RBstart (n) is an index of the starting RB in the frequency domain of one or more actual repetitions in the nth nominal repetition, and may follow equation 6 below.

[ equation 6]

In equation 6, n represents the labelRepeat index is called and RB _offset Representing the RB offset between two hops through the upper layer parameters.

[ PUSCH: multiplexing rules when AP/SP CSI reporting

A method of measuring and reporting a channel state in a 5G communication system will be described in detail hereinafter. The Channel State Information (CSI) may include Channel Quality Information (CQI), a Precoding Matrix Indicator (PMI), a CSI-RS resource indicator (CRI), an SS/PBCH block resource indicator (SSBRI), a Layer Indicator (LI), a Rank Indicator (RI), and/or L1-Reference Signal Received Power (RSRP). The base station may control the time and frequency resources for the above CSI measurement and reporting of the UE.

For the above-described CSI measurement and reporting, the UE may receive setting information (CSI-ReportConfig) on N (Σ1) CSI reports, setting information (CSI-ResourceConfig) on M (Σ1) RS transmission resources, one or two trigger state (CSI-AperiodicTriggerStateList, CSI-semipersistent on pusch-TriggerStateList) list information through upper layer signaling. Configuration information regarding the above CSI measurement and reporting may be more specifically described in the following tables 40 to 46.

Table 40 csi-ReportConfig:

TABLE 40

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TABLE 41 CSI-ResourceConfig TABLE 41

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Table 42 NZP-CSI-RS-ResourceSet Table 42

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TABLE 43 CSI-SSB-ResourceSet TABLE 43

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Table 44 CSI-IM-ResourceNet Table 44

TABLE 45 CSI-AperiodicTriggerStateList TABLE 45

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TABLE 46 CSI-semiPersistentOnPUSCH-TriggerStateList

TABLE 46

Regarding the above-described CSI reporting settings (CSI-ReportConfig), each reporting setting CSI-ReportConfig may be associated with a CSI resource setting associated with the corresponding reporting setting, and one Downlink (DL) bandwidth portion identified by an upper layer parameter bandwidth portion identifier (bwp-id) given by CSI-ResourceConfig. As a time domain reporting operation of setting CSI-ReportConfig per report, "reporting" (aperiodic), "semi-persistent" (semi-persistent) and "periodic" methods are supported, and this can be configured from the base station to the UE through reportConfigType parameters configured from an upper layer. The semi-persistent CSI reporting method supports "PUCCH-based semi-persistent (semi-persistent on PUCCH)" and "PUSCH-based semi-persistent (semi-persistent on PUSCH)". In case of the periodic or semi-persistent CSI reporting method, the UE may receive the configured PUCCH or PUSCH resources for transmitting CSI from the base station through upper layer signaling. The periodicity and slot offset of PUCCH or PUSCH resources for transmitting CSI may be as a set of parameters for an Uplink (UL) bandwidth portion configured to transmit CSI reports. In case of the aperiodic CSI reporting method, the UE may receive scheduled PUSCH resources for transmitting CSI from the base station through L1 signaling (DCI format 0_1 described above).

Regarding the above-described CSI resource settings (CSI-ResourceConfig), each CSI resource setting CSI-ReportConfig may include S (. Gtoreq.1) sets of CSI resources (given as upper layer parameters CSI-RS-ResourceLetList). The CSI resource set list may be composed of a non-zero power consumption (NZP) CSI-RS resource set and an SS/PBCH block set, or may be composed of a CSI interference measurement (CSI-IM) resource set. Each CSI resource setting may be located in a Downlink (DL) bandwidth portion identified by an upper layer parameter bwp-id, and the CSI resource setting may be connected to a CSI report setting of the same downlink bandwidth portion. The time domain operation of the CSI-RS resources in the CSI resource setting may be configured as one of an "aperiodic" CSI resource configuration, a "periodic" CSI resource configuration, or a "semi-persistent" CSI resource configuration from the upper layer parameter resourceType. For periodic or semi-persistent CSI resource settings, the number of CSI-RS resource sets may be limited to s=1, and the configured period and slot offset may be given as a set of parameters for the downlink bandwidth portion identified by bwp-id.

The UE may receive one or more CSI resource settings for channel or interference measurement from the base station through upper layer signaling and may include, for example, the following CSI resources.

-CSI-IM resources for interference measurement;

-NZP CSI-RS resources for interference measurement; and

NZP CSI-RS resources for channel measurement.

For a set of CSI-RS resources associated with a resource setting configured as "aperiodic", "periodic", or "semi-persistent" for an upper layer parameter resource type, a trigger state for a CSI report setting with a reportType set as "aperiodic", and a resource setting for channel or interference measurements for one or more component units (CCs) may be configured as an upper layer parameter CSI-apiodictriggerstatelist.

Aperiodic CSI reporting of the UE may be performed using PUSCH, periodic CSI reporting of the UE may be performed using PUCCH, semi-persistent CSI reporting of the UE may be performed using PUSCH when triggered or activated using DCI, and may be performed using PUCCH after activated using MAC control element (MAC CE). As described above, CSI resource settings may also be configured aperiodically, periodically, or semi-permanently. Based on the following table 47, a combination between CSI reporting settings and CSI resource configurations may be supported.

Table 47 table 5.2.1.4-1: CSI reporting of possible CSI-RS configurations is triggered/activated.

TABLE 47

Table 5.2.1.4-1: CSI reporting of possible CSI-RS configurations is triggered/activated.

Aperiodic CSI reporting may be triggered by the "CSI request" field of DCI format 0_1 described above, which corresponds to the scheduled DCI of PUSCH. The UE may monitor the PDCCH and acquire DCI format 0_1, scheduling information on PUSCH, and a CSI request indicator. The CSI request indicator may be configured as NTS (=0, 1, 2, 3, 4, 5, or 6) bits and may be determined by upper layer signaling (reportTriggerSize). One of the one or more aperiodic CSI report trigger states may be configured as upper layer signaling (CSI-aperiodic triggerstatelist) that may be triggered by a CSI request indicator.

In one example, when all bit values of the CSI request field are 0, it may mean that no CSI report is requested.

In one example, if the number of CSI trigger states (M) in the configured CSI-apeeriodicttriggerstatelist is greater than 2NTS-1, then M CSI trigger states may be mapped to 2NTS-1 according to a predefined mapping relationship, and one of the trigger states of 2NTS-1 may be indicated by a CSI request field.

In one example, if the number of CSI trigger states (M) in the configured CSI-apeeriodicttriggerstatelist is less than or equal to 2NTS-1, one of the M CSI trigger states may be indicated by a CSI request field.

Table 48 below shows an example of a relationship between CSI request indicators and CSI triggered states that may be indicated by the corresponding indicators.

TABLE 48

The UE may perform measurements on CSI resources in a CSI triggered state triggered by the CSI request field and thereby generate CSI (including at least one of CQI, PMI, CRI, SSBRI, LI, RI or L1-RSRP). The UE may transmit the obtained CSI using PUSCH scheduled by the corresponding DCI format 0_1. When one bit corresponding to the uplink data indicator (UL-SCH indicator) of DCI format 0_1 indicates "1", uplink data (UL-SCH) and the obtained CSI may be multiplexed and transmitted to PUSCH resources scheduled by DCI format 0_1. When one bit corresponding to the uplink data indicator (UL-SCH indicator) of DCI format 0_1 indicates "0", only CSI containing no uplink data (UL-SCH) may be mapped and transmitted to PUSCH resources scheduled by DCI format 0_1. Fig. 13 shows an example according to an aperiodic CSI reporting method.

In the example shown in fig. 13, the UE may monitor PDCCH 1301 to obtain DCI format 0_1 and may obtain scheduling information and CSI request information on PUSCH 1305 therefrom. The UE may obtain resource information about the CSI-RS1302 to be measured from the received CSI request indicator. The UE may determine the time at which the UE may perform measurements on the transmitted CSI-RS1302 resources based on the time at which DCI format 0_1 is received and parameters (the above-described apeeriodictriggering offset) offset in the CSI resource set configuration (e.g., NZP CSI-RS-resource set configuration). More specifically, the UE may receive an offset value X of a parameter aperiodic triggeringoffset in NSQP-CSI-RS resource set configuration through upper layer signaling from the base station, and the configured offset value X may refer to an offset between a slot in which the reception DCI triggers the aperiodic CSI report and a slot in which the CSI-RS resource is transmitted. For example, the apiodicTriggeringOffset parameter value and the offset value X may have a mapping relationship described in Table 49 below.

TABLE 49

aperiodicTriggeringOffset	Offset X
		0	0 time slots
1	1 time slot
		2	2 time slots
3	3 time slots
		4	4 time slots
5	16 time slots
		6	24 time slots

The example in fig. 13 shows an example in which the above-described offset value is set to x=0. In this case, the UE may receive the CSI-RS1302 in a slot (corresponding to slot 0 1306 in fig. 13) in which the DCI format 0_1 is received to trigger the aperiodic CSI report, and may report CSI information measured by the received CSI-RS to the base station through the PUSCH 1305. The UE may acquire scheduling information of PUSCH 1305 for CSI report (the above information corresponding to each field in DCI format 0_1) from DCI format 0_1. For example, in DCI format 0_1, the UE may acquire information on a slot in which PUSCH 1305 is transmitted from time domain resource allocation information on PUSCH 1305. In the example in fig. 13, the UE obtains a K2 value of 3 corresponding to a PDCCH-to-PUSCH slot offset value, and accordingly, PUSCH 1305 may be transmitted in slot 3 1309 three slots away from slot 0 1306, and PUSCH 1305 receives PDCCH 1301 in that slot. In the example in fig. 13, the UE may acquire DCI format 0_1 by monitoring PDCCH 1311 and may acquire scheduling information and CSI request information about PUSCH 1315 therefrom. The UE may obtain resource information about CSI-RS1312 to be measured from the received CSI request indicator. An example in which the offset value of the CSI-RS described above is set to x=1 is shown in the example of fig. 13. In this case, the UE may receive the CSI-RS1312 in a slot (corresponding to slot 0 1316 in fig. 13) in which the DCI format 0_1 is received to trigger the aperiodic CSI report, and may report CSI information measured by the received CSI-RS to the base station through the PUSCH 1315.

The aperiodic CSI report may include at least one or both of CSI part 1 and part 2, and the aperiodic CSI report may be multiplexed with the transport block when the aperiodic CSI report is transmitted through the PUSCH. After inserting the CRC into the input bits of the aperiodic CSI for multiplexing, the aperiodic CSI report may be mapped to the resource elements in the PUSCH in a specific pattern and transmitted after being encoded and rate-matched. CRC insertion may be omitted depending on the encoding method or the length of the input bits. When multiplexing CSI part 1 or CSI part 2 included in the aperiodic CSI report, the number of modulation symbols calculated for rate matching may be calculated as shown in table 50 below.

TABLE 50]

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Specifically, in the case of the repeated PUSCH transmission schemes a and B, the UE may transmit the aperiodic CSI report by multiplexing only the first repeated PUSCH transmission in the repeated PUSCH transmissions.

This is because multiplexed aperiodic CSI report information is encoded in a polarization code scheme, and in this case, in order to be multiplexed to a plurality of PUSCH repetitions, each PUSCH repetition may have the same frequency and time resource allocation, and in particular, in the case of PUSCH repetition type B, since each actual repetition may have a different OFDM symbol length, the aperiodic CSI report may be multiplexed and transmitted only for the first PUSCH repetition.

Further, for PUSCH retransmission type B, when the UE schedules an aperiodic CSI report without scheduling a transport block or receiving DCI to activate a semi-persistent CSI report, even though the number of PUSCH retransmissions configured by upper layer signaling is greater than 1, a scalar complex value of 1 may be assumed. Further, the UE may expect the first nominal repetition to be equal to the first actual repetition when the UE schedules or activates aperiodic or semi-persistent CSI reports without scheduling transport blocks based on PUSCH repetition transmission type B. For PUSCH repetition transmission type B based on, but without, the DCI scheduled following activation of the semi-persistent CSI report using DCI, the transmission of the first nominal repetition may be ignored if the first nominal repetition is different from the first actual repetition.

[ related to UE capability reporting ]

In LTE and NR, a UE may perform a procedure of reporting functions supported by the UE to a corresponding base station while being connected to a serving base station. In the following description, this is referred to as UE capability reporting.

The base station may transmit a UE-capable function query message to the UE in a connected state, thereby requesting a function report. The message may include a UE capability request for each Radio Access Technology (RAT) type of the base station. The request for each RAT type may include supported band combination information, etc. Further, in the case of the UE capability query message, the UE capability for each RAT type may be requested through one RRC message container transmitted by the base station, or the base station may include the UE capability query message including a plurality of UE capability requests for each RAT type and transmitting the UE capability query message to the UE. That is, the UE capability query may be repeated multiple times in one message, and the UE may configure and report the corresponding UE capability information message multiple times. In the next generation mobile communication system, a UE capability request of NR, LTE, EN-DC (E-UTRA-NR dual connectivity) and MR-DC (Multi-RAT dual connectivity) may be requested. Further, the UE capability query message is typically initially sent after the UE connects to the base station, but may be requested under any condition requiring the base station.

In the above steps, the UE receiving the UE capability report request from the base station may configure the UE capability according to RAT type and band information requested from the base station. The following summarizes the method for configuring the UE capability of the UE in the NR system

In one example, if the UE is provided with a list of LTE and/or NR bands through a UE capability request of the base station, the UE may configure a Band Combination (BC) for EN-DC and NR independent (SA). That is, the UE may configure BC candidate lists for EN-DC and NR SA based on the frequency band requested by the base station through FreqBandList. Further, the priority of the frequency bands may have priority in the order described in FreqBandList.

In one example, if the base station requests the UE capability report by setting the "eutra-NR-only" flag or the "eutra" flag, the UE will completely delete the content about the NR SA BC from the BC candidate list configured above. This occurs only when the LTE base station (eNB) requests the "eutra" function.

In one example, the UE may thereafter delete the fallback BC from the BC candidate list configured in the above steps. The fallback BC refers to BC obtained by removing a frequency band corresponding to at least one SCell from any BC, and may be omitted because BC may already cover fallback BC before removing the frequency band corresponding to at least one SCell. This step can also be applied to MR-DC, and also to LTE bands. The BC remaining after this step is the final "candidate BC list".

In one example, the UE may select the BC to report by selecting the BC corresponding to the requested RAT type from the above "final candidate BC list". In this step, the UE configures supplementadband communication list in a fixed order. That is, the UE configures BC and UE capabilities to be reported according to a predetermined RAT-Type order (nr- > eutra-nr- > eutra). Further, the UE configures featureset combination for the configured suppleddband combination list, and configures a "candidate feature set combination" list from which the fallback BC list (including the same or lower level functions) has been removed from the candidate BC list. The "candidate function set combinations" described above may include feature set combinations of NR and EUTRA-NR BC, and may be obtained from feature set combinations of UE-NR-Capabilities and UE-MRDC-Capabilities containers.

Furthermore, in one example, if the requested RAT type is eutra-NR and is affected, the featurecodes may be included in two UE-MRDC-Capabilities and UE-NR-Capabilities containers. However, the NR functionality set may be included only in the UE-NR-Capabilities.

After configuring the UE capabilities, the UE sends a UE capability information message including the UE capabilities to the base station. The base station performs scheduling and transmission/reception management on the UE based on the UE capability information received from the UE.

[ CA/DC-related ]

Fig. 18 illustrates a radio protocol structure of a base station and a UE in single cell, carrier aggregation, and dual connectivity scenarios in accordance with one embodiment of the present disclosure.

Referring to fig. 18, the radio protocols of the next generation mobile communication system include service data adaptation protocols (NR SDAP) S25 and S70, packet data convergence protocols (NR PDCP) S30 and S65, radio RLC link control (NR RLC) S35 and S60, and medium access control (NR MAC) S40 and S55 in the UE and the NR base station, respectively.

The main functions of NR SDAP S25 and S70 may include part of the following functions:

-transmission of user plane data;

-mapping between QoS flows and DRBs for both DL and UL;

-marking QoS flow IDs in both DL and UL packets; and

-a reflected QoS flow to DRB mapping for UL SDAP PDUs.

Regarding the SDAP layer device, as the RRC message, the UE may configure whether to use a header of the SDAP layer device for each PDCP layer device, bearer, or logical channel, or to use a function of the SDAP layer device for each bearer or each logical channel. When configuring the SDAP header, the base station may instruct the UE to update or reconfigure mapping information for uplink and downlink QoS flows and data bearers, wherein a NAS QoS reflection setting 1-bit indicator (NAS reflection QoS) and an AS QoS reflection setting 1-bit indicator (AS reflection QoS) are included in the SDAP header. The SDAP header can include QoS flow ID information indicating QoS. QoS information may be used as data processing priority and scheduling information to support smooth service.

The main functions of NR PDCP S30 and S65 may include part of the following functions:

header compression and decompression (ROHC only);

-user data transfer;

-in-order transmission of upper layer PDUs;

out-of-order delivery of upper layer PDUs;

-reordering of PDCP PDUs for reception;

-duplicate detection of lower layer SDUs;

retransmission of PDCP SDUs;

-encryption and decryption; and

-timer based SDU discard in uplink.

In the above description, the reordering function of NR PDCP refers to a function of reordering PDCP PDUs received from a lower layer based on a PDCP Sequence Number (SN), and may include a function of transmitting data to an upper layer in a reordered order. Further, the reordering function of NR PDCP may include a function of directly transmitting irrespective of the order, may include a function of reordering this order to record lost PDCP PDUs, may include a function of reporting a status of lost PDCP PDUs to a transmitting side, or may include a function of requesting retransmission of lost PDCP PDUs.

The main functions of NR RLC S35, S60 may include part of the following functions:

-transmission of upper layer PDUs;

-in-order transmission of upper layer PDUs;

out-of-order delivery of upper layer PDUs;

-error correction by ARQ;

concatenation, segmentation and reassembly of RLC SDUs;

-re-segmentation of RLC data PDUs;

-reordering of RLC data PDUs;

-repeated detection;

-protocol error detection;

-RLC SDU discard; and

RLC re-establishment.

In the above, the in-order transfer of the NR RLC device refers to a function of sequentially transferring RLC SDUs received from a lower layer to an upper layer. The in-order delivery of the NR RLC device may include a function of reassembling and delivering when an RLC SDU is initially divided into several RLC SDUs and received, may include a function of rearranging received RLC PDUs based on RLC Sequence Numbers (SNs) or PDCP Sequence Numbers (SNs), may include a function of rearranging the order in which missing RLC PDUs are recorded, may include a function of performing status reporting of the missing RLC PDUs on a transmitting side, may include a function of requesting retransmission of the missing RLC PDUs. The in-order transfer of the NR RLC device may include a function of sequentially transferring RLC SDUs to an upper layer only before RLC SDUs are lost when there is a missing RLC SDU, or may include a function of sequentially transferring all received RLC SDUs to an upper layer if a predetermined timer expires even if there is a missing RLC SDU.

Alternatively, the in-order transfer of the NR RLC device may include a function of sequentially transferring all RLC SDUs received so far to an upper layer if a predetermined timer has expired even if there is a missing RLC SDU. Further, RLC PDUs may be processed in the order they are received (arrival order, regardless of sequence number) and delivered out of order to the PDCP device (out of order delivery), and when the received RLC PDUs are segmented, segments stored in a buffer or to be received may be received, reconstructed into complete RLC PDUs, processed and delivered to the PDCP device. The NR RLC layer may not include a tandem function and the function may be performed in the NR MAC layer or replaced by a multiplexing function of the NR MAC layer.

In the above, the out-of-order transfer of the NR RLC device refers to a function of transferring RLC SDUs received from a lower layer directly to an upper layer without sequence, may include a function of reassembling and transferring when one RLC SDU is initially divided into several RLC SDUs and received, and may include a function of storing RLC SNs or PDCP SNs of received RLC PDUs, ordering them, and recording missing RLC PDUs.

The NR MACs 40 and S55 may be connected to several NR RLC layers configured in one UE, and main functions of the NR MACs may include the following functions:

-mapping between logical channels and transport channels;

-multiplexing/demultiplexing of MAC SDUs;

-scheduling information reporting;

-error correction by HARQ;

-priority handling between logical channels of one UE;

-prioritizing between UEs by dynamic scheduling;

-MBMS service identification;

-transport format selection; and

-a filling function.

The NR PHY layers S45 and S50 may perform channel coding and modulate upper layer data, generate OFDM symbols and transmit the OFDM symbols through a wireless channel, or demodulate OFDM symbols received via a wireless channel and perform channel decoding to transmit the OFDM symbols to an upper layer.

The detailed structure of the radio protocol structure may vary according to the carrier (or cell) operation method. For example, when the base station transmits data to the UE based on a single carrier (or cell), the base station and the UE use a protocol structure having a single structure per layer, e.g., S00. On the other hand, when the base station transmits data to the UE based on Carrier Aggregation (CA) using a plurality of carriers in a single TRP, the base station and the UE have a single structure below RLC as in S10, but use a protocol structure multiplexing PHY layer through MAC layer. For another example, when the base station transmits data to the UE based on DC (dual connectivity) using a plurality of carriers among a plurality of TRPs, the base station and the UE have a single structure of RLC or less as in S20, but use a protocol structure of multiplexing PHY layers through a MAC layer.

Referring to the description above regarding PDCCH and beam configuration, it is difficult to achieve the required reliability in a scenario requiring high reliability, such as URLLC, because Rel-15 and Rel-16 NR currently do not support duplicate PDCCH transmissions. The present disclosure improves PDCCH reception reliability of a UE by providing a PDCCH repetition transmission method through a plurality of transmission/reception points (TRPs). Specific methods are described in detail in the following examples.

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The present disclosure applies to FDD and TDD systems. In the following of the present disclosure, upper layer signaling (or upper layer signaling) is a signaling method from a base station to a UE using a downlink data channel of a physical layer or a signaling method from a UE to a base station using an uplink data channel of a physical layer, and may be referred to as RRC signaling, PDCP signaling, or Medium Access Control (MAC) Control Element (CE).

In the following of the present disclosure, in determining whether to apply cooperative communication, the UE may use various methods, for example, a PDCCH allocating a PDSCH to apply cooperative communication has a specific format, the PDCCH allocating a PDSCH to apply cooperative communication includes a specific indicator indicating whether to apply cooperative communication, the PDCCH allocating a PDSCH to apply cooperative communication is scrambled by a specific RNTI, or it is assumed that cooperative communication is applied to a specific portion indicated by an upper layer. Hereinafter, for convenience of description, a case in which the UE receives the PDSCH based on the similar condition application cooperative communication will be referred to as a non-coherent joint transmission (NC-JT) case.

In the present disclosure, determining the priority between a and B may variously refer to selecting one having a higher priority according to a predetermined priority rule and performing a corresponding operation or omitting or deleting an operation having a lower priority, or the like.

In the following of the present disclosure, the above examples are described by means of several embodiments, but these embodiments are not independent and one or more embodiments may be applied simultaneously or in combination.

[ associated with NC-JT ]

According to one embodiment of the present disclosure, non-coherent joint transmission (NC-JT) may be used for a UE to receive PDSCH from multiple TRPs.

Unlike the existing system, the 5G wireless communication system can support all services requiring a high transmission rate, services having a very short transmission delay, and services requiring a high connection density. In a wireless communication network including a plurality of cells, transmission and Reception Points (TRPs), or beams, coordinated transmission between each cell, TRP, and/or beam may satisfy various service requirements by increasing the signal strength received by a UE or efficiently performing interference control between each cell, TRP, and/or beam.

Joint Transmission (JT) is the above-described representative coordinated transmission technique, and is a technique that increases the signal strength or throughput received by a UE by transmitting signals to one UE through a plurality of different cells, TRPs, or/beams. In this case, characteristics of each cell, TRP, and/or channel between the beam and the UE may be significantly different, and in particular, in case of each cell, TRP, and/or incoherent joint transmission (NC-JT, incoherent joint transmission) supporting non-phase interference coding between beams, a single precoding, MCS, resource allocation, TCI indication, etc. may be required according to channel characteristics of each unit, channel characteristics of TRP, or/and a link between the beam and the UE.

The NC-JT transmission described above may be applied to at least one of a Physical Downlink Shared Channel (PDSCH), a Physical Downlink Control Channel (PDCCH), a Physical Uplink Shared Channel (PUSCH), and a Physical Uplink Control Channel (PUCCH). When transmitting PDSCH, transmission information such as precoding, MCS, resource allocation, TCI, etc. is indicated as DL DCI, and for NC-JT transmission, transmission information per unit, TRP, and/or beam may be indicated independently. Such independent indication becomes a major factor in increasing the payload required for DL DCI transmission, which may adversely affect the reception performance of the PDCCH transmitting the DCI. Therefore, for JTs supported by PDSCH, it is necessary to carefully design a trade-off between DCI information amount and control information reception performance.

Fig. 19 illustrates an example of an antenna port configuration and resource allocation for transmitting PDSCH using cooperative communication in a wireless communication system according to one embodiment of the present disclosure.

Referring to fig. 19, there are illustrated a PDSCH transmission example of each Joint Transmission (JT) technique and an example of allocating radio resources for each TRP.

Referring to fig. 19, an example 1900 of coherent joint transmission (C-JT) supporting phase interference coding between each cell, TRP, and/or beam is illustrated.

In the case of C-JT, TRP a 1905 and TRP B1910 transmit single data (PDSCH) to UE 1915, and joint precoding may be performed among multiple TRPs. This may refer to transmitting DMRS through the same DMRS port so that TRP a 1905 and TRP B1910 transmit the same PDSCH. For example, each of TRP a 1905 and TRP B1910 may transmit DRMS to the UE through DMRS port a and DMRS B. In this case, the UE may have a piece of DCI information on receiving PDSCH demodulated based on DMRS transmitted through DMRS ports a and DMRS B.

Fig. 19 illustrates an example 1920 of non-coherent joint transmission (NC-JT) supporting non-coherent precoding between each cell, TRP, and/or beam for PDSCH transmission.

In the case of NC-JT, PDSCH is transmitted to the UE 1935 for each cell, TRP, and/or beam, and separate precoding may be applied to each PDSCH. Each cell, TRP, and/or beam transmits a different PDSCH or different PDSCH layer to the UE compared to single cell, TRP, and/or beam transmissions to improve throughput. Furthermore, each cell, TRP and/or beam repeatedly transmits the same PDSCH to the UE, and this may potentially improve reliability compared to single cell, TRP and/or beam transmissions. For ease of description, cells, TRPs, and/or beams are hereinafter collectively referred to as TRPs.

In this case, various radio resource allocations, such as a case where all frequency and time resources used by a plurality of TRPs for PDSCH transmission are the same as 1940, a case where the frequency and time resources used by the plurality of TRPs are not overlapped with 1945 at all, and a case where some frequency and time resources used by the plurality of TRPs are overlapped with 1950, may be considered.

To allocate multiple PDSCH to one UE at the same time to obtain NC-JT support, DCI of various types, structures, and relationships may be considered.

Fig. 20 illustrates an example of a Downlink Control Information (DCI) configuration for NC-JT in which each TRP transmits a different PDSCH or different PDSCH layers to UEs in a wireless communication system according to one embodiment of the present disclosure.

Referring to fig. 20, in case of transmitting N-1 different PDSCHs among N-1 additional TRPs (TRP #1 to trp# (N-1)), case #1 2000 is an example in which control information of the PDSCH transmitted in the N-1 additional TRPs is transmitted independently of control information of the PDSCH transmitted in the serving TRP, except for the serving TRP (TRP # 0) for single PDSCH transmission. That is, the UE may acquire control information of PDSCH transmitted in different TRPs (TRP #0 to trp# (N-1)) through independent DCIs (DCI #0 to dci# (N-1)). The formats may be the same or different between the individual DCIs, and the payloads may be the same or different between the DCIs. In the case of #1 described above, each PDSCH control or allocation degree of freedom may be completely ensured, but when each DCI is transmitted in a different TRP, a coverage difference may occur for each DCI and reception performance may be degraded.

In the case of transmitting N-1 different PDSCHs among N-1 additional TRPs (TRP #1 to trp# (N-1)), case #22005 shows control information (DCI) for transmitting a PDSCH among (N-1) additional TRPs, in addition to a service TRP (TRP # 0) for single PDSCH transmission, and each of these DCIs an example of being transmitted depending on the control information of a PDSCH transmitted in the service TRP.

For example, in the case where dci#0 is control information of PDSCH transmitted in service TRP (trp#0), all information elements including DCI format 1_0, DCI format 1_1, and DCI format 1_2, but in the case where shortened DCI (hereinafter abbreviated DCI) (sdi#0 to sdi# (N-2)) is control information of PDSCH transmitted in cooperative TRP (trp#1 to trp# (N-1)), only some information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2 can be included. Therefore, in the case where the sdi transmits control information on the PDSCH transmitted in the cooperative TRP, since the payload is smaller than normal DCI (nri) of PDSCH-related control information transmitted from the serving TRP, a reserved bit may be included as compared to nri.

In case #2 described above, each PDSCH control or allocation degree of freedom may be limited according to the content of the information element included in the sdi, but since the receiving performance of the sdi is better than that of the nci, the probability of coverage difference of each DCI may be reduced.

In the case of transmitting N-1 different PDSCHs among N-1 additional TRPs (TRP #1 to TRP # (N-1)) other than the service TRP (TRP # 0) for a single PDSCH transmission, case #32010 shows one control information (DCI) for transmitting PDSCH of N-1 additional TRPs, and the DCI is an example of transmission depending on control information of PDSCH transmitted in the service TRP.

For example, in the case where dci#0 is control information of PDSCH transmitted in service TRP (trp#0), all information elements including DCI format 1_0, DCI format 1_1, and DCI format 1_2, and in the case of control information of PDSCH transmitted in cooperative TRP (trp#1 to trp# (N-1)), only some information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2 can be collected and transmitted in one "secondary" DCI (sdi). For example, the sdi may include at least one HARQ-related information such as frequency domain resource allocation, time domain resource allocation, and MCS of cooperative TRP. Further, for information not included in the scdci, such as a bandwidth part (BWP) indicator or a carrier indicator, DCI (dci#0, normal DCI, and ncdci) serving TRP may be followed.

In case #32010, each PDSCH control or allocation freedom may be limited according to the content of the information element included in the sdi, but the sdi reception performance may be adjusted and the complexity of DCI blind decoding of the UE may be reduced compared to case #1 2000 or case #2 2005.

In the case where N-1 different PDSCHs are transmitted among N-1 additional TRPs (TRP #1 to TRP # (N-1)) other than the service TRP (TRP # 0) for single PDSCH transmission, case #42015 is to transmit control information on the PDSCH transmitted among the N-1 additional TRPs from the same DCI (long DCI, lci) as control information on the PDSCH transmitted in the service TRP. That is, the UE may acquire control information of PDSCH transmitted in different TRPs (TRP #0 to trp# (N-1)) through a single DCI. In case #42015, the DCI blind code decoding complexity of the UE may not increase, but the PDSCH control (allocation) degree of freedom may be low, for example, the number of cooperative TRPs is limited according to a long DCI payload limitation.

In the following description and embodiments, scdci may refer to various auxiliary DCIs, for example, shortened DCI, secondary DCI, or general DCI (DCI formats 1_0 to 1_1 described above), including PDSCH control information transmitted in cooperative TRP, and if no special limitation is specified, the description is equally applicable to various auxiliary DCIs.

In the following description and embodiments, the case #1 2000, the case #2 2005, and the case #3 2010, which support NC-JT using one or more DCIs (PDCCHs), may be distinguished as a plurality of PDCCH-based NC-JTs, and the case #42015, which supports NC-JTs using a single DCI (PDCCH), may be distinguished as a single PDCCH-based NC-JTs. In PDSCH transmission based on multiple PDCCHs, the CORESET of DCI scheduling a service TRP (trp#0) and the CORESET of DCI scheduling a cooperation TRP (trp#1 to trp# (N-1)) can be distinguished. As a method of distinguishing CORESET, a distinguishing method may be a distinguishing method by an upper layer indicator of each CORESET, a distinguishing method by a beam configuration of each CORESET, or the like. Further, in NC-JT based on a single PDCCH, a single DCI schedules a single PDSCH having a plurality of layers instead of scheduling a plurality of PDSCHs, and the plurality of layers may be transmitted from a plurality of TRPs. In this case, the connection relationship between TRP of a layer and a transmission layer may be indicated by a Transmission Configuration Indicator (TCI) indication of the layer.

In embodiments of the present disclosure, the "cooperative TRP" may be replaced with various terms such as "cooperative panel" or "cooperative beam" when actually applied.

In the embodiments of the present disclosure, "when NC-JT is applied" may be interpreted differently according to circumstances, such as "when one UE receives one or more PDSCH simultaneously in one BWP", "when the UE receives PDSCH indicated based on two or more Transmission Configuration Indicators (TCIs) simultaneously in one BWP", "when PDSCH received by the UE is associated with one or more DMRS port groups", and the like, but for convenience of explanation, one expression is used.

In the present disclosure, the radio protocol structure of NC-JT may be used in various ways according to TRP deployment scenarios. For example, if there is no backhaul delay or backhaul delay is low between cooperative TRPs, a MAC layer multiplexing-based structure (CA-like method) similar to S10 in fig. 18 may be used. On the other hand, when the backhaul delay between cooperative TRPs is too high to be ignored (for example, when the exchange of CSI, scheduling, HARQ-ACK, etc. information between cooperative TRPs requires 2ms or more), a strong anti-delay characteristic can be ensured by using an independent structure for each TRP from the RLC layer, similar to S20 in fig. 18 (DC-like method).

The UE supporting C-JT/NC-JT may receive C-JT/NC-JT related parameters or set values from an upper layer configuration and set RRC parameters of the UE based on the received parameters. To configure the upper layers, the UE may utilize UE capability parameters, such as tci-StatePDSCH. Here, the UE capability parameter, for example TCI-StatePDSCH, may define TCI states for PDSCH transmission purposes, and the number of TCI states may be set to 4, 8, 16, 32, 64, and 128 in FR1, 64 and 128 in FR2, and up to 8 states represented by 3 bits of the TCI field of DCI may be set by a MAC CE message in the set number. The maximum value 128 refers to a value indicated by maxnumberconfirmedtcistetes percc in the tci-StatePDSCH parameter included in the UE capability signaling. In this way, a series of configuration procedures from an upper layer configuration to a MAC CE configuration can be applied to a beamforming indication or a beamforming change command of at least one PDSCH in one TRP.

[ multiple TRPs based on multiple DCIs ]

According to embodiments of the present disclosure, a downlink control channel for NC-JT transmission may be configured based on a plurality of PDCCHs.

In NC-JT based on multiple PDCCHs, when DCI is transmitted for PDSCH scheduling of each TRP, there may be CORESET or search space divided for each TRP therein. The CORESET or search space of each TRP may be configured for at least one of the following.

In one example, the upper layer index configuration of each CORESET: the CORESET configuration information configured by the upper layer may include an index value, and the TRP transmitting the PDCCH in the corresponding CORESET may be distinguished by a set index value of each CORESET. That is, in the CORESET set having the same upper layer index value, the same TRP may be considered to transmit the PDCCH, or the PDSCH scheduling the same TRP may be transmitted. The above index of each CORESET may be named coresetpoil index, and the PDCCH may be considered to be transmitted from the same TRP of CORESET setting the same coresetpoil index value. In the case of CORESET where the coresetpolindex value is not set, the default value of coresetpolindex may be considered to have been set, and may be 0.

In one example, multiple PDCCH-Config configurations: multiple PDCCH-Configs are configured in one BWP, and each PDCCH-Config may include a PDCCH configuration of each TRP. That is, the CORESET list of each TRP and/or the search space list of each TRP may be configured in one PDCCH-Config, and one or more CORESETs and one or more search spaces included in one PDCCH-Config may be regarded as corresponding to a specific TRP.

In one example, CORESET beam/beam group configuration: the TRP corresponding to the corresponding CORESET may be distinguished by the beam or beam group configured for each CORESET. For example, when the same TCI state is configured in a plurality of coreets, the coreets may be considered to be transmitted through the same TRP, or a PDCCH scheduling PDSCH of the same TRP may be considered to be transmitted from the corresponding coreet.

In one example, a search space beam/beam set configuration: one beam or beam group is configured for each search space, and in this way, TRPs of each search space can be distinguished. For example, when the same beam/beam group or TCI state is configured in a plurality of search spaces, the same TRP may be considered to transmit a PDCCH in the corresponding search space or a PDCCH scheduling PDSCH of the same TRP may be transmitted in the corresponding search space.

As described above, PDSCH and HARQ-ACK information about each TRP may be classified by differentiating CORESET or search space of each TRP, and in this way, an independent HARQ-ACK codebook may be generated for each TRP and an independent PUCCH resource may be used.

The setting may be independent for each cell or for each BWP. For example, although two different coresetpoolndex values are set in the PCell, coresetpoolndex values may not be set in a particular Scell. In this case, NC-JT transmission may be considered to be configured in the PCell, while NC-JT transmission is configured in the SCell where the coresetpoolndex value is not set.

[ multiple TRPs based on Single DCI ]

According to another embodiment of the present disclosure, the downlink beam for NC-JT transmission may be configured based on a single PDCCH.

In NC-JT based on a single PDCCH, PDSCH transmitted by multiple TRPs may be scheduled using one DCI. In this case, the number of TCI states may be used as a method of indicating the number of TRPs transmitting the corresponding PDSCH. That is, if the number of TCI states indicated by DCI scheduling PDSCH is 2, it may be regarded as NC-JT transmission based on a single PDCCH, and if the number of TCI states is 1, it may be regarded as single TRP transmission. The DCI-indicated TCI state may correspond to one or both of MAC-CE-activated TCI states. When the TCI state of the DCI corresponds to two TCI states of MAC-CE activation, a correspondence between TCI code bits indicated by the DCI and the TCI states of MAC-CE activation may be established, and the correspondence may be a time when the two TCI states of MAC-CE activation correspond to the TCI code bits.

The above configuration may be independent for each cell or each BWP. For example, one PCell may have at most two activated TCI states corresponding to one TCI code bit, while a particular SCell may have at most one activated TCI state corresponding to one TCI code bit. In this case, NC-JT transmission may be considered to be configured in the PCell, while NC-JT transmission is not configured in the SCell described above.

Description of the embodiments

Referring to the description above regarding the PDCCH transmitting/receiving arrangement and the transmission beam arrangement, in the current Rel-15/16NR, for a plurality of control resource sets that may be configured for a single or a plurality of cells, only other control resource sets having the same QCL-TypeD characteristics as the control resource set determined by the above rule can be received in a specific PDCCH monitoring period. That is, multiple time-overlapping control resource sets can be received within a particular PDCCH monitoring period using only one QCL-TypeD.

Meanwhile, in Rel-17 FeMIMO, a method of improving PDCCH reception reliability by repeating PDCCH transmission is being standardized. As a method of PDCCH retransmission, there may be a method of retransmitting a control resource set connected to each of a plurality of search spaces explicitly connected by upper layer signaling through different TRP separated time or frequency resources, and a method of retransmitting by configuring a plurality of TCI states in one control resource set in the SFN method.

Thus, in case of PDCCH retransmission, since retransmission is performed using a plurality of QCL-type from a plurality of TRPs within a specific time, it is possible to relax the limitation of currently receiving a plurality of control resource sets where only one QCL-type feature overlaps within a specific time in order to achieve reception in this aspect. The present disclosure provides a method for determining a priority of a reception control resource set when performing a repeated PDCCH transmission in consideration of a plurality of TRPs so that a UE can receive the repeated PDCCH transmission. Specific methods will be described in detail in the following examples.

For convenience, in the following description of the present disclosure, upper layer/L1 parameters such as TCI status or spatial relationship information, or cells, transmission points, panels, beams, and/or transmission directions classified by indicators such as cell ID, TRP ID, panel ID, etc., are unified and described as Transmitting Reception Points (TRP). Accordingly, TRP may be replaced with one of the above terms as appropriate when applied in practice.

In the following of the present disclosure, the UE may determine whether to apply cooperative communication using various methods, for example, a PDCCH allocating a PDSCH to apply cooperative communication has a specific format, a PDCCH allocating a PDSCH to apply cooperative communication may include a specific indicator indicating whether to apply cooperative communication, a PDCCH allocating a PDSCH to apply cooperative communication is scrambled to a specific RNTI, or it is assumed that cooperative communication is applied to a specific portion indicated by an upper layer. Hereinafter, for convenience of description, a UE receiving PDSCH based on the above-described similar condition application cooperative communication may be referred to as NC-JT case.

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the following description, a base station is an entity that allocates resources for a terminal, and may be at least one of a eNode B, an eNode B, a node B, a Base Station (BS), a radio access unit, a base station controller, or a node on a network. A terminal may include a User Equipment (UE), a Mobile Station (MS), a cellular phone, a smart phone, a computer, and a multimedia system capable of performing a communication function. In the following description, embodiments of the present disclosure may be described taking a 5G system as an example, but embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. Examples of such communication systems may include LTE or LTE-a mobile communication systems and mobile communication technologies developed in super 5G. Accordingly, based on a determination by those skilled in the art, embodiments of the present disclosure may also be applied to other communication systems with certain modifications without departing significantly from the scope of the present disclosure.

Further, in describing the present disclosure, when it is determined that a detailed description of known functions or configurations incorporated within the present disclosure may unnecessarily obscure the subject matter of the present disclosure, the detailed description will be omitted. The terms to be described below are terms defined in consideration of functions in the present disclosure, and may be different according to users, user intention, or habits. Accordingly, the definition of the terms should be based on the contents of the entire specification.

In describing the disclosure below, upper layer signaling may be a combination corresponding to at least one or more of the following signaling:

MIB (master information block).

SIB (system information block) or SIB X (x=1, 2).

-RRC (radio resource control); and

MAC (medium access control) CE (control element).

Further, the L1 signaling may be at least one or a combination of signaling methods corresponding to using a physical layer channel or the following signaling methods:

PDCCH (physical downlink control channel);

DCI (downlink control information);

-UE specific DCI;

-a set of common DCI;

-common DCI;

scheduling DCI (e.g., DCI for scheduling downlink or uplink data);

non-scheduling DCI (e.g., DCI not used to schedule downlink or uplink data).

PUCCH (physical uplink control channel); and

UCI (uplink control information).

Further, in the present disclosure, determining the priority between a and B may be mentioned in different manners, for example, selecting one having a higher priority according to a predetermined priority rule and performing a corresponding operation or omitting or deleting an operation having a lower priority, or the like.

< first embodiment: PDCCH repeated transmission method based on multiple TRPs

As an embodiment of the present disclosure, a PDCCH repetition transmission method considering a plurality of TRPs will be described. PDCCH retransmission considering multiple TRPs may have various methods depending on how each TCI state to be applied when transmitting a PDCCH in each TRP is applied to the above various parameters for PDCCH transmission. For example, various parameters for PDCCH transmission applying different TCI states may include CCEs, PDCCH candidate sets, control resource sets, search spaces, and the like. In case of considering repeated PDCCH transmission of a plurality of TRPs, a soft combining scheme, a selection scheme, and the like may be regarded as a reception method of the UE.

The method of implementing PDCCH retransmission through a plurality of TRPs may be the following five methods, and for at least one of the five methods, the base station may configure the UE through upper layer signaling, or instruct the UE through L1 signaling, or configure and instruct the UE through a combination of upper layer signaling and L1 signaling.

Method 1-1 repeated transmission method of multiple PDCCHs having the same payload

Method 1-1 is a method of repeatedly transmitting a plurality of pieces of control information having the same DCI format and payload. Each of the above-described control information may indicate information on PDSCH scheduled to be repeatedly transmitted, for example, { pdsch#1, pdsch#2, & gt, pdsch#y }, which is repeatedly transmitted over a plurality of slots. The payload of each repeatedly transmitted control information may also be expressed as PDSCH scheduling information of each control information, for example, the number of PDSCH repeated transmissions, the time axis of PDSCH resource allocation information, that is, the slot offset k_0 between the control information and pdsch#1, the number of PDSCH symbols, etc., and the frequency axis PDSCH resource allocation information, DMRS port allocation information, PDSCH to HARQ-ACK timing, PUCCH resource indicator, etc., are the same. The UE may improve the reception reliability of the control information by soft combining the repeated transmission control information having the same payload.

For soft combining, the UE needs to know the resource location and the number of repeated transmissions of control information to be repeatedly transmitted in advance. For this, the base station may instruct in advance the configuration of the time domain, frequency domain, and spatial domain resources of the above-described repeated transmission control information. When the control information is repeatedly transmitted on the time axis, the control information may be repeatedly transmitted through different CORESETs, repeatedly transmitted on different search space sets within one CORESET, or may be repeatedly transmitted through different PDCCH monitoring occasions in one CORESET and one search space set. The unit of repeated transmission resources (CORESET unit, search space set unit, and PDCCH monitoring occasion unit) and the location of repeated transmission resources on the time axis (PDCCH candidate index, etc.) may be indicated by an upper layer configuration of the base station, etc. In this case, the number of times of PDCCH retransmission and/or a list of TRPs participating in retransmission and a transmission mode may be explicitly indicated, and upper layer indication or MAC-CE/L1 signaling may be used as an explicit indication method. In this case, the TRP list may be expressed in the form of TCI status or QCL acceptance as described above.

When the control information is repeatedly transmitted on the frequency axis, the control information may be repeatedly transmitted through different CORESETs, through different PDCCH candidates within one CORESET, or for each CCE. The unit of the repeated transmission resource and the position of the repeated transmission resource on the frequency axis may be indicated by an upper layer configuration of the base station or the like. Further, the number of repeated transmissions and/or the list of TRPs participating in the repeated transmissions and the transmission mode may be explicitly indicated, and upper layer indication or MAC-CE/L1 signaling may be used as an explicit indication method. In this case, the TRP list may be expressed in the form of TCI status or QCL acceptance as described above.

When the control information is repeatedly transmitted on the spatial axis, the control information may be repeatedly transmitted through different CORESETs, or two or more TCI states may be configured in one CORESET of the repeated transmission.

Method 1-2 a method of repeatedly transmitting a plurality of pieces of control information having different DCI formats and/or payloads.

Method 1-2 is a method of repeatedly transmitting a plurality of pieces of control information having different DCI formats and/or payloads. The control information schedules PDSCH repeatedly transmitted, and the number of PDSCH repeated transmissions indicated by each control information may be different from each other. For example, pdcch#1 may indicate information about scheduling { pdsch#1, pdsch#2,..the pdsch#y }, while pdcch#2 may indicate information about scheduling { pdsch#2,..the pdsch#y }, and pdcch#x may indicate information about scheduling { pdsch#y }. An advantage of this method of repeatedly transmitting control information is that the total delay time required for repeated transmission of control information and PDSCH can be reduced as compared to method 1-1. On the other hand, in this method, since payloads of each of the repeatedly transmitted control information may be different from each other, soft combining of the repeatedly transmitted control information is impossible, and thus reliability may be lower than that of the method 1-1.

In the method 1-2, the UE does not need to know the resource location of the control information to be repeatedly transmitted and the number of repeated transmissions in advance, and the UE can independently decode and process each repeated transmitted control information. If the UE decodes a plurality of retransmission control information for the same PDSCH, only the first retransmission control information can be processed and the second and subsequent retransmission control information can be ignored. Alternatively, the resource position of the control information to be repeatedly transmitted and the number of repeated transmissions may be indicated in advance, and the indication method may be the same as the method described in the above method 1.

Methods 1-3 a method of repeatedly transmitting each of a plurality of pieces of control information having different DCI formats and/or payloads.

Methods 1-3 are methods of repeatedly transmitting each of a plurality of pieces of control information having different DCI formats and/or payloads. In this case, each control information repeatedly transmitted has the same DCI format and payload. Since soft combining of a plurality of control information pieces is impossible in the method 1-2, reliability may be lower than that of the method 1-1, and in the method 1-1, the total delay time required for repeatedly transmitting the control information and PDSCH may be increased. Method 1-3 is a method that takes advantage of the advantages of methods 1-1 and 1-2, and control information can be transmitted with higher reliability than method 1-2 while reducing the total delay time required for repeated transmission of control information and PDSCH compared to method 1-1.

In method 1-3, the control information repeatedly transmitted may be decoded and soft-combined using soft-combining in method 1-1 and separate decoding in method 1-2. For example, first transmission control information repeatedly transmitted among a plurality of control information pieces that may have different DCI formats and/or payloads may be decoded as shown in method 1-2, and repeated transmission of the decoded control information may be soft-combined as shown in method 1-1.

Meanwhile, the base station may select and configure one of the above methods 1-1, 1-2 or 1-3 to perform repeated control information transmission. The control information retransmission method can be explicitly indicated to the UE by the base station through an upper layer signaling. Alternatively, the control information retransmission method may be indicated in combination with other configuration information. For example, an upper layer configuration indicating a PDSCH repeated transmission method may be combined with a repeated control information transmission indication. When PDSCH is indicated to be repeatedly transmitted by the FDM method, it may be interpreted that control information is repeatedly transmitted only by the method 1-1 because PDSCH repeated transmission of the FDM method has no effect of reducing delay time by the method 1-2. For similar reasons, when PDSCH is indicated to be repeatedly transmitted in the intra-slot TDM method, it may be interpreted that control information is repeatedly transmitted through method 1-1. On the other hand, when the PDSCH is indicated to be repeatedly transmitted in the inter-slot TDM method, the above-described method 1-1, 1-2, or 1-3 for control information repetition transmission may be selected by upper layer signaling or L1 signaling.

On the other hand, the base station may explicitly indicate the control information repeated transmission unit to the UE through configuration of an upper layer or the like. Alternatively, the control information repeated transmission unit may be indicated in combination with other configuration information. For example, a superstructure indicating a PDSCH retransmission method may be combined with the control information retransmission unit. When PDSCH is indicated as being repeatedly transmitted through the FDM method, it may be interpreted that control information is repeatedly transmitted to FDM or SDM because there is no effect of reducing delay time due to repeated transmission of PDSCH in the FDM method if control information is repeatedly transmitted, for example, in the inter-slot TDM method. For similar reasons, when PDSCH is indicated as being repeatedly transmitted in an intra-slot TDM approach, it may be interpreted that control information is repeatedly transmitted by TDM, FDM, or SDM in the slot. On the other hand, when PDSCH is indicated to be repeatedly transmitted in the inter-slot TDM method, it may be selected by means of upper layer signaling or the like so that control information may be repeatedly transmitted through a plurality of inter-slot TDM, intra-slot TDM, FDM, or SDM.

Methods 1-4 a PDCCH transmission method in which a TCI state is applied to different CCEs in the same PDCCH candidate set.

Methods 1-4 may apply different TCI states, i.e., from multiple TRPs to different CCEs in the PDCCH candidate set, to improve PDCCH reception performance without PDCCH retransmission. Although this method is not a retransmission of the PDCCH, it may be a method of obtaining spatial diversity in the PDCCH candidate set because different CCEs in the PDCCH candidate set are transmitted by applying different TCI states to each TRP. Different CCEs applying different TCI states may be divided into a time dimension or a frequency dimension, and the UE needs to know in advance the location of resources applying different TCI states. The UE may receive different CCEs in the same PDCCH candidate set, applying different TCI states, and decode them independently or once.

Methods 1-5 a PDCCH transmission method (SFN method) in which a plurality of TCI states are applied to all CCEs in the same PDCCH candidate set.

Methods 1-5 may apply a plurality of TCI states to all CCEs in a PDCCH candidate set to improve PDCCH reception performance without PDCCH repetition transmission, and transmit all CCEs through an SFN method. The corresponding method is not PDCCH repetition transmission, but a method that can obtain spatial diversity through SFN transmission at the same CCE location in the PDCCH candidate set. The UE may receive CCEs of the same location where different TCI states are applied in the same PDCCH candidate set and independently decode or decode once using some or all of the multiple TCI states.

< example 2: reporting UE capability related to Soft combining at PDCCH retransmission >

The UE may report UE capabilities related to soft combining when the PDCCH is repeatedly transmitted to the base station, and various methods may be performed for this. The specific method is as follows.

UE capability reporting method 1 the UE can report in possible or impossible form only whether soft combining is possible during repeated PDCCH transmission to the base station.

For example, if the UE reports information that soft combining is possible during repeated PDCCH transmission to the base station as UE capability, the base station may determine (e.g., the UE determines that soft combining may be performed at the LLR level) whether soft combining of the UE may be performed to the most flexible extent, and may notify the UE of the PDCCH repetition transmission related configuration as flexibly as possible when configuring the PDCCH transmission related configuration. In this case, as an example related to repeating PDCCH configuration, the base station may inform the UE of the corresponding configuration, assuming that the UE may perform soft combining between control resource sets or search spaces having different configurations, soft combining between PDCCH candidates within the same aggregation level, or soft combining between PDCCH candidates between different aggregation levels.

As another example, if the UE reports soft combining during performance of repeated PDCCH transmissions to the base station as UE capability, the base station may most conservatively determine (e.g., the UE determines that soft combining may be performed at the OFDM symbol level) the soft combining level available to the UE and most strictly inform the UE of the UE PDCCH repetition transmission related configuration when configuring the PDCCH transmission related. In this case, as an example related to repeating PDCCH configuration, the base station may inform the UE of the corresponding configuration, assuming that the UE may perform soft combining between a plurality of control resource sets having the same configuration or soft combining between PDCCH candidates.

The UE capability reporting method 2 is a soft combining operation available in the UE that expresses the UE capability in more detail than the above-described UE capability reporting method 1, and the UE may divide the soft combining availability level when performing PDCCH repetition transmission and report the soft combining availability level as the UE capability to the base station. That is, in each signal level generated during the reception operation of the UE, the UE may identify a signal level that may be applied to soft combining of repeated PDCCH transmissions and may report the information as UE capabilities to the base station. For example, the UE may advertise that soft combining is available at the OFDM symbol level, that soft combining is available at the modulation symbol level, and that soft combining is available at the LLR level in the form of a signal level at which soft combining may be applied. Based on each signal level reported by the UE, the base station may inform the appropriate configuration so that the UE may perform soft combining based on the reported UE capabilities.

[ UE capability reporting method 3] when PDCCH is repeatedly transmitted, the UE can transmit to the base station a restriction required for soft combining on the UE side as UE capability. For example, the UE may report to the base station that the configuration of each control resource set including two duplicate PDCCHs may be the same. As another example, the UE may report to the base station that two duplicate PDCCH candidates may have at least the same aggregation level.

[ UE capability report method 4] when receiving PDCCH retransmission from a base station, a UE can report supported PDCCH retransmission methods through UE capability. For example, the UE may report support methods 1-5 (SFN transmission methods) to the base station. For another example, the UE may report to the base station that the intra-slot TDM, inter-slot TDM, or FDM scheme is supported in method 1-1 (multiple PDCCH repetition transmission method with the same payload). Specifically, in case of TDM, the UE may report the maximum value of the time interval between two duplicate PDCCHs to the base station. For example, if the UE reports that the PDCCH is repeated twice with a maximum of 4 OFDM symbols, when the base station performs the repetition TDM-based PDCCH transmission for the UE based on the corresponding information, the time interval between the two repetition PDCCHs may need to be adjusted to 4 OFDM symbols or less.

The UE capability reporting method described above may be configured as a combination of two or more in practical applications. For example, UE reporting is available at the LLR level by [ UE capability reporting method 2] reporting soft combining, while reporting two duplicate PDCCH candidates by [ UE capability reporting method 3] may have the same aggregation level, and reporting UE supporting TDM PDCCH retransmission by [ UE capability reporting method 4], but may report a maximum of 4 OFDM symbols in the time interval between the two duplicate PDCCHs. Further, the UE may report each UE capability report according to the type of search space or DCI format, or may include information of each search space in each UE capability.

For example, the UE may report UE capabilities of each common search space and UE-specific search spaces, respectively, and may report that duplicate PDCCH transmissions are not supported in the common search spaces, and may perform soft combining while supporting performing duplicate PDCCH transmissions in the UE-specific search spaces. As another example, PDCCH transmission that may support repetition may be reported, and soft combining may be performed for a UE-specific DCI format, while PDCCH repetition transmission may not be supported for a generic DCI format. Further, applications based on various combinations of UE capability reporting methods are possible, but detailed descriptions thereof will be omitted.

< third embodiment: PDCCH repeated transmission and clear connection related configuration method

As an embodiment of the present disclosure, a PDCCH repetition transmission configuration method for enabling soft combining during PDCCH repetition transmission will be described. When the base station performs repeated PDCCH transmission on the UE according to the above-described method 1-1 (multiple PDCCH repeated transmission methods of the same payload) among various PDCCH repeated transmission methods, in order to reduce the number of blind codes, the base station may configure explicit linking or interrelating information of repeated PDCCH candidates through upper layer signaling indicated by L1 signaling, or configure and indicate through a combination of upper layer signaling or L1 signaling, considering whether the UE can perform soft combining. In more detail, there may be various connection methods as follows.

There are various methods for configuring PDCCH retransmission related to upper layer signaling with explicit connection, as follows.

[ PDCCH repetition configuration method 1] when configuration information exists in an upper layer signaling PDCCH-config

The base station may configure PDCCH-repeat-config to the UE for repeated PDCCH transmission and explicit connection related configuration in the upper layer signaling PDCCH-config, and the PDCCH-repeat-config may include the following information:

-PDCCH repetition transmission method-one of TDM, FDM and SFN;

-repeating control resource set-search space combinations used during PDCCH transmission;

-control resource set index-optional;

-search space index-optional;

-aggregation level of explicit connections-optional;

-PDCCH candidate index for explicit connection-optional; and

-frequency resources for explicit connection-optional.

Based on the above information, the base station may configure PDCCH retransmission to the UE through upper layer signaling. For example, if the PDCCH repetition transmission scheme is set to SFN, the control resource set index is set to 1, as a control resource set-search space combination used during the repetition PDCCH transmission, and the search space index is not set, the UE may expect to repeatedly transmit the PDCCH through methods 1-5 (SFN transmission methods) of the control resource set of index 1. In this case, the configured control resource set may receive one or more different TCI states configured by upper layer signaling, may be indicated by L1 signaling or MAC-CE signaling, or may be configured and indicated by a combination of upper layer signaling and L1 signaling or MAC-CE signaling. Further, if the PDCCH repetition transmission method is configured as an SFN, the U may not expect to set a search space index in the control resource set-search space combination for repetition PDCCH transmission.

For another example, if the PDCCH repetition transmission method is set to TDM or FDM, two control resource set-search space combinations for repeated PDCCH transmission are configured, control resource set index 1 and search space index 1 are set for the first combination, control resource set index 2 and search space index 2 are set for the second combination, and the UE may expect to repeatedly transmit the PDCCH using the two control resource set-search space combinations through method 1-1 using the TDM or FDM method. In this case, the configured control resource set may receive a plurality of identical or different TCI states configured by upper layer signaling, may be indicated by L1 signaling or MAC-CE signaling, or may be configured and indicated by a combination of upper layer signaling and L1 signaling or MAC-CE signaling. Further, if the PDCCH repetition transmission method is configured as TDM or FDM, the UE may be expected to be configured with at most two control resource set-search space combinations used during the repetition PDCCH transmission, and the control resource set and the search space index may be simultaneously configured in each combination.

Furthermore, the values of these five pieces of information can be updated without reconfiguring RRC based on MAC-CE. If the base station does not configure the PDCCH-repetition-configuration to the UE, the UE may not expect to repeat the PDCCH, but may expect to perform PDCCH transmission only once. All of the aggregation levels, PDCCH candidate indexes, and frequency resources for explicit connection described above may not be configured, or at least one of them may be configured according to an explicit connection method described below.

PDCCH repetition configuration method 2 when configuration information exists in upper layer signaling of a search space

The base station may inform the UE by adding upper layer signaling for repeated PDCCH transmissions in the upper layer signaling searchSpace of the search space. For example, another upper layer signaling in the searchSpace, referred to as a repetition parameter, is set to "on" (on) or "off" (off) so that the base station can configure a corresponding search space for repeated transmission. The search space to be repeatedly set to "on" (on) may be one or two per bandwidth portion. For example, if earchSpaceId is set to 1, controlresourcestid is set to 1, and repetition is set to on in upper signaling searchSpace of search space index 1, the UE may expect to perform repetition PDCCH transmission according to methods 1-5 (SFN transmission method) in control resource set 1 connected to search space 1.

As another example, if searchSpace is set to 1, control resource set id is set to 1, and repetition is set to on in the upper layer signaling searchSpace of search space index 1, and searchSpace is set to 2, control resource set id is set to 2, and repetition is set to on in the upper layer signaling searchSpace of search space index 2, the UE may know that repeated PDCCH transmission is performed by TDM or FDM according to method 1-1 between control resource set 1+search space 1 and control resource set 2+search space 2 combination. TDM and FDM may be divided by upper layer signaling according to the time and frequency configurations of control resource sets 1 and 2 and search spaces 1 and 2, respectively. Further, in the upper layer signaling in which the search space set to on is repeated, the aggregation level or PDCCH candidate index for explicit connection specified in [ PDCCH repetition configuration method 1] may be configured, and either one of them may not be configured, or either one of them may be configured, or both of them may be configured according to the explicit connection method described below.

< example 4: method for determining priority after PDCCH repeated transmission and reception

As an embodiment of the present disclosure, a method of determining priority when receiving a duplicate PDCCH transmission will be described. The UE may report at least one UE capability listed below to the base station as a UE capability with a method of determining priority after receiving the repeated PDCCH transmission.

In one example, whether or not to include a control resource set provided with a plurality of TCI states among a plurality of control resource sets of a plurality of cells overlapping in time in a specific PDCCH monitoring period.

In an example, whether or not a plurality of control resource sets of a plurality of cells overlapping in time in a particular PDCCH monitoring period may be included are respectively connected to a plurality of explicitly connected search spaces.

In one example, the number of receivable maximum received beams or the number of different TCI states or QCL-type characteristics in multiple control resource sets of multiple cells overlapping in time within a particular PDCCH monitoring period.

In one example, the maximum number of receivable different control resource sets of 3) above is considered for all control resource sets connected to a common search space or UE-specific search space among a plurality of control resource sets of a plurality of cells overlapping in time within a specific PDCCH monitoring period.

In one example, the maximum number of receivable different control resource sets of 3) above is considered for all control resource sets connected to the common search space among a plurality of control resource sets of a plurality of cells overlapping in time within a specific PDCCH monitoring period.

In one example, the maximum number of receivable different control resource sets of 3) above is considered for all control resource sets connected to a UE-specific search space among a plurality of control resource sets of a plurality of cells overlapping in time within a specific PDCCH monitoring period.

In one example, a maximum number of control resource sets of multiple TCI states are configured among multiple control resource sets of multiple cells overlapping in time within a particular PDCCH monitoring period.

In an example, a maximum number of paired control resource sets, each connected to a plurality of explicitly connected search spaces, of a plurality of control resource sets of a plurality of cells overlapping in time within a particular PDCCH monitoring period.

If the UE does not report 1) above or reporting is impossible, the UE may not expect a single control resource set configured with a plurality of TCI states among a plurality of control resource sets including a plurality of cells overlapping in time within a specific PDCCH monitoring period, and may expect that a control resource set configured with a plurality of TCI states does not have another control resource set overlapping in time among a plurality of cells during a PDCCH monitoring period corresponding to the control resource set. Similarly, if the UE does not report 2) above or reporting is impossible, the UE may not expect control resource sets respectively connected to the plurality of explicitly connected search spaces among the plurality of control resource sets overlapping in time including the plurality of cells within a specific PDCCH monitoring period, and if each control resource set connected to the plurality of explicitly connected search spaces is repeatedly transmitted through FDM, there is no other control resource set overlapping in time across the plurality of cells during PDCCH monitoring of the corresponding control resource set.

If the UE reports 7) as 2, the UE may expect control resource sets overlapping in time in the cells, and there may be at most two control resource sets configured with TCI states across cells corresponding to the PDCCH monitoring period in a specific PDCCH monitoring period. That is, at most two control resource sets may be connected to multiple TCI states within a corresponding PDCCH monitoring period.

If the UE reports 8) above as 3, the UE may expect that there are at most three control resource set pairs connected to a plurality of explicitly connected search spaces, respectively, across the plurality of cells in the corresponding PDCCH monitoring period in a plurality of control resource sets of the plurality of cells overlapping in time in the specific PDCCH monitoring period. That is, up to three pairs of control resource sets may be connected to three pairs of explicitly connected search spaces, respectively, within a corresponding PDCCH monitoring period.

Further, information that the UE intends to report to the base station through eight UE capabilities may be simultaneously received from a plurality of control resource sets overlapping in time by using a plurality of different QCL-type characteristics. Thus, since eight UE capabilities are information focused on whether multiple PDCCHs can be received, there may be a reporting method for implementing simultaneous reception using multiple QCL-type features at any point in time.

As a method of reporting more general UE capabilities to the base station, UE capabilities received simultaneously based on multiple QCL-type characteristics of the control resource set may be replaced. In this case, the UE reporting the corresponding UE capability may advertise the base station, and at any point in time, all downlink signals (e.g., SSB, CSI-RS, CSI-IM, PRS, DMRS, PTRS, PDSCH, PDCCH, etc.) may be received simultaneously using multiple QCL-type characteristics that overlap in time. Further, the UE may announce to the base station when reporting the corresponding function that simultaneous reception may be achieved using multiple QCL-TypeD characteristics overlapping in time at any point in time for some combinations of the downlink signal examples listed above.

Specific embodiments in consideration of repeated PDCCH transmission and a method of determining priority in consideration of repeated PDCCH transmission using a single control resource set in which a plurality of TCI states are configured or using control resource sets respectively connected to a plurality of explicitly connected search spaces when receiving a PDCCH will be described in detail.

< example 4-1: priority determination method when receiving duplicate PDCCH transmissions using a single set of control resources configured with multiple TCI states >

As an embodiment of the present disclosure, a method of determining PDCCH reception priority in a UE when receiving duplicate PDCCH transmissions using a single control resource set configured with multiple TCI states will be described. If a plurality of control resource sets existing within the active bandwidth overlap in time on a single or a plurality of subcarriers while having the same or different QCL-type characteristics within a specific PDCCH monitoring period, and in particular, if at least one control resource set has a plurality of TCI states within a corresponding PDCCH monitoring period, the UE may perform the QCL priority determination operation considering the following three references.

In one example of reference 1, a method for selecting a reference control resource set to determine whether each control resource set that overlaps in time within a particular PDCCH monitoring period can be received.

In one example of reference 2, a set of control resources simultaneously received within a particular PDCCH monitoring period is selected based on one or more QCL-type characteristics included in the set of control resources selected in reference 1).

In one example of reference 3, when the maximum number of control resource sets that can be monitored in reference 2) is limited, the priority between the control resource sets.

For the method of determining references 1 to 3, the UE may assume that a control resource set connected to a common search space or a UE-specific search space has one or more QCL-type features overlapping in time within a PDCCH monitoring period in consideration of a plurality of subcarriers. For example, if a first control resource set (C1) connected to a first common search space (css#1) in a first subcarrier (cc#1) has N QCL-type features (wns), this control resource set, which will be described below, may be named "cc#1-css#1-C1 wns". For another example, if the third control resource set (C3) connected to the second UE-specific search space (USS#2) in the nth subcarrier (CC#n) has N-1 QCL-TypeD characteristics (w (N-1)), the control resource set may be defined as "CC#n-USS#2-C#3w (N-1)". The corresponding naming scheme may be employed in example 4-1. Based on this, reference 1 can be determined in consideration of the following method.

[ method 1 for determining reference 1]

If the maximum number of the plurality of TCI states that any control resource set can have is N and each common search space and UE-specific search space have the same N value within the active bandwidth portions of all subcarriers, the UE can select a control resource set satisfying reference 1 according to the order of table 51 below. The subcarrier index, the index of the common search space and the UE-specific search space, and the control resource set index are excluded from the naming scheme in the following order.

TABLE 51

As described above, when the subcarrier index, the indexes of the common search space and the UE-specific search space, and the control resource set index are excluded, the corresponding control resource set may be understood as a control resource set having a specific number of QCL-type features connected to the common search space or the UE-specific search space. For example, CSS-CwN may be defined as a control resource set having N QCL-TypeD features connected to a common search space, and USS-Cw (N-2) may be defined as a control resource set having N-2 QCL-TypeD features connected to a UE-specific search space. According to [ table 51], the UE may preferentially select a control resource set having a plurality of QCL-type features among control resource sets connected to the common search space instead of a control resource set having a single QCL-type feature, and may preferentially select a control resource set having a single QCL-type feature among control resource sets connected to the common search space instead of a control resource set having a plurality of QCL-type features among control resource sets connected to the UE-specific search space.

When at least one control resource set corresponding to the priority of any value shown in table 51 exists in the corresponding PDCCH monitoring period, a control resource set connected to a search space having the lowest subcarrier index and the lowest common and UE-specific search space index among the corresponding control resource sets may be determined as a reference control resource set. Further, if there is no control resource set corresponding to the 1 st to nth priorities in the active bandwidth portion of all subcarriers in the corresponding PDCCH monitoring period, it is determined whether there is a PDCCH monitoring period in the control resource set corresponding to the (n+1) th priority, and if there is at least one control resource set, the lowest subcarrier index, the lowest common search space, and the UE-specific search space index in the corresponding control resource set may be determined as the control resource set connected to the search space as the reference control resource set.

For example, if the control resource set CSS-CwN corresponding to the first priority does not exist within the corresponding PDCCH monitoring period, and the control resource set CSS-Cw (N-1) corresponding to the second priority corresponds to the corresponding PDCCH monitoring period, and one CSS-Cw (N-1) of the control resource set corresponding to the second priority is present within each of subcarriers 1 and 2 within the corresponding PDCCH monitoring period, the UE may select the control resource set present in subcarrier 1 as the control resource set conforming to reference 1.

[ method 2 for determining reference 1]

As another approach, the UE may follow the order of table 52 below to determine the set of control resources that meets reference 1. Similar to the above [ method 1 of determining reference 1], the subcarrier index, the index of the common search space and the UE-specific search space, and the control resource set index are excluded from the naming scheme in the following order.

TABLE 52

According to table 52, the UE may preferentially select a control resource set having a plurality of QCL-type features among control resources connected to the common search space instead of a control resource set having a plurality of QCL-type features among control resources connected to the UE-specific search space, may preferentially select a control resource set having a plurality of QCL-type features among control resources connected to the UE-specific search space instead of a control resource set having a single QCL-type feature among control resources connected to the common search space, and in case the control resource set has a single QCL-type, the control resource set connected to the common search space may have a higher priority than the control resource set connected to the UE-specific search space. Similar to [ method 1 of determining reference 1], if there is at least one control resource set corresponding to the priority of any value shown in table 52 in the corresponding PDCCH monitoring period, a control resource set connected to a search space having the lowest subcarrier index and the lowest common and UE-specific search space index among the corresponding control resource sets may be determined as the reference control resource set.

Further, if there is no control resource set corresponding to the 1 st to nth priorities in the active bandwidth portion of all subcarriers in the corresponding PDCCH monitoring period, it is determined whether a PDCCH monitoring period exists for the control resource set corresponding to the (n+1) th priority, and if there is at least one control resource set, a control resource set connected to a search space having the lowest subcarrier index and the lowest common and UE-specific search space index among the corresponding control resource sets is determined as a reference control resource set. For example, for table 52, if the control resource set CSS-CwN corresponding to the first priority is not present in the corresponding PDCCH monitoring period and one CSS-Cw (N-1) is present in either of subcarriers 1 and 2 corresponding to the PDCCH monitoring period as the control resource set corresponding to the second priority, the UE may select the control resource set present in subcarrier 1 as the control resource set conforming to reference 1.

As another example, for [ table 52], if there are no control resource sets from the 1 st priority to the (2N-2) priority within the corresponding PDCCH monitoring period, and there are two CSSs-Cw 1 on subcarrier 1 within the corresponding PDCCH monitoring period, i.e., a control resource set corresponding to the (2N-1) th priority (e.g., there are two CSSs, and each of indexes 1 and 2), the UE may select a control resource set connected to CSS #1 existing in subcarrier 1 as a control resource set conforming to reference 1.

[ method 3 for determining reference 1]

As another approach, the UE may follow the order of table 53 below to determine the set of control resources that meets reference 1. Similar to the above [ method 1 of determining reference 1] and [ method 2 of determining reference 1], the subcarrier index, the index of the common search space and the UE-specific search space, and the control resource set index are excluded from the naming scheme in the following order.

TABLE 53

According to table 53, if the number of QCL-type features of the control resource set connected to the common search space and the control resource set connected to the UE-specific search space is the same, the UE may preferentially select the control resource set connected to the common search space and if the number of QCL-type features is different, the UE may preferentially select the control resource set connected to the common search space having a large number of QCL-type features or the UE-specific search space. Similar to [ method 1 of determining reference 1] and [ method 2 of determining reference 1], if there is at least one control resource set corresponding to the priority of any value shown in table 53 in the corresponding PDCCH monitoring period, a control resource set connected to a search space having the lowest subcarrier index and the lowest common and UE-specific search space index among the corresponding control resource sets may be determined as the reference control resource set.

Further, if there is no control resource set corresponding to the 1 st to nth priorities in the active bandwidth portion of all subcarriers in the corresponding PDCCH monitoring period, it is determined whether the control resource set corresponding to the (n+1) th priority exists or not, and if there is at least one control resource set, a control resource set connected to a search space having the lowest subcarrier index and the lowest common and UE-specific search space index among the corresponding control resource sets may be determined as a reference control resource set. For example, for table 53, if the control resource set CSS-CwN corresponding to the first priority is not present during the corresponding PDCCH monitoring period and one USS-CwN is present in either of subcarriers 1 and 2 corresponding to the PDCCH monitoring period as the control resource set corresponding to the second priority, the UE may select the control resource set present in subcarrier 1 as the control resource set conforming to reference 1.

As another example, for table 53, if there are no control resource sets from the 1 st priority to the (2N-1) priority within the corresponding PDCCH monitoring period, and there are two USS-Cw1 on subcarrier 1 (e.g., USS #1 and USS #2 when there are two UE-specific search spaces) within the corresponding PDCCH monitoring period, i.e., the control resource set corresponding to the second priority, the UE may select the control resource set connected to USS #1 present in subcarrier 1 as the control resource set conforming to reference 1.

The [ method 1 of determining reference 1] to [ method 3 of determining reference 1] are some examples, and another determination method not limited thereto may be used for reference 1. Further, referring to the UE capability of supporting the repeated PDCCH transmission for the above-described common search space in the above-described second embodiment, the UE and the base station may not support the repeated PDCCH transmission for the CSS. In this case, when considering the priority, the priority of the CSS repeated transmission in the consideration tables 51 to 53 may be ignored. More specifically, priorities 1 through N-1 in tables 51 and 52 may be omitted, with the exception of the (2N-1) th priority, odd-numbered priorities (e.g., 1, 3, 5, 2N-3) in table 53.

From [ method 1 of determining reference 1] to [ method 3 of determining reference 1], the following method can be considered for the method of determining reference 2. The precondition for each of the methods described below is that the reference control resource set determined by [ method 1 for determining reference 1] to [ method 3 for determining reference 1] has M (1.ltoreq.M.ltoreq.N) QCL-TypeD characteristics.

[ method 1-1 for determining reference 2 ]

The UE may receive a control resource set connected to the common search space and the UE-specific search space using corresponding QCL-type features, the number and types of which are the same as the specific control resource set determined by reference 1.

[ methods 1-2 for determining reference 2]

The UE may receive a control resource set connected to the common search space using the corresponding QCL-type features, the number and types of which are the same as the specific control resource set determined with reference to 1.

[ methods 1-3 for determining reference 2]

The UE may receive a control resource set connected to the UE-specific search space using the corresponding QCL-type features, the number and type of which are the same as the specific control resource set determined with reference to 1.

[ methods 1-4 for determining reference 2]

The UE may receive the same number and type of QCL-type features as the specific control resource set determined by reference 1 and a control resource set connected to the same type of search space within the corresponding PDCCH monitoring period using the corresponding QCL-type features.

[ method 2-1 for determining reference 2]

The UE may receive a control resource set connected to the common search space and the UE-specific search space while having the same type of QCL-type feature as the specific control resource set determined by reference 1, using the corresponding QCL-type feature within the corresponding PDCCH monitoring period.

[ method 2-2 for determining reference 2]

The UE may receive a control resource set connected to the common search space within a corresponding PDCCH monitoring period using a corresponding QCL-type feature while having the same type of QCL-type feature as the specific control resource set determined by reference 1.

[ methods 2-3 for determining reference 2]

The UE may receive a control resource set connected to the UE-specific search space within a corresponding PDCCH monitoring period using a corresponding QCL-type feature while having at least one QCL-type feature of the same type as the specific control resource set determined by reference 1.

[ method 2-4 for determining reference 2]

The UE may receive a control resource set connected to the same type of search space as the search space connected to the specific control resource set while having the same type of QCL-type feature as the specific control resource set determined by reference 1, using the corresponding QCL-type feature within the corresponding PDCCH monitoring period.

[ method 3-1 for determining reference 2]

The UE may receive a set of control resources corresponding to: all QCL-type features of each control resource set are a subset of all QCL-type features of the specific control resource set determined by reference 1, connected to the control resource sets that exist in the common search space and the UE-specific search space within the corresponding PDCCH monitoring period.

[ method 3-2 for determining reference 2]

The UE may receive a set of control resources corresponding to: all QCL-type features of each control resource set are a subset of all QCL-type features of the particular control resource set determined by reference 1, connected to a common search space that exists within the corresponding PDCCH monitoring period.

[ method 3-3 for determining reference 2 ]

The UE may receive a set of control resources corresponding to: all QCL-type features of each control resource set are a subset of all QCL-type features of the specific control resource set determined by reference 1, connected to the control resource set that exists in the UE-specific search space within the corresponding PDCCH monitoring period.

[ method 3-4 for determining reference 2 ]

The UE may receive a set of control resources connected to a search space of the same type as the search space connected to the specific set of control resources, and the control resource sets present in the corresponding PDCCH monitoring period, all QCL-TypeD features of each set of control resources being a subset of all QCL-TypeD features of the specific set of control resources determined with reference to 1.

When considering method 3 of determining reference 2 in accordance with [ method 1-1 of determining reference 2 ] to [ method 3-4 of determining reference 2 ], if a reference control resource set is selected in consideration of [ method 1 of determining reference 1], if the number of different control resource sets that can be received in consideration of the same method of determining reference 3 (method 1 of determining reference 1) can be selected according to priority.

As described above, the UE may determine the priority when receiving the duplicate PDCCH transmission by a combination of the above-described various methods respectively applicable to references 1 to 3. The applicable method of each reference may be semi-statically configured by upper layer signaling from the base station, or may be dynamically indicated by L1 signaling, or may be configured and indicated by a combination of upper layer signaling and L1 signaling, or may use a fixed method determined by the standard. As an example of the combination of methods, [ method 1 of determining reference 1] may be applied to references 1 and 3, [ method 1-1 of determining reference 2 ] may be applied to reference 2. This will be described in more detail below with the example in fig. 21.

Fig. 21 is a flowchart illustrating a method of determining priority when receiving duplicate PDCCH transmissions, according to one embodiment of the present disclosure. In this example, a case of a total of eight control resource sets 2115 to 2150 overlapping in time of a total of three subcarriers 2100, 2105, and 2110 in a specific PDCCH monitoring period 2155 is considered. According to [ method 3 of determining reference 1], the reference control resource set conforming to reference 1 is the first control resource set in cc#1 connected to css#1 (e.g., may be named cc#1-css#1-c#1w 22115).

As an example, if the [ method 1-1 of determining reference 2 ] of fig. 21 is applied, since the UE may receive a control resource set connected to a common search space and a UE-specific search space while having the same number and type of QCL-type features as cc#1-css#1-c#1w2 within a corresponding PDCCH monitoring period, the UE may receive a first resource set connected to uss#1 (e.g., may be named as cc#2-uss#1-c#1w2 2130) and a first resource set connected to uss#1 in cc#3 and having the same two QCL-type features (e.g., may be named as cc#3-uss#1-c#1w2 2145) in cc#2.

As another example, if the [ method 2-3 of determining reference 2 ] in fig. 21 is applied, since the UE may receive a control resource set connected to the UE-specific search space while having at least one QCL-type feature of the same type as cc#1-css#1-c#1w2 within the corresponding PDCCH monitoring period, the UE may receive a third control resource set (e.g., may be named cc#1-uss2-c#3w1 2125) connected to uss#2 having the same first QCL-type feature as the reference control resource set, connected to uss#1 in cc#2, a second control resource set (e.g., may be named cc#2-uss#2w1 2135) having the same second QCL-type feature as the reference control resource set, connected to uss#1 in cc#2, a first control resource set (e.g., may be named cc#2-uss#2w1) having the same two l-type features as the reference control resource set, and may be named cc#2-c#2w1-uss#2 to uss#2 (e.g., may be named cc#2-c#2w1-2135), connected to uss#2-c#2-c#3w1 may be named as cc#2-2-USS 1).

At this time, if the maximum number of different control resource sets that can be received in the corresponding PDCCH monitoring period is 2, since the UE can select the reference control resource set as the first priority according to [ method 3 of determining reference 1 ], the control resource set regarded as the second priority is connected to USS, and there are two QCL-TypeD features, i.e., cc#2-uss#1-c#1w2 2130 and cc#3-uss#1-c#1w2 2145, the UE can receive cc#2-uss#1-c#1w2 2130 corresponding to the lower subcarrier index.

As another example, if the maximum number of different control resource sets that can be received in the corresponding PDCCH monitoring period is 3, since only the reference control resource set among the currently receivable control resource sets is connected to the common search space, since the control resource set regarded as the third priority is connected to USS in addition to the above two (reference control resource set and cc#2-uss#1-c#1w2 (2130)), and since there are a plurality of QCL-type features, i.e., cc#1-uss#1-c#3w1 2125 and cc#2-uss#2-c#2w1 2135, cc#1-uss#1-c#3w1 2125 and cc#2-uss#2w1 2135, the ue can receive cc#1-uss#1-c#3w1 2125 corresponding to the lower subcarrier index.

As another example, if the [ method 3-4 of determining reference 2 ] in fig. 21 is applied, since in the control resource set existing in the corresponding PDCCH monitoring period, the UE may receive a control resource set connected to the same type of search space as the search space to which the specific control resource set is connected and all QCL-type features of each control resource set are a subset of all QCL-type features of the specific control resource set determined by reference 1, the UE may receive a reference control resource set and a first control resource set (for example, may be named cc#2-css#1-c#1w2 2130) connected to css#1, having the same two QCL-type features, of cc#2.

Fig. 22A and 22B illustrate operations of a UE and a base station with respect to a method of determining priority when receiving duplicate PDCCH transmissions according to one embodiment of the present disclosure. The UE may report information related to PDCCH repetition transmission (e.g., at least one or part of a PDCCH repetition method, whether soft combining is possible, a possible level of soft combining, a necessary restriction of soft combining, etc.) as UE capabilities 2200 and 2250 to the base station. Further, the UE may report information (e.g., UE capabilities of at least one or a part of those listed in the fourth embodiment) regarding a method of determining priority when PDCCH retransmission is received as UE capabilities 2201 and 2251 to the base station.

The base station may receive this information and transmit configuration information of the PDCCH (e.g., configuration information on a control resource set and a search space) to the UEs 2202 and 2252, and the base station may additionally transmit configuration information related to repeated PDCCH transmission (e.g., a repeated transmission method, a number of repeated transmissions, a repeated transmission period, a PDCCH monitoring period assuming repeated transmission, a control resource set, a search space setting repeated transmission, etc.) to the UEs 2203 and 2253.

Further, the base station may additionally transmit explicit connection configuration related information (e.g., aggregation level, PDCCH candidate set, frequency resources, etc.) to the UE during repetition of PDCCH transmissions 2204 and 2254. If the base station sets a method based on a control resource set configured with a plurality of TCI states to the UE as a PDCCH retransmission method, information about explicit connection configuration during the repeated PDCCH transmission may not be transmitted from the base station to the UE. Further, the base station may additionally transmit configuration information (e.g., a maximum number of different QCL-types or number of control resource sets that may be received, a priority determination method, etc.) related to the priority determination method to the UE upon receiving the repeated PDCCH transmissions 2205 and 2255.

As described above, if the base station sets a method based on a control resource set in which a plurality of TCI states are configured in the PDCCH repetition transmission method to the UE, the base station may transmit a MAC-CE to activate the plurality of TCI states in the specific control resource sets 2206 and 2256. Then, based on the configuration information received from the base station, if there are no temporally overlapping control resource sets in the specific PDCCH monitoring periods 2207 and 2257, i.e., if there is only a single control resource set, the UE may perform first reception operations 2208 and 2258. The first reception operation may be a method of receiving a single control resource set existing in a corresponding PDCCH monitoring period. If there are a plurality of control resource sets overlapping in time in the specific PDCCH monitoring periods 2207 and 2257 and a plurality of TCI state control resource sets are not activated in the control resource sets 2209 and 2259, the UE may perform second reception operations 2210 and 2260.

The second reception operation may be a method of determining a priority of controlling the reception of the resource set in consideration of an operation of transmitting only a single PDCCH as the existing Rel-15/16. If there are a plurality of control resource sets overlapping in time in the specific PDCCH monitoring periods 2207 and 2257 and there are control resource sets 2209 and 2259 activating a plurality of TCI states in the control resource sets, the UE may perform third reception operations 2211 and 2261. The third reception operation may be a method of reception by combining the respective methods of references 1 to 3 in the above-described embodiment 4-1, and as an example, as described above, the UE may determine the priority at the time of reception of the duplicate PDCCH transmission by a combination of various methods applicable to each of references 1 to 3.

The applicable method of each reference may be semi-statically configured by upper layer signaling from the base station, or may be dynamically indicated by L1 signaling, may be configured and indicated by a combination of upper layer signaling and L1 signaling, or may use a fixed method determined by the standard. As an example of the method combination, [ method 1 of determining reference 1] may be applied to references 1 and 3, and [ method 1-1 of determining reference 2 ] may be applied to reference 2.

< example 4-2: priority determination method upon reception of PDCCH repeated transmission using control resource sets respectively connected to a plurality of explicitly-connected search spaces)

As one embodiment of the present disclosure, a method for determining a PDCCH reception priority when receiving PDCCH retransmission in a UE using control resource sets respectively connected to a plurality of explicitly connected search spaces will be described. If a plurality of control resource sets existing within a UE-activated bandwidth part of a single or a plurality of subcarriers overlap in time while having the same or different QCL-type characteristics within a specific PDCCH monitoring period, specifically, when at least one control resource set respectively connected to a plurality of search spaces for PDCCH repetition transmission configuration explicit connectivity is included within a corresponding PDCCH monitoring period, the UE may perform QCL priority operation in consideration of the following three references.

In one example of reference 1, a set of reference control resource sets is selected to determine whether each control resource set overlapping in time in a specific PDCCH monitoring section can be received.

In one example of reference 2, a control resource set simultaneously received in a specific PDCCH monitoring period is selected based on QCL-type characteristics included in the set of control resource sets selected in reference 1) above.

In considering the method of determining references 1 to 3, it may be assumed that there are one or more control resource sets that satisfy the following conditions during PDCCH monitoring for a plurality of subcarriers: multiple search spaces with explicit connectivity overlap in time with their respective associated control resource sets. For example, in the first subcarrier (cc#1), when the first to nth common search spaces (e.g., { css#1,., css#n }) have explicit connectivity to each other and overlap in time with the 1 st to nth control resource sets (e.g., { c#1,., c#n }) to which they are connected, respectively, in a specific PDCCH monitoring period, when the group corresponding control resource sets are described below, the period may be named "cc#1-CN/N { (css#1-c#1), (css#n-c#n) }. Here, CX/Y means that in the corresponding PDCCH monitoring period, all control resource sets respectively connected to Y search spaces having explicit connections overlap in total X control resource sets in time.

In this example, x=y=n. As another example, in the nth subcarrier (cc#n), when the second, third, and fifth UE-specific search spaces (e.g., { uss#2, uss#3, uss#5 }) have explicit connectivity with each other and the first to third control resource sets (e.g., { c#1, c#2, c#3 }) respectively connected thereto are overlapped in time within a specific PDCCH monitoring period, the group of control resource sets is named as "cc#n-C3/3{ (uss#2-c#1), (uss#3-c#2), and (uss#5-c#3) }. Here, C3/3 means that all three control resource sets connected to three search spaces each having explicit connectivity are overlapped in time within a corresponding PDCCH monitoring period.

As another example, in the mth subcarrier (cc#m), when the first and second UE-specific search spaces (e.g., { uss#1, uss#2 }) have explicit connectivity to each other, and only the first control resource set of the first and second control resource sets (e.g., { c#1, c#2 }) connected to each of them is overlapped in time within a specific PDCCH monitoring period, a set of control resource sets may be named "cc#m-C1/2{ (uss#1-c#1) and-! (USS#2-C#2) }. Here, C1/2 indicates that one of all control resource sets respectively connected to two search spaces with explicit connectivity overlaps in time in a corresponding PDCCH monitoring period. Unlike the first two examples, the expression used in the last example ≡ -! (-) may mean corresponding to! (.) the control resource set does not exist within a corresponding PDCCH monitoring period in the control resource set respectively connected to a plurality of search spaces having a plurality of search spaces with explicit interconnectivity. At-! (-), which may be a specific search space or control resource set, one of the candidates that may be (-), may be "USS #2-C #2". That is, it can be seen that the corresponding-! (.) the set of control resources is used for PDCCH repetition transmission in the TDM method and the set of control resources present in the corresponding monitoring period.

In contrast, in the above two examples, since there are all control resource sets respectively connected to a plurality of search spaces with explicit connectivity within the corresponding PDCCH monitoring period, it can be seen that all control resource sets are used for repeating PDCCH transmission in the FDM method. The corresponding naming scheme can be used only in example 4-2. Further, being determined as the following set of reference control resource sets means that, when a control resource set to be received in a corresponding PDCCH monitoring period to be determined in reference 2 is determined, a control resource set existing in the corresponding set of reference control resource sets can be determined based on the control resource set. Further, for a common search space and a UE-specific search space, if the first and second search spaces have explicit connectivity to each other, the first and second search spaces may have explicit connectivity to the other search space. Reference 1 may be determined in consideration of the following method.

[ method 1 for determining reference 1]

If the maximum number of multiple search spaces with explicit connectivity is N and each common search space and UE-specific search space within the active bandwidth portion of all subcarriers has the same N value, the UE may select a set of control resource sets that satisfy reference 1 according to the following order [ table 54 ]. The subcarrier index, the index of common and UE-specific search spaces, and the control resource set index are excluded in the naming scheme in the following order, and only CX/Y (whether common search space or UE-specific search space) representing the total number of control resource sets connected to a plurality of search space types with explicit connectivity is considered, Y and number X overlapping in the corresponding PDCCH monitoring period.

TABLE 54

When excluding the subcarrier index, the index of the common and UE-specific search space, and the control resource set index described above, the control resource set of the corresponding group may be understood as a group of a specific number of control resource sets respectively connected to the common or UE-specific search space, setting explicit connectivity for repeated PDCCH transmission. For example, CN/N { CSS-C } may be defined as a total of N control resource sets overlapping in time in the corresponding PDCCH monitoring period among all control resource sets connected to N common search spaces with explicit connectivity sets, while C1/2{ uss-C } may be defined as a total of one control resource set overlapping in time in the corresponding PDCCH monitoring period among all control resource sets connected to two UE-specific search spaces configured with explicit connectivity.

When there is at least one control resource set configuring a priority corresponding to any value shown in table 54 within the corresponding PDCCH monitoring period, a control resource set having the lowest index among the corresponding control resource set, the group of control resource sets having the lowest subcarrier index, and the plurality of explicitly connected common and UE-specific search spaces may be determined as the reference control resource set. For example, if there are two sets of control resource sets CN/N { CSS-C } (first and second control resource sets) corresponding to priority 1 in the table 54 within the corresponding PDCCH monitoring period, if the two control resource sets exist in the same subcarrier, the set of control resource sets (the first control resource set in this example) connected to the largest index search space may be regarded as a reference set of control resource sets by comparing the index of the lowest index common search space (e.g., CSS # 1) among the N common search spaces connected to the first control resource set and the common search space (e.g., CSS # 3) having the lowest index among the N common search spaces connected to the second control resource set.

Further, if there is no control resource set corresponding to the 1 st to nth priorities in the active bandwidth portion corresponding to all subcarriers within the PDCCH monitoring period, it is determined whether the group of control resource sets corresponding to the (n+1) th priorities exists the PDCCH monitoring period, and if there is at least one, the group of control resource sets that may be connected to the search space having the lowest subcarrier index among the corresponding control resource sets and the group of control resource sets that may be connected to the search space having the lowest index among the plurality of explicitly connected common and UE-specific search spaces may be determined as the reference control resource set.

[ method 2 for determining reference 1]

As another approach, the UE may follow the order of the following table 55 to determine the set of control resources that meets reference 1. Similar to the above [ method 1 of determining reference 1], the subcarrier index, the indices of common and UE-specific search spaces, and the control resource set index are excluded from the naming scheme in the following order, and only CX/Y (whether common search space or UE-specific search space) representing the total number of control resource sets connected to a plurality of search space types with explicit connectivity is considered, Y and number X overlapping in the corresponding PDCCH monitoring period.

TABLE 55

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According to table 55, in determining the set of reference control resource sets, the UE may prefer a set of control resource sets that may be determined based on control resource sets connected to multiple common search spaces with explicit connectivity over a set of control resource sets that may be based on control resource sets connected to multiple UE-specific search spaces with explicit connectivity. Further, the UE may select a set of control resource sets that may be determined based on control resource sets connected to multiple search spaces with explicit connectivity, rather than control resource sets connected to a single search space. Similar to [ method 1 of determining reference 1], if there is at least one control resource set configuring a priority corresponding to any value shown in [ table 55] in the corresponding PDCCH monitoring period, the UE may determine a control resource set having the lowest index among a group of control resource sets having the lowest subcarrier index, a plurality of explicitly connected common and UE-specific search spaces, which are connected to the search space, as the reference control resource set.

The [ method 3 of determining reference 1] to [ method 4 of determining reference 1] described below are methods corresponding to [ table 56] to [ table 57], respectively, and may be similar to [ table 54] or [ table 55] corresponding to the above-described [ method 1 of determining reference 1] or [ method 2 of determining reference 1 ]. Therefore, detailed descriptions of [ method 3 of determining reference 1] to [ method 4 of determining reference 1] which will be described later are omitted, and replaced with [ table 56] to [ table 57].

[ method 3 for determining reference 1]

As another approach, the UE may follow the order of table 56 below to determine the set of control resources that meets reference 1.

TABLE 56

[ method 4 for determining reference 1]

As another approach, the UE may follow the order of table 57 below to determine the set of control resources that meets reference 1.

TABLE 57

The [ method 1 of determining reference 1] to [ method 4 of determining reference 1] are only some examples, and another determination method not limited thereto may be used for reference 1. Further, referring to the UE capability of supporting the repeated PDCCH transmission for the above-described common search space in the above-described second embodiment, the UE and the base station may not support the repeated PDCCH transmission for the CSS. In this case, when considering the priority, the priority of the CSS repeated transmission in the consideration tables 54 to 57 may be ignored. More specifically, priorities 1 to N (n+1)/2-1 in tables 54 and 55 may be omitted, and odd number of priorities (e.g., 1, 3, 5,., N (n+1) -3) of priorities N (n+1) -1 are excluded in table 56, the priorities including the set of control resource sets connected to the CSS, but priorities other than priorities N (n+1) -1 (e.g., priorities 1 to N and 2n+1 to 3N, etc.).

From [ method 1 of determining reference 1] to [ method 4 of determining reference 1], the following method can be considered for the determination method of reference 2. The precondition for each of the methods described below is that the reference control resource set determined by [ method 1 for determining reference 1] to [ method 4 for determining reference 1] has M (1.ltoreq.M.ltoreq.N) QCL-TypeD characteristics.

[ method 1-1 for determining reference 2]

The UE may have the same number and type of QCL-type features as the reference set of the control resource sets determined by reference 1 in the corresponding PDCCH monitoring period and may receive the control resource sets connected to the common and UE-specific search spaces with explicit connectivity or connect to the control resource sets of one common and UE-specific search spaces without explicit connectivity using the corresponding QCL-type features.

[ methods 1-2 for determining reference 2]

The UE may have the same number and type of QCL-type features as the reference set of the control resource sets determined by reference 1 in the corresponding PDCCH monitoring period and may receive the control resource sets connected to the common search space with explicit connectivity or connect to the control resource sets of one common search space without explicit connectivity using the corresponding QCL-type features.

[ methods 1-3 for determining reference 2]

The UE may have the same number and type of QCL-type feature sets as the reference control resource sets determined by reference 1 in the corresponding PDCCH monitoring period, and may receive a control resource set connected to a UE-specific search space with explicit connectivity or a control resource set connected to one UE-specific search space with explicit connectivity using the corresponding QCL-type feature.

[ methods 1-4 for determining reference 2]

The UE may receive a control resource set connected to a search space having the same number, the same type of QCL-type characteristics, and the same type of search space as the specific search space set determined by reference 1, using the corresponding QCL-type characteristics within the corresponding PDCCH monitoring period.

[ method 2-1 for determining reference 2]

The UE may receive a control resource set connected to the common and UE-specific search space with explicit connectivity while having at least one QCL-type feature of the same type as a reference set of the control resource set determined with reference to 1 during a corresponding PDCCH monitoring period using a corresponding QCL-type feature, or to one common and UE-specific search space without explicit connectivity.

[ method 2-2 for determining reference 2]

The UE may receive a control resource set connected to common and UE-specific search spaces with explicit connectivity using corresponding QCL-type characteristics while having QCL-type characteristics of the same type as the reference control resource set determined by reference 1 in the corresponding PDCCH monitoring period, or to one common search space without explicit connectivity.

[ methods 2-3 for determining reference 2 ]

The UE may receive a control resource set connected to common and UE-specific search spaces with explicit connectivity using the corresponding QCL-type characteristics while having at least one QCL-type characteristic of the same type as the set of reference control resource sets determined with reference to 1 during the corresponding PDCCH monitoring period, or to one UE-specific search space without explicit connectivity.

[ method 2-4 for determining reference 2 ]

The UE may receive a set of control resources that satisfy the following conditions using the corresponding QCL-type feature: at least one QCL-type feature of the same type and search spaces of the same type are explicitly connected to a set of reference control resource sets determined by reference 1 in a corresponding PDCCH monitoring period, and each search space is connected; or receive a set of control resources connected to one search space of the same type that does not have explicit connectivity.

[ method 3-1 for determining reference 2]

The UE may receive a set of control resources corresponding to: among the control resource sets connected to common and UE-specific search spaces with explicit connectivity present in the corresponding PDCCH monitoring periods, all QCL-TypeD features of each control resource set are a subset of all QCL-TypeD features of the reference control resource set determined by reference 1; or receive a set of control resources connected to one common or UE-specific search space without explicit connectivity.

[ method 3-2 for determining reference 2]

The UE may receive a set of control resources corresponding to: among the control resource sets connected to a common specific search space with explicit connectivity existing within the corresponding PDCCH monitoring period, all QCL-TypeD features of each control resource set are a subset of all QCL-TypeD features of the reference control resource set determined by reference 1 above; or to a set of control resources connected to a common search space without explicit connectivity.

[ method 3-3 for determining reference 2]

The UE may receive a set of control resources corresponding to: among the control resource sets connected to the UE-specific search space with explicit connectivity present in the corresponding PDCCH monitoring period, all QCL-TypeD features of each control resource set are a subset of all QCL-TypeD features of the reference control resource set determined by reference 1; or receive a set of control resources connected to one UE-specific search space that does not have explicit connectivity.

[ method 3-4 for determining reference 2 ]

The UE may receive a set of control resources connected to a search space of the same type as the search space to which the configured set of reference control resources is connected, if: among the control resource sets connected to common and UE-specific search spaces with explicit connectivity present in the corresponding PDCCH monitoring periods, all QCL-TypeD features of each control resource set are a subset of all QCL-TypeD features of the reference control resource set determined by reference 1 above; or receive a set of control resources connected to one UE-specific search space without explicit connectivity.

In considering the method of determining reference 3, according to [ method 1-1 of determining reference 2 ] to [ method 3-4 of determining reference 2 ], if a reference control resource set is selected in consideration of [ method 1 of determining reference 1], for the same method of determining the method of reference 3 (method 1 of determining reference 1), if the maximum number of different control resource sets that can be received is limited, a limited control resource set can be selected according to priority.

As described above, the UE may determine the priority when receiving the duplicate PDCCH transmission by a combination of the above-described various methods respectively applicable to references 1 to 3. The applicable method of each reference may be semi-statically configured by upper layer signaling from the base station, or may be dynamically indicated by L1 signaling, or may be configured and indicated by a combination of upper layer signaling and L1 signaling, or may use a fixed method determined by the standard. As an example of the method combination, [ method 1 of determining reference 1] may be applied to references 1 and 3, and [ method 1-1 of determining reference 2 ] may be applied to reference 2. Examples will be described in more detail below with reference to fig. 23A and 23.

Fig. 23A and 23B illustrate operations of a UE and a base station with respect to a method of determining priority when receiving repeated PDCCH transmissions according to another embodiment of the present disclosure. The UE may report information related to repeated PDCCH transmissions (e.g., at least one or part of PDCCH repetition transmission methods, likelihood of soft combining, and necessary limitations of soft combining) as UE capabilities 2300 and 2350 to the base station.

Further, the UE may report information (e.g., at least one or a portion of the UE capabilities listed in the fourth embodiment) regarding the method of determining priority when receiving duplicate PDCCH transmissions as UE capabilities 2301 and 2351 to the base station. The base station may receive the information and transmit configuration information about the PDCCH (e.g., configuration information about a control resource set and a search space) to the UEs 2302 and 2352, and the base station may additionally transmit configuration information about repeated PDCCH transmission (e.g., a repeated transmission method, a number of repeated transmissions, a repeated transmission period, a PDCCH monitoring period assuming repeated transmission, a control resource set, a search space setting repeated transmission, etc.) to the UEs 2303 and 2353.

Further, the base station may additionally transmit explicit connection configuration related information (e.g., aggregation level, PDCCH candidate set, frequency resources, etc.) to the UE during repetition of PDCCH transmissions 2304 and 2354. In addition, the base station may also transmit configuration information (e.g., the maximum number of different QCL-types that may be received or the number of control resource sets, a priority determination method, etc.) related to the priority determination method to the UEs 2305 and 2355 upon receiving the PDCCH retransmission. Hereinafter, based on configuration information received from the base station, if there are no temporally overlapping control resource sets in the specific PDCCH monitoring periods 2306 and 2356, i.e., if there is only a single control resource set, the UE may perform the first reception operations 2307 and 2357. The first reception operation may be a method of receiving a single control resource set existing in a corresponding PDCCH monitoring period.

If there are a plurality of time-overlapping control resource sets in the specific PDCCH monitoring periods 2306 and 2356 and there is no control resource set connected to the search space having explicit connectivity among the control resource sets 2308 and 2358, the UE may perform the second reception operations 2309 and 2359. The second reception operation may be a method of determining a priority of controlling the reception of the resource set in consideration of an operation of transmitting only a single PDCCH as the existing Rel-15/16. If there are a plurality of time-overlapping control resource sets in the specific PDCCH monitoring periods 2306 and 2356 and there is at least one control resource set (2308, 2358) connected to the search space with explicit connectivity among the control resource sets, the UE may perform third reception operations 2310 and 2360.

The third reception operation is a reception method by combining each of the methods referenced 1 to 3 in the above-described embodiment 4-2. For example, as described above, the UE may determine the priority when receiving the duplicate PDCCH transmission by a combination of the above-described various methods respectively applicable to references 1 to 3. The applicable method of each reference may be semi-statically configured by upper layer signaling from the base station, or may be dynamically indicated by L1 signaling, or may be configured and indicated by a combination of upper layer signaling and L1 signaling, or may use a fixed method determined by the standard. As an example of the method combination, [ method 1 of determining reference 1] may be applied to reference 1 and reference 3, and [ method 1-1 of determining reference 2 ] may be applied to reference 2.

< examples 4-3: another method for prioritizing when receiving duplicate PDCCH transmissions using control resource sets respectively connected to multiple explicitly connected search spaces >

As one embodiment of the present disclosure, a method for determining QCL-type priority of a UE receiving a single and repeated PDCCH transmission at a specific monitoring occasion will be described. In addition to the above-described [ method 1 of determining reference 1] to [ method 4 of determining reference 1], other methods for determining reference 1 in embodiment 4-2 may be additionally considered as follows.

[ method 5 for determining reference 1]

When a plurality of control resource sets transmitted from a single or a plurality of subcarriers are time-overlapping at a specific monitoring occasion, the UE may select a control resource set connected to a common search space having a lowest index from among subcarriers in the common search space including the corresponding monitoring occasion and subcarriers corresponding to the lowest index. At this time, if the control resource sets overlapping at all times within the corresponding monitoring occasion are not connected to the common search space but connected to the UE-specific space, the UE may select a control resource set of a lowest index UE-specific search space among subcarriers corresponding to a lowest index among subcarriers of the UE-specific search space including the corresponding monitoring occasion. Here, the selected control resource set may be a control resource set conforming to reference 1. The above-described operations may not take into account explicit connections between multiple common search spaces or between multiple UE-specific search spaces. In addition to the control resource set derived as described above, in certain cases, another control resource set may be selected as the second reference in order to receive multiple QCL-type characteristics. At this time, the following detailed method can be considered.

Detailed method 5-1 this method can be used regardless of whether there is a search space with explicit connectivity to other search spaces in the search space connected to the first set of derived control resources. In addition to the search space connected to the first set of derived control resources, a set of control resources that is a second criterion may be derived by re-applying the above-described method of deriving the first set of control resources based on the remaining search space and the set of control resources connected to the search space.

Detailed method 5-2 when there is no search space explicitly connected to other search spaces among the search spaces connected to the first derivation control resource set, the control resource set as the second criterion may be derived by reapplying the above-described derivation method of deriving the first control resource set based on the remaining search spaces and the control resource set connected to the search spaces, in addition to the search space connected to the first derivation control resource set.

Detailed method 5-3 when a search space connected to a first set of derived control resources includes both a common search space and a UE-specific search space, if at least one common search space has explicit connectivity with other search spaces, among the common search spaces connected to the first set of derived control resources, a control resource set connected to a common search space having a lowest index among the common search spaces having explicit connectivity with other common search spaces may be pushed to be a control resource set used as a second reference.

For example, when the common search space 1, the common search space 2, and the UE-specific search space 1 exist as search spaces connected to the first derivation control resource set, the common search space 1 has explicit connectivity with the common search space 3, and the common search space 2 has explicit connectivity with the common search space 4, as described above, among the common search spaces 1 and 2 having explicit connectivity with other common search spaces, the control resource set connected to the common search space 1 having a low index and the common search space 3 having explicit connectivity may be derived as control resources as a second reference.

At this time, if the first and second derivation control resource sets are the same, i.e., different QCL-type features are one when two reference control resource sets are derived, the UE may derive a control resource set connected to a common search space having the next lowest index and a common search space having explicit connectivity as the second reference control resource set. In this way, N different reference control resource sets can be derived, and if N different reference control resource sets cannot be derived by the corresponding method, the remaining reference control resource sets can be derived using [ detailed method 5-1 ].

Detailed method 5-4 when a search space connected to a first set of deductive control resources includes both a common search space and a UE-specific search space, if there is no common search space with explicit connections to other search spaces and at least one UE-specific search space has an explicit connection, among the UE-specific search spaces connected to the first set of deductive control resources, among the search spaces with explicit connections to other UE-specific search spaces, a set of control resources connected to the UE-specific search space with the lowest index and the UE-specific search space with an explicit connection may be pushed to be a second set of reference control resources.

For example, when the common search space 1, the UE-specific search space 1, and the UE-specific search space 2 exist as search spaces connected to the first derivation control resource set, the UE-specific search space 1 has an explicit connection with the UE-specific search space 3, and the UE-specific search space 2 has an explicit connection with the UE-specific search space 4, the control resource set connected to the UE-specific search space 1 having a low index and the UE-specific search space 3 having an explicit connection may be pushed into the UE-specific search spaces 1 and 2 having an explicit connection with the other UE-specific search spaces described above, the second reference control resource set.

At this time, if the first and second derivation control resource sets are the same, i.e., when two reference control resource sets are derived, different QCL-type features are one, the UE may derive a control resource set connected to the UE-specific search space having the next lowest index and the UE-specific search space having explicit connectivity as the second reference control resource set. In this way, N different reference control resource sets can be derived, and if N different reference control resource sets cannot be derived by the corresponding method, the remaining reference control resource sets can be derived using [ detailed method 5-1 ].

The number of different QCL-types that can be deduced by [ detailed method 5-1] to [ detailed method 5-4] in the above [ method 5 of determining reference 1] may be N, which may be determined according to one of the following methods.

The value of N may be determined by upper layer signaling configuration. For example, if the upper layer signaling enabletwoduulttci-State is set, the value of N may be determined to be 2. As another example, the value of N may be determined by new upper layer signaling for duplicate PDCCH transmissions.

Regardless of the overlapping control resource sets on the respective monitoring occasions, N may be considered as the maximum of the number of search spaces that set explicit connectivity for all subcarriers in a particular frequency band (e.g., if two search spaces are explicitly connected on subcarrier 1 and three search spaces are explicitly connected on subcarrier 2, N may be 3).

When some of the overlapping control resource sets on the corresponding monitoring occasions are respectively connected to the search spaces explicitly connected to each other for PDCCH repetition transmission, N may be determined according to the number of the explicitly connected search spaces. N may be considered to be 2 if the two search spaces are explicitly connected and the sets of control resources respectively connected to the two search spaces overlap in time on the corresponding monitoring occasions. If all overlapping sets of control resources are connected to a single search space, but not explicitly connected to the connected search space, N may be considered a 1.

According to the value of N determined by one of the above methods, if the set of reference control resources derived by one of the above-described [ method 1 of determining reference 1] to [ method 5 of determining reference 1] is smaller than N, the UE may use one of the above-described [ method 1 of determining reference 1] to [ method 5 of determining reference 1] until N sets of reference control resources are derived. Furthermore, if N sets of reference control resources are derived by the above-described [ method 1 of determining reference 1] to [ method 5 of determining reference 1], the process of [ method 1 of determining reference 1] to [ method 5 of determining reference 1] may terminate at this point. For example, when [ method 5 of determining reference 1] is used as a method of deriving the reference control resource set, if the value of N is 1, the process of selecting the second control resource set may be performed without selecting one of the methods after selecting the first control resource set, [ detailed method 5-1] to [ detailed method 5-4 ].

Further, the UE may report the UE capability of the method to the base station, and the above-described [ method 5 of determining reference 1] is similar to the above-described [ method 1 of determining reference 1] to [ method 4 of determining reference 1], the method of determining reference 1 being performed in the third receiving operations 2310 and 2360 in fig. 23A and 23B.

Fig. 24 illustrates a structure of a UE in a wireless communication system according to one embodiment of the present disclosure.

Referring to fig. 24, the UE may include a transceiver, a memory (not shown), and a UE processor 2405 (or a UE control unit or processor) referring to a UE receiver unit 2400 and a UE transmitter 2410. According to the above-described communication method of the UE, the transceivers 2400 and 2410, the memory and the UE processor 2405 of the UE may be operated. However, the components of the UE are not limited to the above examples. For example, the UE may include more or less components than those described above. In addition, the transceiver, the memory, and the processor may be implemented in one chip.

The transceiver may transmit information to and receive signals from the base station. Here, the signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low noise amplifying and down-converting the received signal. However, this is merely an exemplary embodiment of a transceiver and the components of a transceiver are not limited to RF transmitters and RF receivers.

Further, the transceiver may receive a signal through a wireless channel and output it to the processor, and transmit the signal output from the processor through the wireless channel.

The memory may store programs and data required for the UE operation. Further, the memory may store control information or data included in signals transmitted and received by the UE. The memory may be configured as a storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM, and DVD. Furthermore, there may be a plurality of memories.

Further, the processor may control a series of processes so that the UE may operate according to the above-described embodiments. For example, the processor may receive DCI composed of two layers and control components of the UE to simultaneously receive multiple PDSCH. The number of processors may be plural, and the processors may perform component control operations of the UE by executing programs stored in the memory.

Referring to fig. 25, a base station may include transceivers, memory (not shown), and a base station processor 2505 (or base station controller or processor), referring to a base station receiver 2500 and a base station transmitter 2510. The base station transceivers 2500 and 2510, memory and base station processor 2505 may be operated in accordance with the base station communication methods described above. However, the components of the base station are not limited to the above examples. For example, a base station may include more or less components than those described above. In addition, the transceiver, memory, and processor may be implemented in a single chip.

The transceiver may transmit information to/receive signals from the UE. Here, the signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low noise amplifying and down-converting the received signal. However, this is merely an embodiment of a transceiver, and the components of a transceiver are not limited to RF transmitters and RF receivers.

The memory may store programs and data required for operation of the base station. Further, the memory may store control information or data included in signals transmitted and received by the base station. The memory may be configured as a storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM, and DVD. Furthermore, there may be a plurality of memories.

According to the foregoing embodiments of the present disclosure, the processor may control a series of procedures to operate the base station. For example, the processor may control each component of the base station to configure two layers of DCI, including allocation information on multiple PDSCH and transmit the information. The number of processors may be plural, and the processors may execute programs stored in the memory to perform component control operations of the base station.

The methods according to the various embodiments described in the claims or specification of the present disclosure may be implemented by hardware, software, or a combination of hardware and software.

When the methods are implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors within the electronic device. The at least one program may comprise instructions that cause an electronic device to perform a method according to embodiments of the present disclosure as defined in the appended claims and/or disclosed herein.

Programs (software modules or software) may be stored in non-volatile memory, including random access memory and flash memory, read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disk storage, magnetic disk-ROM (CD-ROM), digital Versatile Disks (DVD), or other types of optical storage or magnetic tape. Alternatively, any combination of some or all of them may form a memory storing a program. Furthermore, a plurality of these memories may be included in the electronic device.

Further, the program may be stored in an attachable storage device that may access the electronic device through a communication network such as the internet, an intranet, a Local Area Network (LAN), a wide area network (WLAN), and a Storage Area Network (SAN), or a combination thereof. The storage devices may access the electronic device through external ports. Further, a separate storage device on the communication network may access the portable electronic device.

In the above detailed embodiments of the present disclosure, elements included in the present disclosure are indicated in the singular or plural depending on the detailed embodiment presented. However, the singular or plural forms are appropriately selected depending on the presented case for convenience of description, and the present disclosure is not limited to the elements expressed in the singular or plural. Accordingly, an element expressed in a plurality of numbers may include a single element, or an element expressed in a singular may include a plurality of elements.

The embodiments of the present disclosure described and illustrated in the present specification and drawings are presented merely for the purpose of facilitating explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is apparent to those skilled in the art that other modifications and alterations can be made to the present disclosure on the basis of the technical ideas. Further, the above embodiments may be used in combination as needed. For example, portions of one embodiment of the present disclosure may be combined as part of any other embodiment to operate a base station and a terminal. As an example, part of embodiment 1 and part of embodiment 2 may be combined together to operate a base station and a terminal. Further, although the above-described embodiments have been described by the FDD LTE system, other variations based on the technical ideas of the embodiments may be implemented in other systems such as TDD LTE, 5G, or NR systems.

In the drawings describing the methods of the present disclosure, the order described does not always correspond to the order in which the steps of each method are performed, and the order relationship between the steps may be changed or the steps may be performed in parallel.

Alternatively, in the drawings describing the method of the present disclosure, certain elements may be omitted and only certain elements included therein without departing from the basic spirit and scope of the present disclosure.

Further, in the methods of the present disclosure, some or all of the contents of each embodiment may be combined without departing from the basic spirit and scope of the disclosure.

Various embodiments of the present disclosure have been described above, but these implementations are for illustration purposes only and embodiments of the present disclosure are not limited to the embodiments set forth herein. It will be understood by those skilled in the art that other specific modifications and changes may be readily made thereto without changing the technical spirit or essential features of the present disclosure. The scope of the present disclosure is not to be determined by the above detailed description but by the appended claims, and all changes and modifications derived from the meaning and scope of the claims and their equivalents should be construed as falling within the scope of the present disclosure.

While the present disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. The disclosure is intended to embrace alterations and modifications that fall within the scope of the appended claims.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising:

receiving a Radio Resource Control (RRC) message from a base station, the Radio Resource Control (RRC) message including configuration information regarding a plurality of Search Spaces (SSs);

identifying a first set of control resources (CORESET) corresponding to a first SS of the plurality of SSs having a lowest index;

identifying one or more SSs by excluding one or more first SSs associated with the first CORESET from the plurality of SSs;

identifying at least one of the one or more SSs that is linked to one of the one or more first SSs;

identifying a second CORESET corresponding to a second SS having a lowest index of the at least one SS; and

physical Downlink Control Channels (PDCCHs) are monitored in overlapping PDCCH monitoring occasions in the first core and the second core.

2. The method of claim 1, wherein identifying the at least one SS comprises:

Identifying at least one common SS (CSS) linked to one of the one or more first SSs; and

identifying at least one user equipment specific SS (USS) linked to one of the one or more first SSs in the absence of the at least one CSS,

wherein the at least one SS corresponds to the at least one USS,

wherein the plurality of SSs corresponds to one of CSS or USS, and

wherein PDCCH monitoring opportunities of the plurality of SSs overlap in time resources.

3. The method according to claim 2,

wherein the PDCCH is monitored in the first CORESET in the absence of the at least one USS.

4. The method according to claim 1,

wherein the first CORESET is configured with a first quasi co-located (QCL) type D characteristic,

wherein the second CORESET is configured with a second QCL type D characteristic, an

Wherein the first QCL type D characteristic is different from the second QCL type D characteristic.

5. The method of claim 1, further comprising:

transmitting User Equipment (UE) capability information to the base station, the UE capability information including information about the number of quasi co-located (QCL) type D features simultaneously supported by the terminal,

Wherein the RRC message further includes information indicating simultaneous reception of using a plurality of different QCL type D characteristics to a plurality of CORESET applications overlapping in time resources.

6. A terminal in a wireless communication system, the terminal comprising:

a transceiver configured to transmit and receive signals; and

a processor coupled to the transceiver, wherein the processor is configured to:

identifying a second CORESET corresponding to a second SS having a lowest index of the at least one SS; and is also provided with

Physical Downlink Control Channels (PDCCHs) are monitored in overlapping PDCCH monitoring occasions in the first CORESET and the second CORESET.

7. The terminal of claim 6, wherein the processor is further configured to:

identifying at least one common SS (CSS) linked to one of the one or more first SSs; and is also provided with

wherein the at least one SS corresponds to the at least one USS,

wherein the plurality of SSs corresponds to one of CSS or USS, and

8. The terminal according to claim 7,

9. The terminal according to claim 6,

10. The terminal of claim 6, wherein the processor is further configured to:

11. A method performed by a base station in a wireless communication system, the method comprising:

transmitting a Radio Resource Control (RRC) message to the terminal, the Radio Resource Control (RRC) message including configuration information regarding a plurality of Search Spaces (SSs);

a Physical Downlink Control Channel (PDCCH) is transmitted to the terminal in an overlapping PDCCH monitoring occasion of the first CORESET and the second CORESET.

12. The method of claim 11, wherein identifying the at least one SS comprises:

wherein the at least one SS corresponds to the at least one USS,

wherein the plurality of SSs corresponds to one of CSS or USS, and

13. The method according to claim 12,

wherein the PDCCH is transmitted in the first CORESET in the absence of the at least one USS.

14. The method according to claim 11,

15. The method of claim 11, further comprising:

receiving User Equipment (UE) capability information from the terminal, the UE capability information including information about the number of quasi co-located (QCL) type D features supported simultaneously by the terminal,