WO2025009864A1 - Method and apparatus for repeater using plurality of passbands in wireless communication system - Google Patents

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Specifically, a method performed by a network-controlled repeater (NCR) of a wireless communication system comprises the steps of: transmitting, to a base station, capability information for a passband supportable by the NCR; and receiving, from the base station, higher layer signaling including configuration information for the passband, wherein the passband is a band including a backhaul and/or an access link of the NCR, and the capability information includes a band number for one or more passbands, at least one piece of frequency band resource information, and inter-band capability information and/or intra-band capability information of the NCR.

Description

Method and device for repeater utilizing multiple passbands in wireless communication system

The present disclosure relates to a communication method and device using a network control repeater for signal relay between a terminal and a base station in a wireless communication system.

5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band, such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (㎜Wave), such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low delay time that is reduced by one-tenth.

In the early stages of 5G mobile communication technology, the goal was to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). The technologies included beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2 Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

Currently, discussions are underway on improving and enhancing the initial 5G mobile communication technology in consideration of the services that the 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

In addition, standardization of wireless interface architecture/protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) to provide nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step RACH for NR to simplify random access procedures is also in progress, and standardization of system architecture/services for 5G baseline architecture (e.g. Service based Architecture, Service based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal is also in progress.

When such 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, which will require enhanced functions and performance of 5G mobile communication systems and integrated operation of connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, AI service support, metaverse service support, drone communications, etc. using extended reality (XR), artificial intelligence (AI), and machine learning (ML) to efficiently support augmented reality (AR), virtual reality (VR), and mixed reality (MR).

In addition, the development of these 5G mobile communication systems will require new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, and AI (Artificial Intelligence) from the design stage and AI-based communication technology that implements end-to-end AI support functions to realize system optimization, and ultra-high-performance communication and computing resources to provide services with a level of complexity that goes beyond the limits of terminal computing capabilities. It could serve as a basis for the development of next-generation distributed computing technologies that utilize this.

Currently, a network-controlled repeater (NCR) is being studied to control interference and increase the reliability of signal transmission and processing through signal relay between base stations and terminals in wireless communication systems.

The present disclosure provides a method and device for applying multiple passbands in a network-controlled repeater (NCR) that processes signal relay between a base station and a terminal in a wireless communication system.

In order to solve the above problems, the present invention provides a method performed by an NCR (network-controlled repeater) of a wireless communication system, comprising: a step of transmitting capability information on a passband that the NCR can support to a base station; and a step of receiving, from the base station, upper layer signaling including configuration information on the passband, wherein the passband is a band including a backhaul or/and an access link of the NCR, and the capability information includes at least one of a band number and frequency band resource information for one or more passbands and inter-band capability information or/and intra-band capability information of the NCR.

Also, in a method performed by a base station of a wireless communication system, the method comprises the steps of: receiving capability information on a passband that can be supported by an NCR (network-controlled repeater); and transmitting upper layer signaling including configuration information on the passband to the NCR, wherein the passband is a band including a backhaul or/and an access link of the NCR, and the capability information includes at least one of a band number and frequency band resource information for one or more passbands and inter-band capability information or/and intra-band capability information of the NCR.

Also, in a network-controlled repeater (NCR) of a wireless communication system, the NCR comprises: a transceiver; and a control unit configured to transmit capability information on a passband that the NCR can support to a base station and receive upper layer signaling including configuration information on the passband from the base station, wherein the passband is a band including a backhaul or/and an access link of the NCR, and the capability information includes at least one of a band number and frequency band resource information for one or more passbands and inter-band capability information or/and intra-band capability information of the NCR.

In addition, in a base station of a wireless communication system, a transceiver; and a control unit configured to receive capability information on a passband that can be supported by an NCR (network-controlled repeater) from the NCR, and transmit upper layer signaling including configuration information on the passband to the NCR, wherein the passband is a band including a backhaul or/and an access link of the NCR, and the capability information includes at least one of a band number and frequency band resource information for one or more passbands and inter-band capability information or/and intra-band capability information of the NCR.

According to various embodiments proposed in the present disclosure, if a base station in a wireless communication system can perform frequency-selective amplification and transmission operations through control signaling, the effects of interference reduction and power consumption reduction can be obtained. In addition, if the NCR operates simultaneously in FR1 and FR2, performance and reliability can be increased.

Figure 1 is a diagram illustrating a time-frequency domain transmission structure of an LTE, LTE-Advanced, NR, or similar wireless communication system.

Figure 2 is a diagram illustrating the frame, subframe, and slot structure in a 5G system.

Figure 3 is a diagram illustrating an example of a bandwidth portion configuration in a wireless communication system.

Figure 4 is a diagram illustrating the structure of a downlink control channel of a wireless communication system.

FIG. 5 is a diagram illustrating an example of the structure of a downlink control channel of a wireless communication system.

Figure 6 is a diagram illustrating an example of time domain resource allocation of PDSCH in a wireless communication system.

Figure 7 is a diagram illustrating an example of PDSCH time axis resource allocation in a wireless communication system.

FIG. 8 is a diagram illustrating an example of a method for setting a semi-static HARQ (hybrid automatic repeat request)-ACK (acknowledgement) codebook in an NR system.

Figure 9 is a diagram illustrating an example of a method for setting a dynamic HARQ-ACK codebook in an NR system.

FIG. 10 is a diagram illustrating an example of a transmission and reception operation of an NCR when the NCR relays between a base station and a terminal according to an embodiment of the present disclosure.

FIG. 11A is a diagram illustrating an example of an NCR receiving beam instructions for a periodic access link from a base station according to one embodiment of the present disclosure.

FIG. 11b is a diagram illustrating an example of an NCR receiving beam instructions for a semi-persistent access link from a base station according to one embodiment of the present disclosure.

FIG. 11c is a diagram illustrating an example of an NCR receiving a beam instruction for an aperiodic access link from a base station according to an embodiment of the present disclosure.

FIG. 12 is a diagram illustrating an example of an NCR-MT band and passband according to one embodiment of the present disclosure.

FIG. 13 is a diagram illustrating an example of a capability report of an NCR including passband information according to an embodiment of the present disclosure.

FIG. 14 is a diagram illustrating an example of setting a passband and an access link beam index according to an embodiment of the present disclosure.

FIG. 15 is a diagram illustrating an example of an independent passband indication according to one embodiment of the present disclosure.

FIG. 16 is a flowchart illustrating an example of the operation of an NCR performing at least one embodiment of the present disclosure.

FIG. 17 is a flowchart illustrating an example of the operation of a base station performing at least one embodiment of the present disclosure.

FIG. 18 is a block diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

FIG. 19 is a block diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

FIG. 20 is a block diagram illustrating the structure of an NCR in a wireless communication system according to an embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present disclosure belongs and are not directly related to the present disclosure will be omitted. This is to convey the gist of the present disclosure more clearly without obscuring it by omitting unnecessary descriptions.

For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. The same or corresponding components in each drawing are given the same reference numbers.

The advantages and features of the present disclosure, and the methods for achieving them, will become apparent by referring to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and the embodiments of the present disclosure are provided only to make the present disclosure complete and to fully inform those skilled in the art of the scope of the invention, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce an article of manufacture that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may also be installed on a computer or other programmable data processing apparatus, the instructions that cause a series of operational steps to be performed on the computer or other programmable data processing apparatus to produce a computer-implemented process, so that the computer or other programmable data processing apparatus may also provide steps for executing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a particular logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order, depending on the functionality they perform.

Here, the term '~ part' used in the present embodiment means software or hardware components such as FPGA (field programmable gate array) or ASIC (application specific integrated circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be in an addressable storage medium and may be configured to play one or more processors. Accordingly, according to some embodiments, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. In addition, the components and '~parts' may be implemented to regenerate one or more CPUs within the device or secure multimedia card. Also, according to some embodiments, the '~part' may include one or more processors.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the attached drawings. In the following description of the present invention, if it is judged that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present invention, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification. Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (base station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (user equipment), an MS (mobile station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Of course, the present invention is not limited to the above examples. Hereinafter, the present disclosure describes a technology for a terminal to receive broadcast information from a base station in a wireless communication system. The present disclosure relates to a communication technique and system for fusing a 5G ( ^5th generation) communication system for supporting a higher data transmission rate than a 4G ( ^4th generation) system with IoT (internet of things) technology. The present disclosure can be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology.

In the following description, terms referring to broadcast information, terms referring to control information, terms related to communication coverage, terms referring to state changes (e.g., events), terms referring to network entities, terms referring to messages, terms referring to device components, etc. are examples for convenience of explanation. Therefore, the present invention is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

For the convenience of the following explanation, some of the terms and names defined in the 3GPP (3rd generation partnership project) LTE (long term evolution) standard and NR (New radio) standard may be used. However, the present invention is not limited to the above terms and names, and may be equally applied to systems that comply with other standards.

Wireless communication systems are evolving from providing initial voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

In the LTE system, which is a representative example of a broadband wireless communication system, the downlink (DL) adopts the OFDM (orthogonal frequency division multiplexing) method, and the uplink (UL) adopts the SC-FDMA (single carrier frequency division multiple access) method. The uplink refers to a wireless link in which a terminal or MS transmits data or a control signal to a base station, and the downlink refers to a wireless link in which a base station transmits data or a control signal to a terminal. The above multiple access method allocates and operates the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so that orthogonality is established, thereby distinguishing the data or control information of each user.

As a future communication system after LTE, that is, the 5G communication system must be able to freely reflect various requirements of users and service providers, and therefore services that satisfy various requirements must be supported. Services considered for the 5G communication system include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra reliability low latency communication (URLLC).

In some embodiments, eMBB aims to provide a data transmission rate that is further improved than that supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, eMBB should be able to provide a peak data rate of 20 Gbps in downlink and a peak data rate of 10 Gbps in uplink from the perspective of one base station. At the same time, it should provide an increased user perceived data rate. To satisfy such requirements, improvements in transmission and reception technologies, including further improved multi-input multi-output (MIMO) transmission technologies, are required. In addition, the data transmission rate required by the 5G communication system can be satisfied by using a frequency bandwidth wider than 20 MHz in a frequency band of 3 to 6 GHz or higher than 6 GHz instead of the 2 GHz band used by the current LTE.

At the same time, mMTC is being considered to support application services such as the Internet of Things in 5G communication systems. In order to efficiently provide the Internet of Things, mMTC may require support for connection of large numbers of terminals within a cell, improved coverage of terminals, improved battery life, and reduced cost of terminals. Since the Internet of Things provides communication functions by attaching various sensors and various devices, it should be able to support a large number of terminals (e.g., 1,000,000 terminals/ ^km2 ) within a cell. In addition, terminals supporting mMTC are likely to be located in shadow areas that cells do not cover, such as basements of buildings, due to the nature of the service, and thus may require wider coverage than other services provided by 5G communication systems. Terminals supporting mMTC should be composed of low-cost terminals, and since it is difficult to frequently replace the terminal batteries, very long battery life times may be required.

Finally, for URLLC, as a mission-critical cellular-based wireless communication service, such as remote control of robots or machinery, industrial automation, unmanaged aerial vehicles, remote health care, and emergency alert, it must provide ultra-low latency and ultra-reliable communication. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and at the same time has a packet error rate requirement of less than 10 ^-5 . Therefore, for a service supporting URLLC, the 5G system must provide a smaller transmit time interval (TTI) than other services, and at the same time, the design requirements of allocating wide resources in the frequency band are required. However, the above-mentioned mMTC, URLLC, and eMBB are only examples of different service types, and the service types to which the present disclosure applies are not limited to the above-mentioned examples.

The services considered in the 5G communication system mentioned above should be provided by being integrated with each other based on a single framework. In other words, for efficient resource management and control, it is desirable that each service be controlled and transmitted as an integrated system rather than operated independently.

In addition, although the embodiments of the present disclosure are described below using LTE, LTE-A, LTE Pro or NR systems as examples, the embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. In addition, the embodiments of the present disclosure may be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure as judged by a person having skilled technical knowledge.

Below, the frame structure of the 5G system is described in more detail with reference to the drawings.

Figure 1 is a diagram illustrating an example of the basic structure of time-frequency resources of a wireless communication system.

(일례로 12)개의 연속된 RE들은 하나의 자원 블록(resource block, RB, 1-04)을 구성할 수 있다. 일 실시 예에서, 복수 개의 OFDM 심볼들은 하나의 서브프레임(subframe, 1-10)을 구성할 수 있다.Referring to Figure 1, the horizontal axis in Figure 1 represents the time domain and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 1-01), which can be defined as 1 OFDM symbol (1-02) on the time axis and 1 subcarrier (1-03) on the frequency axis. In the frequency domain,

(For example, 12) consecutive REs can form one resource block (RB, 1-04). In one embodiment, multiple OFDM symbols can form one subframe (subframe, 1-10).

FIG. 2 is a diagram illustrating an example of a frame, subframe, and slot structure of a wireless communication system.

)=14). 1 서브프레임(2-01)은 하나 또는 다수 개의 슬롯(2-02, 2-03)으로 구성될 수 있으며, 1 서브프레임(2-01)당 슬롯(2-02, 2-03)의 개수는 부반송파 간격에 대한 설정 값 μ(2-04, 2-05)에 따라 다를 수 있다. 도 2의 일례에서는 부반송파 간격 설정 값으로 μ=0(2-04)인 경우와 μ=1(2-05)인 경우가 도시되어 있다. μ=0(2-04)일 경우, 1 서브프레임(2-01)은 1개의 슬롯(2-02)으로 구성될 수 있고, μ=1(2-05)일 경우, 1 서브프레임(2-01)은 2개의 슬롯(2-03)으로 구성될 수 있다. 즉 부반송파 간격에 대한 설정 값 μ에 따라 1 서브프레임 당 슬롯 수(

)가 달라질 수 있고, 이에 따라 1 프레임 당 슬롯 수(

)가 달라질 수 있다. 각 부반송파 간격 설정 μ에 따른

및

는 하기의 표 1과 같이 정의될 수 있다.Referring to FIG. 2, one frame (frame, 2-00) may be composed of one or more subframes (2-01), and one subframe may be composed of one or more slots (slots, 2-02). For example, one frame (2-00) may be defined as 10ms. One subframe (2-01) may be defined as 1ms, in which case one frame (2-00) may be composed of a total of 10 subframes (2-01). One slot (2-02, 2-03) may be defined as 14 OFDM symbols (i.e., the number of symbols per slot (

)=14). 1 subframe (2-01) may be composed of one or more slots (2-02, 2-03), and the number of slots (2-02, 2-03) per 1 subframe (2-01) may vary depending on the setting value μ (2-04, 2-05) for the subcarrier spacing. In the example of Fig. 2, the cases where the subcarrier spacing setting value μ = 0 (2-04) and μ = 1 (2-05) are illustrated. When μ = 0 (2-04), 1 subframe (2-01) may be composed of one slot (2-02), and when μ = 1 (2-05), 1 subframe (2-01) may be composed of two slots (2-03). In other words, the number of slots (

) may vary, and accordingly the number of slots per frame (

) may vary. Depending on the subcarrier spacing setting μ

and

can be defined as shown in Table 1 below.

μ

0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16 5 14 320 32

In the NR system, a single component carrier (CC) or serving cell can consist of up to 250 RBs. Therefore, if a terminal always receives the entire serving cell bandwidth like LTE, the power consumption of the terminal can be extreme. To solve this problem, the base station can support the terminal to change the reception area within the cell by setting one or more bandwidth portions (BWPs) to the terminal.

In the NR system, a base station can set an initial bandwidth part (initial BWP), which is a bandwidth of a control resource set (CORESET) #0 (or a common search space (CSS)), to a terminal through a master information block (MIB). Specifically, in the initial access phase, the terminal can receive configuration information about a control region and a search space on which a physical downlink control channel (PDCCH) can be transmitted, in order to receive system information required for initial access (which may correspond to remaining system information (RMSI) or system information block 1 (SIB1)) through the MIB transmitted on a physical broadcast channel (PBCH). The control region and the search space set by the MIB can each be regarded as identifier (identity, ID) 0.

The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for the control area #0 through the MIB. In addition, the base station can notify the terminal of configuration information for the monitoring period and occasion for the control area #0, that is, configuration information for the search space #0, through the MIB. The terminal can regard the frequency area set as the control area #0 obtained from the MIB as an initial bandwidth part for initial access. At this time, the identifier (ID) of the initial bandwidth part can be regarded as 0. In addition to the purpose of receiving the SIB, the initial bandwidth part can also be utilized for other system information (OSI), paging, and random access.

Thereafter, the base station can set the initial BWP (first BWP) of the terminal through RRC (radio resource control) signaling, and can notify at least one or more BWP configuration information that can be indicated through downlink control information (DCI) in the future. Afterwards, the base station can indicate which band the terminal will use by notifying the BWP ID through DCI. If the terminal does not receive the DCI in the currently allocated BWP for a certain period of time, the terminal reverts to the default bandwidth part (default BWP) and attempts to receive the DCI.

FIG. 3 is a diagram illustrating an example of a bandwidth part (BWP) configuration in a wireless communication system.

Referring to FIG. 3, FIG. 3 illustrates an example in which a terminal bandwidth (3-00) is set to two bandwidth parts, namely, bandwidth part #1 (3-05) and bandwidth part #2 (3-10). A base station can set one or more bandwidth parts to a terminal, and can set information such as Table 2 below for each bandwidth part.

BWP ::= SEQUENCE {
bwp-Id BWP-Id,
(bandwidth part identifier)
locationAndBandwidth INTEGER (1..65536);
(Bandwidth part location)
subcarrierSpacing ENUMERATED {n0, n1, n2, n3, n4, n5},
(subcarrier spacing)
cyclicPrefix ENUMERATED { extended }
(cyclic preposition)
}

Of course, it is not limited to the above-described examples, and in addition to the above-described configuration information, various parameters related to the bandwidth portion may be set for the terminal. The above-described information may be transmitted from the base station to the terminal via upper layer signaling, for example, RRC signaling. At least one bandwidth portion among the configured one or more bandwidth portions may be activated. Whether or not the configured bandwidth portion is activated may be semi-statically transmitted from the base station to the terminal via RRC signaling, or dynamically transmitted via MAC (medium access control) CE (control element) or DCI.

The settings for the bandwidth part supported by the above-described NR system can be used for various purposes.

For example, in a case where the bandwidth supported by the terminal is smaller than the system bandwidth, the bandwidth supported by the terminal can be supported through settings for the bandwidth portion. For example, in Table 2, by setting the frequency position (setting information 2) of the bandwidth portion to the terminal, the terminal can transmit and receive data at a specific frequency position within the system bandwidth.

As another example, in order to support different numerologies, a base station may set multiple bandwidth portions to a terminal. For example, in order to support both data transmission and reception using a subcarrier spacing of 15 kHz and a subcarrier spacing of 30 kHz for a given terminal, two bandwidth portions may be set to use subcarrier spacings of 15 kHz and 30 kHz, respectively. The different bandwidth portions may be FDM (frequency division multiplexed), and when data is to be transmitted or received using a specific subcarrier spacing, the bandwidth portion set to the corresponding subcarrier spacing may be activated.

As another example, for the purpose of reducing power consumption of the terminal, the base station can set a bandwidth portion having a different size of bandwidth to the terminal. For example, if the terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz, and always transmits and receives data with the bandwidth, it can cause very large power consumption. In particular, in a situation where there is no traffic, it is very inefficient in terms of power consumption for the terminal to perform monitoring of unnecessary downlink control channels for a large bandwidth of 100 MHz. Therefore, in order to reduce power consumption of the terminal, the base station can set a bandwidth portion having a relatively small bandwidth, for example, a bandwidth portion of 20 MHz, to the terminal. In a situation where there is no traffic, the terminal can perform a monitoring operation in the bandwidth portion of 20 MHz, and when data is generated, it can transmit and receive data using the bandwidth portion of 100 MHz according to the instructions of the base station.

Below, the SS (synchronization signal)/PBCH block (or SSB (synchronization signal block)) of the NR system is described.

An SS/PBCH block may mean a physical layer channel block consisting of a PSS (primary SS), an SSS (secondary SS), and a PBCH. More specifically, an SS/PBCH block may be defined as follows.

- PSS: A signal that serves as a reference for downlink time/frequency synchronization and can provide some information about the cell ID.

- SSS: It serves as a reference for downlink time/frequency synchronization and can provide the remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for demodulation of PBCH.

- PBCH: It can provide essential system information required for transmission and reception of data channels and control channels of the terminal. Essential system information can include search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel transmitting system information, etc.

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

The terminal can detect PSS and SSS in the initial access stage, and decode PBCH. The terminal can obtain MIB from PBCH, and set control region #0 through MIB. The terminal can monitor control region #0 assuming that the selected SS/PBCH block and DMRS (demodulation reference signal) transmitted in control region #0 are QCL (quasi co-located). The terminal can receive system information through downlink control information transmitted in control region #0. The terminal can obtain RACH (random access channel) related configuration information required for initial access from the received system information. The terminal can transmit PRACH (physical RACH) to a base station considering the selected SS/PBCH index, and the base station receiving the PRACH can obtain information on the SS/PBCH block index selected by the terminal. The base station can know which block the terminal has selected from each SS/PBCH block and monitor the control region #0 corresponding to (or associated with) the SS/PBCH block selected by the terminal.

Below, downlink control information (DCI) in the NR system is specifically described.

In an NR system, scheduling information for uplink data (or physical uplink shared channel, PUSCH) or downlink data (or physical downlink shared channel, PDSCH) can be transmitted from a base station to a terminal via DCI. The terminal can monitor a DCI format for fallback and a DCI format for non-fallback for the PUSCH or PDSCH. The fallback DCI format can be composed of fixed fields predefined between the base station and the terminal, and the non-fallback DCI format can include configurable fields.

DCI can be transmitted through PDCCH, which is a physical downlink control channel, after going through channel coding and modulation processes. A cyclic redundancy check (CRC) can be attached to the DCI message payload, and the CRC can be scrambled with an RNTI (radio network temporary identifier) corresponding to the identity of the UE. Depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response, different RNTIs can be used for scrambling the CRC attached to the payload of the DCI message. That is, the RNTI can be transmitted by being included in the CRC calculation process without being explicitly transmitted. When a DCI message transmitted on the PDCCH is received, the UE can check the CRC using the allocated RNTI. If the CRC check result is correct, the UE can know that the corresponding message was transmitted to the UE.

For example, a DCI scheduling a PDSCH for system information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a random access response (RAR) message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a paging message may be scrambled with P-RNTI. A DCI notifying a slot format indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a transmit power control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (cell RNTI).

DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. In one embodiment, DCI format 0_0 with CRC scrambled with C-RNTI can include information as shown in Table 3 below.

] bits
- Time domain resource assignment (시간 도메인 자원 할당) - X bits
- Frequency hopping flag (주파수 호핑 플래그) - 1 bit.
- Modulation and coding scheme (변조 및 코딩 스킴) - 5 bits
- New data indicator (새로운 데이터 지시자) - 1 bit
- Redundancy version (리던던시 버전) - 2 bits
- HARQ process number (HARQ 프로세스 번호) - 4 bits
- TPC command for scheduled PUSCH (스케줄링된 PUSCH를 위한 전송 전력 제어(transmit power control) 명령 - [2] bits
- UL/SUL indicator (상향링크/추가적 상향링크(supplementary UL) 지시자) - 0 or 1 bit
- Identifier for DCI formats (DCI format identifier) - [1] bit
- Frequency domain resource assignment -[

] bits
- Time domain resource assignment (Time domain resource assignment) - X bits
- Frequency hopping flag - 1 bit.
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
- HARQ process number (HARQ process number) - 4 bits
- TPC command for scheduled PUSCH (Transmit power control command for scheduled PUSCH - [2] bits
- UL/SUL indicator (uplink/supplementary uplink (supplementary UL) indicator) - 0 or 1 bit

DCI format 0_1 can be used as a non-fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. In one embodiment, DCI format 0_1 with CRC scrambled with C-RNTI can include information as shown in Table 4 below.

bits
- For resource allocation type 1(자원 할당 타입 1의 경우),

bits
- Time domain resource assignment -1, 2, 3, or 4 bits
- VRB-to-PRB mapping (가상 자원 블록(virtual resource block)-to-물리 자원 블록(physical resource block) 매핑) - 0 or 1 bit, only for resource allocation type 1.
○ 0 bit if only resource allocation type 0 is configured;
○ 1 bit otherwise.
- Frequency hopping flag - 0 or 1 bit, only for resource allocation type 1.
○ 0 bit if only resource allocation type 0 is configured;
○ 1 bit otherwise.
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
- HARQ process number - 4 bits
- 1st downlink assignment index (제1 하향링크 할당 인덱스)- 1 or 2 bits
○ 1 bit for semi-static HARQ-ACK codebook(준정적 HARQ-ACK 코드북의 경우);
○ 2 bits for dynamic HARQ-ACK codebook with single HARQ-ACK codebook(단일 HARQ-ACK 코드북과 함께 동적 HARQ-ACK 코드북이 사용되는 경우).
- 2nd downlink assignment index (제2 하향링크 할당 인덱스) - 0 or 2 bits
○ 2 bits for dynamic HARQ-ACK codebook with two HARQ-ACK sub-codebooks(2개의 HARQ-ACK 부코드북과 함께 동적 HARQ-ACK 코드북이 사용되는 경우);
○ 0 bit otherwise.
TPC command for scheduled PUSCH - 2 bits
- SRS resource indicator (SRS 자원 지시자) -

or

bits
○

bits for non-codebook based PUSCH transmission(PUSCH 전송이 코드북 기반이 아닐 경우);
○

bits for codebook based PUSCH transmission(PUSCH 전송이 코드북 기반일 경우).
- Precoding information and number of layers (프리코딩 정보 및 레이어의 개수)-up to 6 bits
- Antenna ports (안테나 포트)- up to 5 bits
- SRS request (SRS 요청)- 2 bits
- CSI request (채널 상태 정보 요청) - 0, 1, 2, 3, 4, 5, or 6 bits
- CBG transmission information (코드 블록 그룹(code block group) 전송 정보)- 0, 2, 4, 6, or 8 bits
- PTRS-DMRS association (위상 트래킹 기준 신호-복조 기준 신호 관계)- 0 or 2 bits.
- beta_offset indicator (베타 오프셋 지시자)- 0 or 2 bits
- DMRS sequence initialization (복조 기준 신호 시퀀스 초기화)- 0 or 1 bit- Carrier indicator - 0 or 3 bits
- UL/SUL indicator - 0 or 1 bit
- Identifier for DCI formats - [1] bits
- Bandwidth part indicator - 0, 1 or 2 bits
- Frequency domain resource assignment
- For resource allocation type 0 (For resource allocation type 0),

bits
- For resource allocation type 1 (For resource allocation type 1),

bits
- Time domain resource assignment -1, 2, 3, or 4 bits
- VRB-to-PRB mapping (virtual resource block-to-physical resource block mapping) - 0 or 1 bit, only for resource allocation type 1.
○ 0 bit if only resource allocation type 0 is configured;
○ 1 bit otherwise.
- Frequency hopping flag - 0 or 1 bit, only for resource allocation type 1.
○ 0 bit if only resource allocation type 0 is configured;
○ 1 bit otherwise.
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
- HARQ process number - 4 bits
- 1st downlink assignment index (1st downlink assignment index) - 1 or 2 bits
○ 1 bit for semi-static HARQ-ACK codebook;
○ 2 bits for dynamic HARQ-ACK codebook with single HARQ-ACK codebook (When dynamic HARQ-ACK codebook is used with single HARQ-ACK codebook).
- 2nd downlink assignment index - 0 or 2 bits
○ 2 bits for dynamic HARQ-ACK codebook with two HARQ-ACK sub-codebooks (When dynamic HARQ-ACK codebook is used with two HARQ-ACK sub-codebooks);
○ 0 bit otherwise.
TPC command for scheduled PUSCH - 2 bits
- SRS resource indicator (SRS resource indicator) -

or

bits
○

bits for non-codebook based PUSCH transmission;
○

bits for codebook based PUSCH transmission(If PUSCH transmission is codebook based).
- Precoding information and number of layers (Precoding information and number of layers) - up to 6 bits
- Antenna ports (Antenna ports) - up to 5 bits
- SRS request- 2 bits
- CSI request (Channel State Information Request) - 0, 1, 2, 3, 4, 5, or 6 bits
- CBG transmission information (code block group transmission information) - 0, 2, 4, 6, or 8 bits
- PTRS-DMRS association (Phase Tracking Reference Signal-Demodulation Reference Signal Association)- 0 or 2 bits.
- beta_offset indicator (Beta offset indicator) - 0 or 2 bits
- DMRS sequence initialization (Demodulation reference signal sequence initialization) - 0 or 1 bit

DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. In one embodiment, DCI format 1_0 with CRC scrambled with C-RNTI can include information as shown in Table 5 below.

] bits
- Time domain resource assignment - X bits
- VRB-to-PRB mapping - 1 bit.
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
- HARQ process number - 4 bits
- Downlink assignment index - 2 bits
- TPC command for scheduled PUCCH - [2] bits
- PUCCH resource indicator (물리 상향링크 제어 채널(physical uplink control channel, PUCCH) 자원 지시자- 3 bits
- PDSCH-to-HARQ feedback timing indicator (PDSCH-to-HARQ 피드백 타이밍 지시자)- [3] bits- Identifier for DCI formats - [1] bit
- Frequency domain resource assignment -[

] bits
- Time domain resource assignment - X bits
- VRB-to-PRB mapping - 1 bit.
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
- HARQ process number - 4 bits
- Downlink assignment index - 2 bits
- TPC command for scheduled PUCCH - [2] bits
- PUCCH resource indicator (physical uplink control channel, PUCCH) resource indicator - 3 bits
- PDSCH-to-HARQ feedback timing indicator (PDSCH-to-HARQ feedback timing indicator) - [3] bits

Alternatively, DCI format 1_0 can be used as a DCI for scheduling PDSCH for a RAR message, in which case the CRC can be scrambled with RA-RNTI. DCI format 1_0 with CRC scrambled with RA-RNTI can include information as shown in Table 6 below.

bits
- Time domain resource assignment - 4 bits
- VRB-to-PRB mapping - 1 bit
- Modulation and coding scheme - 5 bits
- TB scaling - 2 bits
- Reserved bits - 16 bits- Frequency domain resource assignment -

bits
- Time domain resource assignment - 4 bits
- VRB-to-PRB mapping - 1 bit
- Modulation and coding scheme - 5 bits
- TB scaling - 2 bits
- Reserved bits - 16 bits

DCI format 1_1 can be used as a non-fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. In one embodiment, the DCI format 1_1 with the CRC scrambled with C-RNTI can include information as shown in Table 7 below.

bits
○ For resource allocation type 1,

bits
- Time domain resource assignment -1, 2, 3, or 4 bits
- VRB-to-PRB mapping - 0 or 1 bit, only for resource allocation type 1.
○ 0 bit if only resource allocation type 0 is configured;
○ 1 bit otherwise.
- PRB bundling size indicator (물리 자원 블록 번들링 크기 지시자) - 0 or 1 bit
- Rate matching indicator (레이트 매칭 지시자) - 0, 1, or 2 bits
- ZP CSI-RS trigger (영전력 채널 상태 정보 기준 신호 트리거) - 0, 1, or 2 bits
For transport block 1(제1 전송 블록의 경우):
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
For transport block 2(제2 전송 블록의 경우):
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
- HARQ process number - 4 bits
- Downlink assignment index - 0 or 2 or 4 bits
- TPC command for scheduled PUCCH - 2 bits
- PUCCH resource indicator - 3 bits
- PDSCH-to-HARQ_feedback timing indicator - 3 bits
- Antenna ports - 4, 5 or 6 bits
- Transmission configuration indication (전송 설정 지시)- 0 or 3 bits
- SRS request - 2 bits
- CBG transmission information - 0, 2, 4, 6, or 8 bits
- CBG flushing out information (코드 블록 그룹 플러싱 아웃 정보) - 0 or 1 bit
- DMRS sequence initialization - 1 bit- Carrier indicator - 0 or 3 bits
- Identifier for DCI formats - [1] bits
- Bandwidth part indicator - 0, 1 or 2 bits
- Frequency domain resource assignment
○ For resource allocation type 0,

bits
○ For resource allocation type 1,

bits
- Time domain resource assignment -1, 2, 3, or 4 bits
- VRB-to-PRB mapping - 0 or 1 bit, only for resource allocation type 1.
○ 0 bit if only resource allocation type 0 is configured;
○ 1 bit otherwise.
- PRB bundling size indicator (Physical Resource Block Bundling Size Indicator) - 0 or 1 bit
- Rate matching indicator - 0, 1, or 2 bits
- ZP CSI-RS trigger (Zero Power Channel State Information Reference Signal Trigger) - 0, 1, or 2 bits
For transport block 1 (For the first transport block):
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
For transport block 2:
- Modulation and coding scheme - 5 bits
- New data indicator - 1 bit
- Redundancy version - 2 bits
- HARQ process number - 4 bits
- Downlink assignment index - 0 or 2 or 4 bits
- TPC command for scheduled PUCCH - 2 bits
- PUCCH resource indicator - 3 bits
- PDSCH-to-HARQ_feedback timing indicator - 3 bits
- Antenna ports - 4, 5 or 6 bits
- Transmission configuration indication - 0 or 3 bits
- SRS request - 2 bits
- CBG transmission information - 0, 2, 4, 6, or 8 bits
- CBG flushing out information (Code Block Group Flushing Out Information) - 0 or 1 bit
- DMRS sequence initialization - 1 bit

FIG. 4 is a diagram illustrating an example of the structure of a downlink control channel of a wireless communication system. In particular, FIG. 4 illustrates an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in a 5G system.

Referring to Fig. 4, the basic unit of time and frequency resources constituting a control channel can be defined as a REG (resource element group, 4-03). A REG (4-03) can be defined as 1 OFDM symbol (4-01) in the time axis and 1 PRB (physical resource block, 4-02) in the frequency axis, i.e., 12 subcarriers. A base station can concatenate REGs (4-03) to configure a downlink control channel allocation unit.

As illustrated in FIG. 4, if the basic unit to which a downlink control channel is allocated in a 5G system is called a CCE (control channel element, 4-04), 1 CCE (4-04) can be composed of multiple REGs (4-03). For example, the REG (4-03) illustrated in FIG. 4 can be composed of 12 REs, and if 1 CCE (4-04) is composed of 6 REGs (4-03), 1 CCE (4-04) can be composed of 72 REs. When a downlink control region is set, the region can be composed of multiple CCEs (4-04), and a specific downlink control channel can be mapped to one or multiple CCEs (4-04) and transmitted according to the aggregation level (AL) within the control region. CCEs (4-04) within the control area are distinguished by numbers, and the numbers of the CCEs (4-04) can be assigned according to a logical mapping method.

The basic unit of the downlink control channel illustrated in Fig. 4, that is, REG (4-03), may include both REs to which DCI is mapped and areas to which DMRS (4-05), which is a reference signal for decoding the REs, is mapped. As in Fig. 4, three DMRSs (4-05) may be transmitted in one REG (4-03). The number of CCEs required to transmit a PDCCH may be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs may be used to implement link adaptation of the downlink control channel. For example, when AL = L, one downlink control channel may be transmitted through L CCEs.

A terminal must detect a signal without knowing information about a downlink control channel. A search space representing a set of CCEs for blind decoding can be defined. A search space is a set of downlink control channel candidates consisting of CCEs that the terminal should attempt to decode at a given aggregation level. Since there are various aggregation levels that form a single bundle with 1, 2, 4, 8, and 16 CCEs, a terminal can have multiple search spaces. A search space set can be defined as a set of search spaces at all configured aggregation levels.

The search space can be classified into a common search space and a UE-specific search space. According to one embodiment of the present disclosure, a certain group of terminals or all terminals can search the common search space of the PDCCH to receive cell-common control information such as dynamic scheduling or paging messages for system information.

For example, the terminal can receive PDSCH scheduling allocation information for transmission of SIB including operator information of the cell, etc., by examining the common search space of the PDCCH. In the case of the common search space, since a certain group of terminals or all terminals must receive the PDCCH, the common search space can be defined as a set of pre-promised CCEs. Meanwhile, the terminal can receive scheduling allocation information for a terminal-specific PDSCH or PUSCH by examining the terminal-specific search space of the PDCCH. The terminal-specific search space can be defined terminal-specifically as a function of the identity of the terminal and various system parameters.

In a 5G system, parameters for a search space for PDCCH can be set from a base station to a terminal through higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can set, to the terminal, the number of PDCCH candidates in each aggregation level L, a monitoring period for the search space, a monitoring occasion for each symbol in a slot for the search space, a search space type (common search space or terminal-specific search space), a combination of DCI formats and RNTIs to be monitored in the corresponding search space, a control region index to be monitored for the search space, etc. For example, the above-described configuration can include information such as Table 8 below.

SearchSpace ::= SEQUENCE {
-- Identity of the search space. SearchSpaceId = 0 identifies the SearchSpace configured via PBCH (MIB) or ServingCellConfigCommon.
searchSpaceId SearchSpaceId,
(search space identifier)
controlResourceSetId ControlResourceSetId,
(control area identifier)
monitoringSlotPeriodicityAndOffset CHOICE {
(Monitoring slot level cycle)
sl1 NULL,
sl2 INTEGER (0..1),
sl4 INTEGER (0..3),
sl5 INTEGER (0..4),
sl8 INTEGER (0..7),
sl10 INTEGER (0..9),
sl16 INTEGER (0..15),
sl20 INTEGER (0..19)
} OPTIONAL,
duration(monitoring length) INTEGER (2..2559)
monitoringSymbolsWithinSlot BIT STRING (SIZE (14)) OPTIONAL,
(Monitoring symbol in slot)
nrofCandidates SEQUENCE {
(Number of PDCCH candidates by aggregation level)
aggregationLevel1 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},
aggregationLevel2 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},
aggregationLevel4 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},
aggregationLevel8 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},
aggregationLevel16 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}
},

searchSpaceType CHOICE {
(search space type)
-- Configures this search space as common search space (CSS) and DCI formats to monitor.
common SEQUENCE {
(common search space)
}
ue-Specific SEQUENCE {
(Terminal-specific search space)
-- Indicates whether the UE monitors in this USS for DCI formats 0-0 and 1-0 or for formats 0-1 and 1-1.
formats ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1},
...
}

Based on the configuration information, the base station can configure one or more search space sets for the terminal. According to one embodiment of the present disclosure, the base station can configure search space set 1 and search space set 2 for the terminal, and configure the terminal to monitor DCI format A scrambled with X-RNTI in search space set 1 in a common search space, and configure the terminal to monitor DCI format B scrambled with Y-RNTI in search space set 2 in a terminal-specific search space.

According to the configuration information, one or more search space sets may exist in the common search space or the terminal-specific search space. For example, search space set #1 and search space set #2 may be set as the common search space, and search space set #3 and search space set #4 may be set as the terminal-specific search space.

The common search space can be classified into a search space set of a specific type according to the purpose. The RNTI to be monitored can be different for each type of search space set. For example, the common search space type, purpose, and RNTI to be monitored can be classified as shown in Table 9 below.

Exploration space type purpose RNTI Type0 CSS PDCCH transmission for SIB scheduling SI-RNTI Type0A CSS PDCCH transmission for SI scheduling other than SIB1 (such as SIB2) SI-RNTI Type1 CSS PDCCH transmission for RAR scheduling, Msg3 retransmission scheduling, and Msg4 scheduling RA-RNTI, TC-RNTI Type2 CSS Paging P-RNTI Type3 CSS Send group control information INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI PDCCH transmission for data scheduling in case of PCell C-RNTI, MCS-C-RNTI, CS-RNTI

Meanwhile, in the common search space, the combination of the DCI format and RNTI below can be monitored. Of course, it is not limited to the examples below.

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

- DCI format 2_0 with CRC scrambled by SFI-RNTI

- DCI format 2_1 with CRC scrambled by INT-RNTI

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

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

In a terminal-specific search space, the following combinations of DCI formats and RNTIs can be monitored, although they are not limited to the examples below.

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

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

The RNTIs specified may follow the definitions and uses below.

- C-RNTI (Cell RNTI): For terminal-specific PDSCH scheduling purposes.

- TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes.

- CS-RNTI (Configured Scheduling RNTI): For terminal-specific PDSCH scheduling that is set semi-statically.

- RA-RNTI (Random Access RNTI): For PDSCH scheduling in the random access phase.

- P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

- SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

- INT-RNTI (Interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

- TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control command for PUSCH.

- TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control command for PUCCH (physical uplink control channel).

- TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

In one embodiment, the DCI formats described above may be defined as shown in Table 10 below.

DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1 Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1 Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slot format 2_1 Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE 2_2 Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of a group of TPC commands for SRS transmissions by one or more UEs

According to one embodiment of the present disclosure, in a 5G system, a plurality of search space sets may be set with different parameters (e.g., parameters of Table 8). Accordingly, a set of search space sets monitored by a terminal at each point in time may be different. For example, if search space set #1 is set to an X-slot period and search space set #2 is set to a Y-slot period and X and Y are different, the terminal may monitor both search space set #1 and search space set #2 in a specific slot, and may monitor one of search space set #1 and search space set #2 in a specific slot.

Below, methods for allocating time and frequency resources for data transmission in NR systems are described.

In addition to frequency domain resource candidate allocation through BWP indication, the NR system may provide the following detailed frequency domain resource allocation methods (frequency domain resource allocation, FD-RA).

FIG. 5 is a diagram illustrating an example of frequency-axis resource allocation of PDSCH in a wireless communication system.

Figure 5 is a diagram illustrating three frequency axis resource allocation methods that can be set via upper layers in an NR system: type 0 (5-00), type 1 (5-05), and dynamic switch (5-10).

Referring to Fig. 5, if a terminal is set to use only resource type 0 through upper layer signaling (5-00), some downlink control information (DCI) that allocates PDSCH to the terminal has a bitmap consisting of N _RBG bits. The conditions for this will be explained later. At this time, N _RBG means the number of RBGs (resource block groups) determined according to the BWP size allocated by the BWP indicator and the upper layer parameter rbg-Size as shown in Table 11 below, and data is transmitted to the RBG indicated as 1 by the bitmap.

Bandwidth Part Size Configuration 1 Configuration 2 1-36 2 4 37-72 4 8 73-144 8 16 145-275 16 16

개의 비트들로 구성되는 주파수 축 자원 할당 정보를 가진다. 이를 위한 조건은 차후 다시 설명된다. 기지국은 이를 통하여 starting VRB(6-20)와 이로부터 연속적으로 할당되는 주파수 축 자원의 길이(6-25)를 설정할 수 있다.If the terminal is set to use only resource type 1 through upper layer signaling (6-05), some DCIs that allocate PDSCH to the terminal

It has frequency axis resource allocation information consisting of bits. The conditions for this will be explained later. Through this, the base station can set the starting VRB (6-20) and the length of frequency axis resources (6-25) allocated continuously therefrom.

If a terminal is configured to use both resource type 0 and resource type 1 through upper layer signaling (5-10), some DCIs that allocate PDSCH to the terminal have frequency-axis resource allocation information consisting of bits of the larger value (5-35) among the payload (5-15) for configuring resource type 0 and the payload (5-20, 5-25) for configuring resource type 1. The conditions for this will be explained later. At this time, one bit can be added to the most significant bit (MSB) of the frequency-axis resource allocation information in the DCI, and if the bit is 0, it can indicate that resource type 0 is used, and if it is 1, it can indicate that resource type 1 is used.

Below, the time domain resource allocation method for data channels in NR systems is described.

The base station can set up a table for time domain resource allocation information for the downlink data channel (PDSCH) and the uplink data channel (PUSCH) to the terminal through higher layer signaling (e.g., RRC signaling). For the PDSCH, a table consisting of up to maxNrofDL-Allocations=16 entries can be set up, and for the PUSCH, a table consisting of up to maxNrofUL-Allocations=16 entries can be set up. In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to a time interval in slot units between a time point when a PDCCH is received and a time point when a PDSCH scheduled by the received PDCCH is transmitted, denoted as K0), PDCCH-to-PUSCH slot timing (corresponding to a time interval in slot units between a time point when a PDCCH is received and a PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information about a position and a length of a start symbol in which a PDSCH or PUSCH is scheduled within a slot, a mapping type of the PDSCH or PUSCH, etc. For example, information such as Table 12 or Table 13 below may be notified from a base station to a terminal.

PDSCH-TimeDomainResourceAllocationList information element
PDSCH-TimeDomainResourceAllocationList ::= SEQUENCE (SIZE(1..maxNrofDL-Allocations)) OF PDSCH-TimeDomainResourceAllocation

PDSCH-TimeDomainResourceAllocation ::= SEQUENCE {
k0 INTEGER(0..32) OPTIONAL, -- Need S
(PDCCH-to-PDSCH timing, slot unit)
mappingType ENUMERATED {typeA, typeB},
(PDSCH mapping type)
startSymbolAndLength INTEGER (0..127)
(Start symbol and length of PDSCH)
}

PUSCH-TimeDomainResourceAllocation information element
PUSCH-TimeDomainResourceAllocationList ::= SEQUENCE (SIZE(1..maxNrofUL-Allocations)) OF PUSCH-TimeDomainResourceAllocation

PUSCH-TimeDomainResourceAllocation ::= SEQUENCE {
k2 INTEGER(0..32) OPTIONAL, -- Need S
(PDCCH-to-PUSCH timing, slot unit)
mappingType ENUMERATED {typeA, typeB},
(PUSCH mapping type)
startSymbolAndLength INTEGER (0..127)
(PUSCH start symbol and length)
}

The base station may notify the terminal of one of the entries in the table for the time domain resource allocation information described above via L1 signaling (e.g., DCI) (e.g., it may be indicated by the 'time domain resource allocation' field in the DCI). The terminal may obtain the time domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

FIG. 6 is a diagram illustrating an example of time domain resource allocation of PDSCH in a wireless communication system.

Referring to FIG. 6, the base station can indicate the time axis position of the PDSCH resource according to the subcarrier spacing (SCS, μ _PDSCH , μ _PDCCH ) of the data channel and control channel set by using the upper layer, the slot offset (K ₀ ) value, and the start position (6-00) and length (6-05) of the OFDM symbol within a slot dynamically indicated through DCI.

FIG. 7 is a diagram illustrating an example of time-domain resource allocation according to the subcarrier spacing of a data channel and a control channel in a wireless communication system.

Referring to Fig. 7, when the subcarrier spacing of the data channel and the control channel are the same (7-00, μ _PDSCH = μ _PDCCH ), the slot number for data and control is the same, so the base station and the terminal can know that the scheduling offset occurs according to the predetermined slot offset K ₀ . On the other hand, when the subcarrier spacing of the data channel and the control channel are different (7-05, μ _PDSCH ≠ μ _PDCCH ), since the slot numbers for data and control are different, the base station and the terminal can know that the scheduling offset occurs according to the predetermined slot offset K ₀ based on the subcarrier spacing of the PDCCH.

Below, we describe the quasi co-location (QCL) and transmission configuration indication (TCI) states.

In a wireless communication system, one or more different antenna ports (or one or more channels, signals, and combinations thereof may be replaced, but for convenience in the description of the present disclosure, they will be referred to as different antenna ports together) may be associated with each other by a QCL (quasi co-location) setting as shown in Table 14 below. The TCI state is to notify the QCL relationship between the PDCCH (or PDCCH DMRS) and other RSs or channels. When a certain reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) are QCLed with each other, it means that the terminal is allowed to apply some or all of the large-scale channel parameters estimated at the antenna port A to the channel measurement from the antenna port B. QCL may need to relate different parameters depending on the situation, such as 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) radio resource management (RRM) affected by average gain, and 4) beam management (BM) affected by spatial parameters. Accordingly, NR supports four types of QCL relationships, as shown in Table 14 below.

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 Rx parameter

The above spatial RX parameter may collectively refer to some or all of various parameters, such as Angle of arrival (AoA), Power Angular Spectrum (PAS) of AoA, Angle of departure (AoD), PAS of AoD, transmit/receive channel correlation, transmit/receive beamforming, and spatial channel correlation.

The above QCL relationship can be set to the terminal through the RRC parameters TCI-State and QCL-Info as shown in Table 15 below. Referring to Table 15, the base station can set one or more TCI states to the terminal and inform the RS referring to the ID of the TCI state, i.e., up to two QCL relationships (qcl-Type1, qcl-Type2) for the target RS. At this time, each QCL information (QCL-Info) included in the above TCI state includes the serving cell index and BWP index of the reference RS indicated by the corresponding QCL information, the type and ID of the reference RS, and the QCL type as shown in Table 15 above.

TCI-State ::= SEQUENCE {
tci-StateId TCI-StateId,
(ID of the corresponding TCI state)
qcl-Type1 QCL-Info,
(QCL information of the first reference RS of the RS (target RS) referencing the corresponding TCI state ID)
qcl-Type2 QCL-Info OPTIONAL, -- Need R
(QCL information of the second reference RS of the RS (target RS) referencing the corresponding TCI state ID)
...
}

QCL-Info ::= SEQUENCE {
cell ServCellIndex OPTIONAL, -- Need R
(serving cell index of the reference RS pointed to by the corresponding QCL information)
bwp-Id BWP-Id OPTIONAL, -- Cond CSI-RS-Indicated
(BWP index of the reference RS pointed to by the corresponding QCL information)
referenceSignal CHOICE {
csi-rs NZP-CSI-RS-ResourceId,
ssb SSB-Index
(either the CSI-RS (channel state information reference signal) ID or SSB ID pointed to by the corresponding QCL information)
},
qcl-Type ENUMERATED {typeA, typeB, typeC, typeD},
...
}

Below, we describe in detail the QCL priority determination operation for PDCCH.

When a terminal operates in a single cell or with carrier aggregation (CA) within a band, and multiple control regions existing in an activated bandwidth portion of a single or multiple cells have the same or different QCL-TypeD characteristics and overlap in time during a specific PDCCH monitoring interval, the terminal may select a specific control region according to a QCL priority determination operation, and monitor control regions having the same QCL-TypeD characteristic as the selected control region. That is, when multiple control regions overlap in time, only one QCL-TypeD characteristic can be received. In this case, the criteria for determining the QCL priority may be as follows.

- Criteria 1. A control area connected to the common search section of the lowest index within the cell corresponding to the lowest index among the cells containing the common search space (CSS).

- Criteria 2. A control area connected to the terminal-specific search section of the lowest index within the cell corresponding to the lowest index among the cells containing the terminal-specific search space (USS).

As described above, if each of the above criteria is not satisfied, the next criterion is applied. For example, if the control regions overlap in time in a specific PDCCH monitoring interval, and if all the control regions are not connected to a common search interval but to a terminal-specific search interval, i.e., if criterion 1 is not satisfied, the terminal may omit the application of criterion 1 and apply criterion 2.

When the terminal selects a control region by the above-described criteria, the terminal may additionally consider the following two items with respect to the QCL information set in the control region. First, if control region 1 has CSI-RS 1 as a reference signal having a QCL-TypeD relationship, and the reference signal of this CSI-RS 1 having a QCL-TypeD relationship is SSB 1, and another control region 2 has a reference signal having a QCL-TypeD relationship also as SSB 1, the terminal may consider that these two control regions 1 and 2 have different QCL-TypeD characteristics. Second, if control region 1 has CSI-RS 1 set in cell 1 as a reference signal having QCL-TypeD relationship, and the reference signal of this CSI-RS 1 having QCL-TypeD relationship is SSB 1, and control region 2 has CSI-RS 2 set in cell 2 as a reference signal having QCL-TypeD relationship, and the reference signal of this CSI-RS 2 having QCL-TypeD relationship is the same SSB 1, the terminal can consider that the two control regions have the same QCL-TypeD characteristic.

Below, we describe the HARQ-ACK (hybrid automatic repeat request - acknowledgement) feedback transmission method.

The NR system adopts the HARQ scheme, which retransmits the data in the physical layer when a decoding failure occurs in the initial transmission. The HARQ scheme means that when the receiver fails to correctly decode data, the receiver transmits information (negative acknowledgement, NACK) notifying the transmitter of the decoding failure so that the transmitter can retransmit the data in the physical layer. The receiver combines the data retransmitted by the transmitter with the data that previously failed to be decoded to improve data reception performance. In addition, when the receiver correctly decodes the data, the receiver can transmit information (acknowledgement, ACK) notifying the transmitter of the decoding success so that the transmitter can transmit new data.

The present disclosure below describes a method and device for transmitting HARQ-ACK feedback for downlink data transmission. Specifically, a method for configuring HARQ-ACK feedback bits when a terminal wishes to transmit multiple HARQ-ACKs within one slot in uplink is described.

In the NR system, a base station can set one component carrier (CC) or multiple CCs for downlink transmission to a terminal. In addition, downlink transmission and uplink transmission slots and symbols can be set in each CC. Meanwhile, when downlink data, PDSCH, is scheduled, at least one of slot timing information to which PDSCH is mapped, information on a start symbol position to which PDSCH is mapped within the slot, and information on the number of symbols to which PDSCH is mapped can be transmitted in a specific bit field of DCI. For example, when DCI is transmitted in slot n and PDSCH is scheduled, if K0, which is slot timing information to which PDSCH is transmitted, indicates 0, the start symbol position is 0, and the symbol length is 7, the corresponding PDSCH is mapped to and transmitted from symbol 0 of slot n to 7 symbols. Meanwhile, when PDSCH, which is a downlink data signal, is transmitted, HARQ-ACK feedback is transmitted from the terminal to the base station after slot K1. K1 information, which is the timing information for transmitting HARQ-ACK, is transmitted in the DCI, and a set of candidate K1 values that are possible are transmitted through upper signaling, and one of them can be determined in the DCI.

When a semi-static HARQ-ACK codebook is set for a terminal, the terminal can determine feedback bits to be transmitted (or HARQ-ACK codebook size) based on candidate values of K1, which is HARQ-ACK feedback timing information for PDSCH, and a table including K0, which is slot information to which PDSCH is mapped, start symbol information, number of symbols or length information. The table including slot information to which PDSCH is mapped, start symbol information, number of symbols or length information can follow a default value, or can also be set by the base station to the terminal.

When a terminal is configured with a dynamic HARQ-ACK codebook, the terminal can determine the HARQ-ACK feedback bits (or HARQ-ACK codebook size) to be transmitted by the terminal based on the DAI (downlink assignment indicator) information included in the DCI in the slot in which HARQ-ACK information is transmitted based on the K0 value, which is slot information to which the PDSCH is mapped, and the K1 value, which is HARQ-ACK feedback timing information for the PDSCH.

Figure 8 is a diagram illustrating an example of a method for setting a semi-static HARQ-ACK codebook in an NR system.

In a situation where the number of HARQ-ACK PUCCHs that a UE can transmit in a slot is limited to one, when the UE receives a higher layer signal that sets a semi-static HARQ-ACK codebook, the UE can report HARQ-ACK information for PDSCH reception or SPS PDSCH release in the HARQ-ACK codebook in a slot indicated by the value of the PDSCH-to-HARQ_feedback timing indicator field included in DCI format 1_0 or DCI format 1_1. The UE can report HARQ-ACK information bit values as NACK in the HARQ-ACK codebook in a slot that is not indicated by the PDSCH-to-HARQ_feedback timing indicator field in DCI format 1_0 or DCI format 1_1. If a UE reports only one SPS PDSCH release or HARQ-ACK information for one PDSCH reception in the M _A,c cases for candidate PDSCH reception, and the report is scheduled by DCI format 1_0 including information that the counter DAI field in the Pcell is indicated as 1, the UE can determine one HARQ-ACK codebook for the corresponding SPS PDSCH release or the corresponding PDSCH reception.

Other than that, the HARQ-ACK codebook determination method can be followed according to the following method.

If the set of PDSCH reception candidate cases in serving cell c is called M _A,c, M _A,c can be obtained through the following pseudo-code 1 steps.

[pseudo-code 1 start]

- Step 1: Initialize j to 0 and M _A,c to the empty set. Initialize k, the HARQ-ACK transmission timing index, to 0.

- Step 2: Set R as a set of rows in a table including slot information, start symbol information, number of symbols, or length information to which PDSCH is mapped. If the PDSCH-capable mapping symbol indicated by each value of R is set to a UL symbol according to the DL and UL settings set from above, delete the corresponding row from R.

- Step 3-1: If the terminal can receive one unicast PDSCH in one slot and R is not an empty set, add one to the set M _A,c .

- Step 3-2: If the terminal can receive more than one PDSCH for unicast in one slot, count the number of PDSCHs that can be allocated to different symbols in the calculated R and add that number to M _A,c .

- Step 4: Increase k by 1 and start again from step 2.

[end of pseudo-code 1]

Referring to Fig. 8, explaining the pseudo-code 1 described above, in order to perform HARQ-ACK PUCCH transmission in slot#k(8-08), the UE can consider all slot candidates that have PDSCH-to-HARQ-ACK timing that can indicate slot#k(8-08). In Fig. 8, it is assumed that HARQ-ACK transmission is possible in slot#k(8-08) by PDSCH-to-HARQ-ACK timing combinations that are possible only for PDSCHs scheduled in slot#n(8-02), slot#n+1(8-04), and slot#n+2(8-06). In addition, the maximum number of schedulable PDSCHs for each slot can be derived by considering time domain resource configuration information of PDSCHs that can be scheduled in slots 8-02, 8-04, and 8-06, respectively, and information indicating whether a symbol in the slot is a downlink or an uplink. For example, if two PDSCHs can be scheduled at maximum in slot 8-02, three PDSCHs can be scheduled at slot 8-04, and two PDSCHs can be scheduled at maximum in slot 8-06, the maximum number of PDSCHs included in the HARQ-ACK codebook transmitted in slot 8-08 is 7. This is called the cardinality of the HARQ-ACK codebook.

Figure 9 is a diagram illustrating an example of a method for setting a dynamic HARQ-ACK codebook in an NR system.

The terminal can transmit HARQ-ACK information transmitted within a PUCCH in slot n based on the PDSCH-to-HARQ_feedback timing value for PUCCH transmission of HARQ-ACK information for PDSCH reception or SPS PDSCH release and K0, which is the transmission slot location information of the PDSCH scheduled in DCI format 1_0 or 1_1.

Specifically, for the HARQ-ACK information transmission described above, the terminal can determine the PDSCH-to-HARQ_feedback timing based on the DAI included in the DCI indicating the PDSCH or SPS PDSCH release and the HARQ-ACK codebook of the PUCCH transmitted in the slot determined by K0.

The above DAI is composed of a counter DAI and a total DAI. The counter DAI is information that indicates the position of HARQ-ACK information corresponding to a PDSCH scheduled in DCI format 1_0 or DCI format 1_1 in a HARQ-ACK codebook. Specifically, the value of the counter DAI in DCI format 1_0 or 1_1 indicates the accumulated value of PDSCH reception or SPS PDSCH release scheduled by DCI format 1_0 or DCI format 1_1 in a specific cell c. The above-described accumulated value is set based on the PDCCH monitoring occasion and serving cell in which the scheduled DCI exists.

Total DAI is a value indicating the HARQ-ACK codebook size. Specifically, the value of total DAI means the total number of previously scheduled PDSCH or SPS PDSCH releases including the time when DCI is scheduled (PDCCH monitoring occasion). In addition, total DAI is a parameter used in a CA situation when HARQ-ACK information in serving cell c also includes HARQ-ACK information for PDSCHs scheduled in other cells including serving cell c. In other words, the total DAI parameter does not exist in a system operating with one cell.

FIG. 9 is a diagram illustrating an example of operation of a terminal related to the DAI when a dynamic HARQ-ACK codebook is used. In FIG. 9, when a terminal is configured with two carriers (c), when transmitting a HARQ-ACK codebook selected based on DAI on the nth slot of carrier 0 (9-02) on PUCCH (9-20), changes in the values of the counter DAI (C-DAI) and the total DAI (T-DAI) indicated by the DCI searched for each PDCCH monitoring occasion set for each carrier are illustrated. First, in the DCI searched for m = 0 (9-06), C-DAI and T-DAI each indicate a value of 1 (9-12). In the DCI searched for m = 1 (9-08), C-DAI and T-DAI each indicate a value of 2 (9-14). In the DCI searched on carrier 0 (c=0, 9-02) of m=2(9-10), C-DAI indicates the value of 3 (9-16). In the DCI searched on carrier 1 (c=1, 9-04) of m=2(9-10), C-DAI indicates the value of 4 (9-18). In this case, if carriers 0 and 1 are scheduled in the same monitoring occasion, both T-DAIs are indicated as 4.

In FIGS. 8 and 9, the HARQ-ACK codebook determination can operate under the assumption that only one PUCCH containing HARQ-ACK information is transmitted in one slot. As an example of how one PUCCH transmission resource is determined in one slot, when PDSCHs scheduled in different DCIs are multiplexed and transmitted as one HARQ-ACK codebook in the same slot, the PUCCH resource selected for HARQ-ACK transmission can be determined as the PUCCH resource indicated by the PUCCH resource field indicated in the DCI that last scheduled the PDSCH. That is, the PUCCH resource indicated by the PUCCH resource field indicated in the DCI scheduled before the DCI is ignored.

Below we describe a network-controlled repeater (NCR).

Coverage is one of the important factors in wireless communication systems. Currently, 5G systems are commercialized, and millimeter waves are also included as a technology element for commercialization, but actual use is not very high due to limited coverage. Many operators are looking for ways to provide stable coverage while also providing services economically.

A technology designed to find a more economical way to improve stable coverage in wireless communication systems is IAB (integrated access and backhaul), which has been studied across 3GPP Rel-16 and Rel-17. IAB is a kind of relay that does not require a wired backhaul network and can relay between base stations and terminals. IAB has similar performance to base stations, but the disadvantage is that the network cost increases due to the use of IAB.

Also, the existing RF repeater can be considered as a technology for improving stable coverage in a wireless communication system. The RF repeater is the most basic unit of repeater that performs the operation of amplifying and transmitting a signal coming from a communication device. Since the RF repeater simply performs the operation of amplifying and transmitting a signal, there is an advantage of reducing network costs when using the RF repeater, but there is a disadvantage of not being able to actively respond to various situations that may occur in the network. For example, since the RF repeater generally does not use a directional antenna but an omni-antenna, beamforming gain cannot be obtained when using the RF repeater. In addition, even when there is no terminal connected to the RF repeater, the RF repeater transmits a signal by amplifying noise, which can cause interference.

The above IAB and RF repeaters show clear advantages and disadvantages because they are biased toward one side between performance and cost. In reality, in order to increase coverage in a wireless communication system, not only performance but also cost must be considered, so there is a growing need for a new terminal or amplifier that considers both performance and cost.

Standardization is in progress for the so-called NCR, which improves coverage by enabling beamforming technology using adaptive antennas in RF repeaters while maintaining the amplification and transmission operations of RF repeaters. In order for NCR to transmit signals to terminals using adaptive antennas within a cell, NCR must be able to receive control signals from the base station. Therefore, NCR must be able to detect and decode the control signals of the base station, and can have a structure that enables transmission and reception of control signals similar to terminals. NCR can basically perform operations of amplifying signals transmitted from the base station and transmitting them to terminals, and amplifying signals transmitted from terminals and transmitting them to the base station. In other words, NCR does not detect or decode signals or channels transmitted and received by the base station and can only amplify and transmit the corresponding signals. Therefore, the terminal cannot know whether NCR is involved in the communication between the base station and the terminal. In other words, the terminal cannot distinguish between the base station and the NCR, and the NCR can appear to be a base station. Since the terminal does not need any additional information or operations for NCR, NCR can support any terminal.

As described above, from the perspective of the base station, the NCR can be seen as a general terminal. When the NCR is first installed in the network, the NCR can perform an initial connection to the base station like a general terminal and inform the base station that it is an NCR. After the base station confirms the NCR and a higher layer connection (e.g., RRC connection) is established between the base station and the terminal, the NCR can receive the settings necessary for amplification and transmission operations from the base station. From the perspective of the base station, it is necessary to know whether the terminal is directly connected to the base station or connected through the NCR for control. There are various implementations for determining whether the terminal served by the base station is within the NCR coverage or outside the NCR coverage.

The base station can know which terminal is communicating through which NCR, but the NCR cannot know which terminal is communicating through which NCR. The NCR can perform the operation of amplifying the signal and sending it to the terminal as controlled by the base station regardless of whether the terminal is in its coverage or not. In order for the base station to control the NCR, a dynamic control signal may be required.

FIG. 10 is a diagram illustrating an example of a transmission and reception operation of an NCR when the NCR relays between a base station and a terminal according to an embodiment of the present disclosure.

Referring to FIG. 10, an operation of NCR (1000) relaying communication (e.g., downlink, uplink) between a base station and a terminal is illustrated. NCR (1000) includes NCR-MT (network-controlled repeater-mobile termination, 1001) capable of transmitting and receiving control signaling of a base station, and NCR-Fwd (network-controlled repeater-forwarding, 1002) that amplifies and transmits a downlink signal or amplifies and transmits an uplink signal according to the control signaling of the base station. NCR-MT (1001) can receive control signaling from the base station through a control link (control link, C-link, 1003) and can transmit feedback information to the base station. That is, from the base station's perspective, NCR-MT (1001) appears as a general terminal, and the base station can perform communication with NCR-MT (1001) accordingly. The base station can control the NCR-Fwd (1002) by transmitting control signaling to the NCR-MT (1001).

NCR-Fwd (1002) can basically process RF signals and/or physical layer signals, and can perform an operation of amplifying a downlink signal received from a base station and transmitting it to a terminal. NCR-Fwd (1002) can perform an operation of receiving a signal from a base station through a backhaul link (1004) in the downlink and then transmitting it to a terminal through an access link (1005). In the example of Fig. 10, the backhaul link (1004) and the C-link (1003) are illustrated as individual links, but the backhaul link (1004) and the C-link (1003) may not necessarily be physically separate links.

NCR (1001) can detect/examine DCI set to control the operation of NCR (1001) from the base station while performing signal amplification and transmission, through C-link (1003). In the case of uplink, NCR (1001) can perform an operation of receiving an uplink signal transmitted by a terminal through an access link (1005), amplifying the uplink signal, and transmitting it to the base station through a backhaul link (1004). At this time, NCR (1001) can transmit uplink feedback or signal for DCI or upper layer signaling received from the base station to the base station. The backhaul link (1004) can be a wired link or a wireless link. In the embodiments of the present disclosure below, NCR can have a configuration such as the example of FIG. 10.

NCR can perform two operations on the backhaul link beam. The first operation is the default operation. The backhaul link beam of NCR can correspond to the beam of the smallest CORESET ID in the downlink, and can correspond to the beam of the smallest PUCCH ID in the uplink. In this case, when NCR-MT receives SSB, CSI-RS, PDCCH, PDSCH in C-link, or transmits PRACH, PUCCH, PUSCH, SRS (sounding reference signal), the beam of C-link is applied to the backhaul link symbol overlapping with the corresponding channel and/or signal. If the Unified TCI state is configured, the indicated Unified TCI state is applied to the backhaul link beam.

In the second operation, when the NCR transmits a capability report to the base station that it can receive backhaul link indication with MAC-CE, the base station can indicate the beam of the backhaul link with MAC-CE. The MAC-CE includes TCI state ID or SRI. When the NCR is indicated the backhaul link beam with the corresponding MAC-CE, the indicated beam is applied until the beam is updated with an additional MAC-CE. At this time, when the NCR-MT receives SSB, CSI-RS, PDCCH, PDSCH, or transmits PRACH, PUCCH, PUSCH, SRS on the C-link, the beam of the C-link is applied to the backhaul link symbol that overlaps with the corresponding channel and/or signal.

NCR can receive instructions for access link beams via C-link. NCR can receive periodic, semi-persistent, and aperiodic instructions. Access link beam instructions are described in FIGS. 11a, 11b, and 11c below.

FIG. 11A is a diagram illustrating an example in which an NCR receives a beam instruction for a periodic access link from a base station. Referring to FIG. 11A, an NCR may be configured with one or more forwarding lists (forwarding lists, 11-01) by upper layer signaling (11-00). Each forwarding list includes one or more forwarding resources (forwarding resources, 11-02). And each forwarding resource includes one access link beam index and one time resource. In this case, the access link beam index is an index corresponding to a physical beam that can be applied in uplink and downlink in the access link of the NCR. In addition, the time resource includes time information (e.g., slot offset, symbol offset, and symbol duration) to which the access link beam is to be applied. In addition to the forwarding resource, the forwarding list may include a periodicity and an SCS. If the NCR is set to the above upper layer signaling, it will be able to operate as in 11-20. 11-20 shows an example of List0. The NCR can refer to List0, apply the access link beam index 0 according to the given subcarrier interval in the time domain of 11-22, and perform the amplification and forwarding operation. In the same way, the NCR can apply the access link beam indices 1 and 2 in 11-23 and 11-24 to perform the amplification and forwarding operation. The forwarding resources of List0 can be continuously repeated according to the period (11-21).

FIG. 11b is a diagram illustrating an example in which an NCR receives a beam instruction for a semi-persistent access link from a base station. The difference between the periodic access link beam instruction of FIG. 11a and the beam instruction for a semi-persistent access link is that the periodic access link beam instruction is activated as soon as it is set by upper layer signaling, whereas the semi-persistent access link beam instruction requires that the corresponding forwarding resource be activated by MAC-CE. The NCR can set a forwarding list and forwarding resources to be applied to a semi-persistent access link beam index by upper layer signaling (11-30). The relationship between the forwarding list and the forwarding resources is the same as the periodic instruction of FIG. 11a. When the NCR is instructed to activate List0 from the base station with MAC-CE (11-70), the NCR can refer to List0 instructed by MAC-CE as 11-50, apply access link beam index 0 according to the given subcarrier interval in time domain as 11-52, and perform amplification and forwarding operations. In the same manner, the NCR can apply access link beam indices 1 and 2 in 11-53 and 11-54 to perform amplification and forwarding operations. The forwarding resources of List0 can be continuously repeated according to the cycle (11-51). If the NCR receives a deactivation instruction of List0 with MAC-CE (11-70), the cycle is not repeated any more.

FIG. 11C is a diagram illustrating an example in which an NCR receives a beam indication for an aperiodic access link from a base station. The aperiodic access link beam indication of FIG. 11C differs from the periodic/semi-persistent access link beam indications of FIGS. 11A and 11B in that the NCR dynamically receives the access link beam indication with DCI, and the indication does not have a corresponding period. The NCR can set the number of access link beams applicable to the aperiodic access link beam indication, the time resource list, and the number of fields of beam index and time index included in the DCI through upper layer signaling (11-80). FIG. 11C illustrates an example in which the DCI includes three beam index fields and three time index fields, but the present invention is not limited to such an example.

If the NCR detects a DCI scrambled with an NCR-specific RNTI (e.g., DCI format 2_8, 11-85), the NCR can refer to the beam index field and the time index field indicated by the DCI. The beam index field indicates an access link beam index, and the time index field indicates an entry or resource ID of a time resource list set in the upper layer signaling (11-80). The beam index field and the time index field always have the same number of fields and have a 1:1 mapping. Through the combination of the beam index field and the time index field, the NCR can receive an access link beam indication, such as 11-20, by the DCI (11-85). Specifically, as in 11-90, the NCR can apply the access link beam index 0 as indicated by the DCI (11-85) according to the given subcarrier interval in the 11-92 time domain and perform an amplification and transmission operation. In the same way, NCR can perform amplification and forwarding operations by applying access link beam indices 1 and 2 at 11-93 and 11-94. This operation is not repeated.

It may not be explicitly communicated to the NCR whether the access link beam indicated is for uplink or downlink. In this case, the NCR may determine the direction of the access link beam according to the uplink or downlink indicated by the higher layer signaling tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated which may be specified in the 3GPP standard TS 38.331. If a flexible symbol other than uplink or downlink is indicated, the NCR may not perform the amplification and forwarding operation.

<Example 1: Method for setting passband>

The NCR receives a control signal with the NCR-MT and performs an amplification and transmission operation. At this time, since the control signal is transmitted through the PDSCH or PDCCH in the same way as the existing terminal, it is more advantageous in terms of hardware complexity for the band of the NCR-MT and the band performing the amplification and transmission operation to be the same. Therefore, the existing NCR expects that the band of the NCR-MT and the passband overlap. The passband is a frequency band where the amplification and transmission operation is performed, and can be a frequency band where the backhaul link and the access link exist, and is assumed to be continuous. In addition, the existing NCR assumes that the band of the NCR-MT and the passband always operate in the same band.

FIG. 12 is a diagram illustrating an example of an NCR-MT band and a passband according to an embodiment of the present disclosure. Referring to FIG. 12, it can be seen that a conventional NCR expects an operation such as 12-00. In 12-00, an example is illustrated in which the NCR-MT band (12-03) and the passband (12-01) overlap and are included in the same frequency band (12-04). In terms of frequency band, since it is assumed that the NCR-MT band (12-03) and the passband (12-01) always overlap and the same band is used, a conventional NCR can only be instructed with time information (e.g., time resource) of an access link beam described in at least FIGS. 11a, b, and c, and frequency information may not be included.

If the conventional NCR operates as in 12-10, the NCR will always apply the beam or perform the amplification and transmission operation in the 12-05 passband and the 12-06 passband together. If the NCR can operate separately in each passband by distinguishing 12-05 and 12-06, the power consumption of the NCR can be reduced and interference can be lowered. For example, if the NCR performs the transmission operation in the several GHz band, but the served terminal needs only a few tens of MHz band, always transmitting the signal in the entire band will result in power waste and interference. The operation of transmitting only the necessary frequency band can be advantageous to the NCR.

In general, NCR can operate only within a band in which the NCR-MT band and the passband band are one band. If the NCR operates in a high frequency band such as the FR2 band, the reliability of receiving control signals may deteriorate due to high path loss and linearity of the signal. For example, a case in which the band and passband of NCR-MT are located in Band#A and Band#B, respectively, such as NCR 12-20, can be considered. If the band and passband of NCR-MT can be operated separately so that they are located in different bands, the reliability can be improved and the performance can be increased. For example, if the NCR-MT receives a control signal from the base station in the FR1 band and the passband is located in the FR2 or a band where a wideband is supported, the reliability of receiving the control signal can be increased. In addition, if NCR can perform signal transmission operation simultaneously or through time division through passbands located in different bands Band#A and Band#B, such as 12-30, NCR can increase the reliability of signals transmitted and received by terminals and further increase performance.

In conclusion, if NCR can support the operation of selectively applying multiple passbands or can support inter-band operation of the band and passband of NCR-MT, power consumption reduction, interference reduction, reliability increase, and performance improvement can be expected. In order to support the above operations, the operation of NCR recognizing the passband ID by setting the passband is required. In addition, additional operation definitions will be required for the access link beam and the backhaul link beam for the selective passband and interband operations. The following description describes how NCR sets the passband.

Since the configuration for conventional NCR does not include the configuration for the passband, it is not expected to perform selective amplification and transmission operations in the frequency band under the control of the base station. In order to control the passband of the NCR under the control of the base station, the base station needs to proactively acquire the passband information of the NCR. The method for the base station to acquire the passband information of the NCR can be as follows.

- Method 1 is that the NCR transmits a capability report containing information about the passband to the base station, and the base station sets the passband. When the connection between the base station and the NCR is established, the base station establishes radio resources for the NCR by requesting information about the capability from the NCR. In order for the network to manage the NCR thereafter, terminal capability reporting is continuously required. The terminal capability reporting procedure of the NCR can be the same as the operation of the existing terminal.

FIG. 13 is a diagram illustrating an example of a capability report of an NCR including passband information according to an embodiment of the present disclosure. Referring to FIG. 13, an operation of an NCR performing a capability report (13-00) is illustrated. The NCR may transmit information about each passband as a bundle in order to report information about one or more passbands. For example, the NCR may report an information bundle (13-02) about a passband by indexing (13-01). If there is no index, it may be inferred that the index is specified in the order of the information bundles. The information included in the information bundle (13-02) included in the capability report (13-00) may include at least one of the following:

- Band number

- CC (component carrier)

- Start CRB(common resource block)

- CRB size

Through the above information bundle, the base station will be able to know which passband of the NCR is located in which frequency domain. In addition, the NCR may report intra-band or inter-band NCR capability in addition to the above information. Intra-band capability may mean that the band and the passband of the NCR-MT are located in the same band. The NCR that performed the intra-band capability report may expect that the band and the passband of the NCR-MT are always located in the same band. On the other hand, inter-band capability may mean that the band and the passband of the NCR-MT may be located in different bands. The network may set the band and the passband of the NCR-MT of the NCR that performed the inter-band capability report to different bands. Based on the capability report of the NCR, the network may decide whether to set the passband to be located in the same band as the NCR-MT band or in a different band. In the above, the band may mean a frequency band defined in a standard such as TS 38.101, or may mean a frequency range (FR). As an example, FR1 in the above may be understood as a frequency band of 410 MHz to 7.125 GHz, FR2 as a frequency band of 24.25 GHz to 71.0 GHz, FR3 as a frequency band of 7.125 GHz to 24.25 GHz, and FR4 as a frequency band of 71.0 GHz to 114.25 GHz, but obvious modifications are also possible. In addition, the terminal capability report may include information related to an access link beam that can be supported by the NCR and information related to an access link beam that can be supported in each passband.

- After the NCR reports the capability (13-00), the base station can perform passband configuration (13-10). The passband configuration information can be transmitted from the base station to the NCR through upper layer signaling (e.g. RRC). The passband configuration of the base station can include at least one of the following information:

- Passband ID: The passband ID can be viewed as a unique identifier for each passband. If a mapping index is set, the passband ID can point to multiple non-contiguous frequency bands. In this case, the passband ID can mean an identifier of a set that includes multiple passbands.

- Mapping index: The mapping index can be used when one passband ID indicates multiple frequency bands. For example, passband ID0 set to 13-10 corresponds to passband index 0 of 13-01 reported by the terminal, and passband ID2 can correspond to both passband index 0 and 1. If the mapping index is not set, it can be expected that the passband IDs are mapped one-to-one with the information bundles included in the capability report in order. That is, passband ID0 can correspond to passband index 0, and passband ID1 can correspond to passband index 1.

The NCR will be able to know the minimum passband ID and the corresponding frequency band information from the above passband configuration. If the NCR does not receive any configuration for the passband, the NCR can always be expected to apply the access link beam or perform the amplify and forward operation for all passbands.

Method 2 is that information about the passband of the NCR is disclosed according to the specifications of the manufacturers, and each operator sets the passband with an internal implementation (for example, an OAM (operation and maintenance) server). The passband can be set for the base station and the NCR according to the internal procedures of the operators. In this case, the base station can additionally set the passband to actually be used by sending upper layer signaling to the NCR. It can be expected that the above settings will at least include the passband ID. According to Method 2, the use of one or more passbands can be performed by the internal implementation without standard support, but the problem may arise that each operator must support a specialized NCR due to the difference in implementation between operators.

<Second embodiment: Frequency selective access link beam indication method>

When an access link beam indication is given, the NCR can expect that the indication includes at least an access link beam index and a time resource. Meanwhile, in order for the base station to operate the NCR frequency selectively, it must indicate which passband is to be activated in which time resource. For example, the base station may use the passband ID described above to indicate to the NCR the frequency resource to be activated. The following description describes a method for indicating passband activation when the NCR receives an access link beam indication from the base station. The method can be as follows.

Method 1 is that the NCR receives the relationship between the passband and the access link beam index from the base station through upper layer signaling (e.g. RRC). Method 1 is a method in which a link between the access link beam index and the passband is established without additional configuration for the physical layer, and when the corresponding access link beam is indicated, the corresponding passband is activated.

FIG. 14 is a diagram illustrating an example of setting a passband and an access link beam index according to an embodiment of the present disclosure. Refer to Method 1-1 (14-00) and Method 1-2 (14-10) in FIG. 14.

Method 1-1 (14-00) is a method in which a passband ID is set as a sub-setting of each access link beam index. NCR can be set with an NCR-BeamConfig information element that sets a relationship between an access link beam index and a passband ID. The above terms are used arbitrarily for convenience and can be replaced with other terms having the same meaning. Up to N access link beam indices can be set by NCR-BeamConfig. And for each beam index, information on at least one passband ID corresponding to each beam index can be set. If NCR receives one of periodic/semi-persistent/aperiodic access link beam instructions, NCR can perform an amplification and transmission operation in a frequency band corresponding to the passband ID by referencing the passband ID set in the sub-category with reference to the corresponding beam index of NCR-BeamConfig. For example, if the NCR is instructed to have beam index 0 by at least one of the methods of FIGS. 11a to 11c, the NCR can perform amplification and transmission operations in passband IDs 0 and 1 corresponding to the beam index 0.

Method 1-2 (14-10) is a method in which an access link beam index is set as a sub-setting of a passband ID setting. This is a method in which an access link beam index is included in sub-information of a system setting including frequency and/or time resources. An NCR can receive PassbandConfig, which is an information element of a passband ID that can be activated. PassbandConfig can correspond to the passband setting (13-10) described above. The above terms are arbitrarily used for convenience and can be replaced with other terms having the same meaning. PassbandConfig can include a plurality of passband IDs, and sub-information of each passband ID can include at least one access link beam index. In addition, an access link beam index can be included in different passband IDs. For example, beam index 0 can be included in sub-information of both passband IDs 0 and 1. At this time, if the NCR is instructed with beam index 0 by at least one of the methods of FIGS. 11a to 11c, the NCR can perform amplification and transmission operations in passband IDs 0 and 1. Alternatively, if the NCR is instructed with beam index 2 by at least one of the methods of FIGS. 11a to 11c, the NCR can perform amplification and transmission operations in passband ID 1.

The above-described methods 1-1 and 1-2 are methods for setting the relationship between the beam index and the passband in the upper layer regardless of the periodic/semi-persistent/aperiodic access link beam instructions. According to methods 1-1 and 1-2, the passband can be consistently controlled for all access link beam instructions, so it can be easy to apply from the network's perspective. However, in order to change the relationship between the passband and the access link beam, re-setting must be performed by upper layer signaling that takes a long processing time, so the access link beam cannot be dynamically changed for the required channel and/or signal. Therefore, a method for defining the passband to be activated for each periodic/semi-persistent/aperiodic access link beam applicable to each channel and/or signal may be required.

Method 2 is a method of indicating which passband will be activated for each periodic/semi-persistent/aperiodic access link beam. Method 2 can be divided into periodic/semi-persistent/aperiodic.

- Periodic method 2-1: When a periodic access link beam is used, the NCR may be configured with one or more forwarding lists by upper layer signaling. Each forwarding list may include one or more forwarding resources. And each forwarding resource may include one access link beam index, one time resource, and one or more passband IDs. If there is a forwarding resource configuration that does not include a passband ID, the forwarding resource may be considered to activate passbands according to all passband IDs configured in the upper layer. If a specific passband ID is not included in any forwarding resource in the forwarding list, the NCR may expect that the specific passband ID is included in the forwarding list at least once. That is, a passband ID corresponding to a forwarding list, rather than a specific forwarding resource, may be included in the forwarding list configuration, in which case the included passband ID may be considered to correspond to all forwarding resources included in the forwarding list configuration.

- Semi-persistent method 2-2: NCR can be configured with one or more forwarding lists to be applied to the semi-persistent access link beam index by upper layer signaling. Each forwarding list can include one or more forwarding resources. And each forwarding resource can include one access link beam index, one time resource, and one or more passband IDs. If there is a forwarding resource configuration that does not include a passband ID, the forwarding resource can be considered to activate passbands according to all passband IDs configured in the upper layer. If a specific passband ID is not included in any forwarding resource in the forwarding list, NCR can expect that the specific passband ID is included in at least one forwarding list. That is, a passband ID corresponding to a forwarding list, not a specific forwarding resource, can be included in the forwarding list configuration, and in this case, the included passband ID can be considered to correspond to all forwarding resources included in the forwarding list configuration.

The NCR may be instructed to activate or deactivate one of the forwarding lists by the MAC-CE. In general, the semi-persistent access link beam is instructed for the purpose of amplifying and forwarding the semi-persistent channel and/or signal of the served terminal. Therefore, the passband ID may need to be updated depending on the situation. If the passband ID exists for each forwarding resource, one or more forwarding resource entries or IDs and the passband ID may be instructed in the MAC-CE to be mapped one-to-one. The forwarding resource indicated by the MAC CE may be a forwarding resource included in one or more forwarding lists. If there is no passband ID setting corresponding to any forwarding resource and the passband ID is set only for the forwarding list, the MAC-CE may include one or more passband IDs and the number of passbands indicated (for a specific forwarding list). The NCR may update the activated passband based on the passband information included in the MAC-CE to perform the amplification and forwarding operation. If no passband information exists in MAC-CE, NCR may activate the passband information set by upper layer signaling.

- Aperiodic method 2-3: Aperiodic methods can be divided into two types. The first method, 2-3-1, is a method in which the NCR is instructed to set the passband information through upper layer signaling and updates it with DCI as needed. The second method, 2-3-2, is a method in which the passband information can be obtained only from DCI. The two methods are as follows.

Method 2-3-1: NCR can be configured with the number of access link beams applicable to aperiodic access link beam indication through upper layer signaling, a time resource list, and the number of beam index and time index fields included in DCI. The time resource list configured in the upper layer signaling includes at least one time resource. And the time resource can include a slot offset, a symbol offset, a symbol length, and at least one passband ID.

If the NCR detects a DCI scrambled with an NCR-specific RNTI (for example, DCI format 2_8), the NCR may refer to the time index field. The time index field includes an entry or ID of a time resource list. The NCR may check a passband ID corresponding to the time resource indicated in the time resource field of the detected DCI, and perform an amplification and forwarding operation in the corresponding frequency band indicated by the passband ID. The aperiodic access link beam indication is to respond to the dynamic traffic of the serving terminal, and if necessary, the NCR may need to use a passband other than the passband set by the upper layer signaling. In this case, the NCR may receive a setting that the DCI includes a passband ID by the upper layer signaling, and perform an amplification and forwarding operation in the passband indicated by the passband ID. That is, if the passband update by the DCI is set by the upper layer signaling, the NCR may prioritize at least one passband ID included in the DCI. The passband ID included in the DCI may be applied to all time resources indicated by the DCI.

Method 2-3-2: If the NCR detects a DCI scrambled with an NCR-specific RNTI (for example, DCI format 2_8), the NCR may detect at least one passband ID field included in the DCI. The number of passband ID fields included in the DCI may be configured by upper layer signaling. The passband indicated by the DCI may be applied equally to all indicated time resources, or alternatively, the number of passband ID fields may always be equal to the number of time resource fields, and the passband ID field and the time resource field may be mapped one-to-one. In this case, different passbands may be applied to each time resource. For example, if DCI includes passband ID field 1 and passband ID field 2, time resource field 1 and time resource field 2, the passband indicated by passband ID field 1 may be activated in the time resource indicated by time resource field 1, and the passband indicated by passband ID field 2 may be activated in the time resource indicated by time resource field 2. In this case, the passband ID field may indicate one or more passband IDs.

The above-described methods 1 and 2 are both methods for performing passband activation associated with an access link beam index and indication. Another method is a method for indicating passband activation independently of an access link beam. Method 3, which is a method for indicating passband activation independently of an access link beam, is as follows.

FIG. 15 is a diagram illustrating an example of an independent passband indication according to an embodiment of the present disclosure. Referring to FIG. 15, an example of an operation of an NCR activating a passband (15-01, 15-02) by being instructed by a MAC-CE or DCI (15-00) is illustrated. The MAC-CE or DCI may be different from a MAC-CE or DCI indicating an access link beam. The MAC-CE or DCI received by the NCR for passband activation may include at least one passband ID. When the NCR is instructed by a passband ID by the MAC-CE or DCI, the instructed passband may be activated after a given slot offset. For example, when the NCR receives a MAC-CE indicating passband activation from a base station, the first slot after a PUCCH transmitting a HARQ-ACK for a PDSCH including the MAC-CE may be a reference for the offset. When the NCR receives a DCI indicating passband activation, the slot of the PDCCH conveying the DCI can be used as the offset reference. Once the passband indicated by MAC-CE or DCI is activated, it can remain activated until further instructions are given.

Depending on the demand of the terminal served by the NCR, the passband of the NCR may need to be switched. When the NCR receives MAC-CE or DCI indicating multiple passbands, the passband indicated later in the time axis may have priority. For example, if the base station indicates passband 0 (15-01) at 15-00 and then indicates passband 1 (15-02) at 15-10, passband 1 will be activated. In the same way, if passbands 0 and 1 are indicated at 15-20, passbands 0 and 1 will be activated. It can be assumed that all configured passbands are activated before an indication is given by MAC-CE or DCI.

<Third embodiment: Interband backhaul link beam operation method>

As described above, if the band and passband of the NCR-MT are located in different bands, such as 12-20 or 12-30 of FIG. 12, and the NCR performs operations, reliability can be improved and performance can be increased. For example, if the NCR-MT receives a control signal in the FR1 band and the passband is located in the FR2 or a band that supports wideband, the reliability of the control signal can be increased. More specifically, in band #A of 12-20, the NCR-MT receives a control signal required for amplification and transmission through PDCCH monitoring, and performs amplification and transmission operations in band #B. For example, the base station can set band #A as PCell for the NCR-MT, set band #B as SCell, and then set the BWP of band #B as a dormant BWP. The NCR can perform channel measurement and beam management by receiving or transmitting signals such as SSB, CSI-RS, and SRS in band #A. However, since the dormant BWP is set in band #B, NCR-MT does not perform PDCCH monitoring, but measures downlink channels such as SSB or periodic CSI-RS, and the measurement results can be reported to the base station in the NCR-MT band of band #A.

When NCR operates in a band such as 12-20 or 12-30, access link beam indication can be possible according to the passband setting and frequency selective access link beam indication method described above. On the other hand, backhaul link beam operation can be ambiguous. When there is no traffic of NCR-MT, the backhaul link beam of a typical NCR can be obtained by applying the QCL of the CORESET with the lowest ID or by applying the spatial filter of the PUCCH with the lowest ID. The above operation can be possible under the assumption that the CORESET is set in the same band or CC and that the PUCCH can be transmitted.

However, if CORESET or PUCCH is not set in a band where the backhaul link is located, such as band #B of 12-20 or 12-30, the operation of the NCR using the backhaul link beam may be ambiguous. Even if the NCR tries to apply the beam of the CORESET or PUCCH set in the adjacent band, the applicable beam may differ depending on the frequency band. Therefore, the backhaul link beam of the passband operating in a band without a CORESET or PUCCH setting needs to be defined according to a different operation from the conventional operation. The operation of the backhaul link beam in a band without a CORESET or PUCCH setting is as follows.

- Method 1: If the TCI state is set for a band for which CORESET is not set, the NCR can use the TCI state with the smallest ID among the TCI states activated by MAC-CE as the downlink beam of the backhaul link. The uplink beam of the backhaul link can be obtained by reusing the spatial filter used when receiving a signal according to the TCI state as an uplink beam. The method assumes that the downlink channel is similar to the uplink channel (beam correspondence).

- Method 2: For a band for which CORESET is not set, the NCR will perform continuous channel measurement and beam management operations. The NCR can expect to receive, as the downlink beam of the backhaul link, the beam of the SSB or CSI-RS with the best RSRP among the SS-RSRP or CSI-RSRP measured and reported for the band. The uplink beam of the backhaul link can be obtained by reusing the spatial filter used when receiving the SSB or CSI-RS for the uplink beam purpose. The method assumes that the downlink channel is similar to the uplink channel (beam correspondence). If the assumption is not satisfied, the NCR can apply the spatial filter used for the PRACH most recently transmitted to the uplink beam of the backhaul link.

- Method 3: For the bands where CORESET is not set, the NCR can expect the base station to indicate the backhaul link beam with the MAC-CE. In other words, if the NCR is configured to perform interband operation, the NCR can expect to always receive the backhaul link beam indication with the MAC-CE for the bands where CORESET is not set. At this time, the MAC-CE indicating the backhaul link beam may include a passband ID. In addition, the base station can expect that the NCR will also report the capability of receiving the backhaul link beam indication with the MAC-CE when transmitting the capability report for the interband operation. The NCR can receive the backhaul link beam of the bands where CORESET is not set with the MAC-CE and perform the amplification and transmission operation after the indicated beam is applied.

Additionally, information on whether the above backhaul link beam operation of NCR is supported may be included in the terminal capability report and reported to the base station. The above information may also be reported together with the inter-band NCR capability report.

It is possible for the methods for the first to third embodiments described above to be performed by combining at least one method.

FIG. 16 is a flowchart illustrating an example of the operation of an NCR performing at least one embodiment of the present disclosure.

The NCR can transmit a terminal capability report to the base station (16-00). The terminal capability report can include at least one of passband information that the NCR can support, inter-band or/and intra-band NCR capability, access link beam related information or backhaul link beam support related information, and the contents described above can be referenced. In addition, the step can be omitted. The NCR can receive at least one of passband configuration information, access link beam configuration information or backhaul link beam configuration information from the base station (16-10). The configuration information can be based on the terminal capability report, and the details can follow the contents of the first to third embodiments described above.

After receiving the above setting information, the NCR can operate according to the above setting information (16-20). For example, the NCR can perform transmission and reception of channels and/or signals with the terminal using the access link beam indicated in the passband activated according to the above setting information.

The flowcharts described above illustrate exemplary methods that may be implemented in accordance with the principles of the present disclosure, and various modifications may be made to the methods illustrated in the flowcharts herein. For example, although illustrated as a series of steps, the various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

FIG. 17 is a flowchart illustrating an example of the operation of a base station performing at least one embodiment of the present disclosure.

The base station can receive a terminal capability report from the NCR (17-00). The terminal capability report can include at least one of passband information that the NCR can support, inter-band or/and intra-band NCR capability, access link beam related information or backhaul link beam support related information, and the contents described above can be referenced. In addition, the step can be omitted. The base station can transmit at least one of passband configuration information, access link beam configuration information or backhaul link beam configuration information to the NCR (17-10). The configuration information can be based on the terminal capability report, and the details can follow the contents of the first to third embodiments described above.

After receiving the above setting information, the NCR can operate according to the above setting information (17-20). For example, the base station can perform control information transmission to the NCR through the NCR-MT link and transmit a channel and/or signal to be transmitted to the terminal through the backhaul link.

The flowcharts described above illustrate exemplary methods that may be implemented in accordance with the principles of the present disclosure, and various modifications may be made to the methods illustrated in the flowcharts herein. For example, although illustrated as a series of steps, the various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

FIG. 18 is a block diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 18, the terminal may include a terminal receiving unit (18-00), a terminal transmitting unit (18-10), and a terminal processing unit (control unit) (18-05).

For example, as described above, the NCR, which relays between the terminal and the base station, appears to be a terminal from the base station's perspective, so in this case, the terminal in Fig. 18 may be an NCR. For example, the NCR may include a receiving unit, a transmitting unit, and a processing unit (control unit).

The terminal receiving unit (18-00) and the terminal transmitting unit (18-10) may be collectively referred to as a transceiver. Depending on the communication method of the terminal described above, the terminal receiving unit (18-00), the terminal transmitting unit (18-10), and the terminal processing unit (18-05) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components (e.g., memory, etc.) than the components described above. In addition, the terminal receiving unit (18-00), the terminal transmitting unit (18-10), and the terminal processing unit (18-05) may be implemented in the form of a single chip.

The terminal receiving unit (18-00) and the terminal transmitting unit (18-10) (or, transmitting and receiving unit) can transmit and receive signals with the base station. Here, the signals can include control information and data. To this end, the transmitting and receiving unit can be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal. However, this is only one embodiment of the transmitting and receiving unit, and the components of the transmitting and receiving unit are not limited to the RF transmitter and the RF receiver.

In addition, the transceiver can receive a signal through a wireless channel and output it to the terminal processing unit (18-05), and transmit a signal output from the terminal processing unit (18-05) through the wireless channel.

Memory (not shown) can store programs and data necessary for the operation of the terminal. In addition, the memory can store control information or data included in a signal obtained from the terminal. The memory can be composed of a storage medium such as ROM, RAM, a hard disk, CD-ROM, and DVD, or a combination of storage media.

The terminal processing unit (18-05) can control a series of processes so that the terminal can operate according to the embodiment of the present disclosure described above. The terminal processing unit (18-05) can be implemented as a control unit or one or more processors.

FIG. 19 is a block diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

Referring to FIG. 19, the base station may include a base station receiving unit (19-00), a base station transmitting unit (19-10), and a base station processing unit (control unit) (19-05).

For example, as described above, the NCR, which relays between the terminal and the base station, appears to be a base station from the terminal's perspective, so in this case, the base station of Fig. 21 may be an NCR. For example, the NCR may include a receiving unit, a transmitting unit, and a processing unit (control unit).

The base station receiving unit (19-00) and the base station transmitting unit (19-10) may be collectively referred to as a transceiver. Depending on the communication method of the base station described above, the base station receiving unit (19-00), the base station transmitting unit (19-10), and the base station processing unit (19-05) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components (e.g., memory, etc.) than the components described above. In addition, the base station receiving unit (19-00), the base station transmitting unit (19-10), and the base station processing unit (19-05) may be implemented in the form of a single chip.

The base station receiving unit (19-00) and the base station transmitting unit (19-10) (or, transmitting and receiving unit) can transmit and receive signals with the terminal. Here, the signals can include control information and data. To this end, the transmitting and receiving unit can be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal. However, this is only one embodiment of the transmitting and receiving unit, and the components of the transmitting and receiving unit are not limited to the RF transmitter and the RF receiver.

In addition, the transceiver can receive a signal through a wireless channel and output it to the base station processing unit (19-05), and transmit the signal output from the base station processing unit (19-05) through the wireless channel.

The memory (not shown) can store programs and data necessary for the operation of the base station. In addition, the memory can store control information or data included in a signal acquired from the base station. The memory can be composed of a storage medium such as ROM, RAM, a hard disk, CD-ROM, and DVD, or a combination of storage media.

The base station processing unit (19-05) can control a series of processes so that the base station can operate according to the embodiment of the present disclosure described above. The base station processing unit (19-05) can be implemented as a control unit or one or more processors.

FIG. 20 is a block diagram illustrating the structure of an NCR in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 20, the NCR may include an NCR processing unit (control unit) (20-00) and an NCR transceiver unit (20-10). The NCR processing unit (20-00) and the NCR transceiver unit (20-10) of the NCR may operate according to the communication method of the NCR described above. Specifically, the NCR processing unit (20-00) and the NCR transceiver unit (20-10) may perform the operations of the NCR-MT and NCR-fwd described above. However, the components of the NCR are not limited to the examples described above. For example, the NCR may include more or fewer components (e.g., memory, etc.) than the components described above. In addition, the NCR processing unit (20-00) and the NCR transceiver unit (20-10) may be implemented in the form of a single chip.

The NCR transceiver (20-10) can transmit and receive signals between the base station and the terminal. Here, the signals can include control information and data. For example, the NCR transceiver (20-10) can receive control information and a downlink signal for controlling the operation of the NCR from the base station, amplify and transmit an uplink signal of the terminal to the base station, and transmit feedback information and/or SRS for signaling of the base station. In addition, the NCR transceiver can receive an uplink signal from the terminal and amplify and transmit a downlink signal of the base station to the terminal. To this end, the NCR transceiver (20-10) can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-converts a received signal. However, this is only one embodiment of the transceiver, and the components of the NCR transceiver (20-10) are not limited to the RF transmitter and the RF receiver.

The memory (not shown) can store programs and data necessary for the operation of the base station. In addition, the memory can store control information or data included in a signal acquired from the base station. The memory can be composed of a storage medium such as ROM, RAM, a hard disk, CD-ROM, and DVD, or a combination of storage media.

The NCR processing unit (20-00) can control a series of processes so that the NCR can operate according to the example of the present disclosure described above. The NCR processing unit (20-00) can be implemented as a control unit or one or more processors.

Meanwhile, the order of description in the drawings explaining the method of the present disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

Alternatively, the drawings illustrating the method of the present disclosure may omit some components and include only some components without damaging the essence of the present disclosure.

In addition, the method of the present disclosure may be implemented by combining part or all of the contents included in each embodiment within a scope that does not harm the essence of the disclosure. For example, it goes without saying that part or all of one or more embodiments may be combined with part or all of one or more other embodiments.

Additionally, although not disclosed in the present disclosure, a method is also possible in which a separate table or information including at least one component included in the table proposed in the present disclosure is used.

Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are only specific examples presented to easily explain the technical content of the present disclosure and help in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it is obvious to those skilled in the art to which the present disclosure pertains that other modified examples based on the technical idea of the present disclosure are possible. In addition, each of the above embodiments can be combined and operated as needed.

Claims (15)

In a method of performing a network-controlled repeater (NCR) of a wireless communication system, A step of transmitting capability information about a passband that the NCR can support to a base station; and Comprising a step of receiving upper layer signaling including configuration information for the passband from the base station, The above passband is a band that includes the backhaul or/and access link of the NCR, A method characterized in that the above capability information includes at least one of a band number for one or more passbands, frequency band resource information, and inter-band capability information and/or intra-band capability information of the NCR. In the first paragraph, A method characterized in that the above upper layer signaling includes information indicating an identifier of a passband set to the NCR and one or more frequency bands corresponding to the identifier. In the second paragraph, The above upper layer signaling includes access link beam setup information, A method characterized in that the above access link beam setting information includes an index of one or more access link beams and an identifier of one or more passbands corresponding to each access link beam. In the second paragraph, The above upper layer signaling includes access link beam setup information, A method characterized in that the above access link beam setting information includes an identifier of one or more passbands and an index of one or more access link beams corresponding to the identifier of each passband. In a method performed by a base station of a wireless communication system, A step of receiving capability information about a passband that the NCR can support from a network-controlled repeater (NCR); and Comprising a step of transmitting upper layer signaling including configuration information for the passband to the NCR, The above passband is a band that includes the backhaul or/and access link of the NCR, A method characterized in that the above capability information includes at least one of a band number for one or more passbands, frequency band resource information, and inter-band capability information and/or intra-band capability information of the NCR. In paragraph 5, A method characterized in that the above upper layer signaling includes information indicating an identifier of a passband set to the NCR and one or more frequency bands corresponding to the identifier. In Article 6, The above upper layer signaling includes access link beam setup information, A method characterized in that the above access link beam setting information includes an index of one or more access link beams and an identifier of one or more passbands corresponding to each access link beam. In Article 6, The above upper layer signaling includes access link beam setup information, A method characterized in that the above access link beam setting information includes an identifier of one or more passbands and an index of one or more access link beams corresponding to the identifier of each passband. In the NCR (network-controlled repeater) of a wireless communication system, Transmitter and receiver; and Transmit capability information about the passband that the NCR can support to the base station, A control unit configured to receive upper layer signaling including configuration information for the passband from the base station, The above passband is a band that includes the backhaul or/and access link of the NCR, An NCR, characterized in that the above capability information includes at least one of a band number for one or more passbands, frequency band resource information, and inter-band capability information and/or intra-band capability information of the NCR. In Article 9, An NCR, characterized in that the above upper layer signaling includes information indicating an identifier of a passband set to the NCR and one or more frequency bands corresponding to the identifier. In Article 10, The above upper layer signaling includes access link beam setup information, An NCR characterized in that the above access link beam setting information includes an index of one or more access link beams and an identifier of one or more passbands corresponding to each access link beam. In Article 10, The above upper layer signaling includes access link beam setup information, An NCR characterized in that the above access link beam setting information includes an identifier of one or more passbands and an index of one or more access link beams corresponding to the identifier of each passband. In a base station of a wireless communication system, Transmitter and receiver; and Receive capability information about the passband that the NCR can support from the NCR (network-controlled repeater), A control unit configured to transmit upper layer signaling including configuration information for the passband to the NCR; The above passband is a band that includes the backhaul or/and access link of the NCR, A base station, characterized in that the above capability information includes at least one of a band number for one or more passbands, frequency band resource information, and inter-band capability information and/or intra-band capability information of the NCR. In Article 13, A base station, characterized in that the above upper layer signaling includes information indicating an identifier of a passband set to the NCR and one or more frequency bands corresponding to the identifier. In Article 14, The above upper layer signaling includes access link beam setup information, The above access link beam configuration information includes an index of one or more access link beams and an identifier of one or more passbands corresponding to each access link beam, or A base station, characterized in that the above access link beam setting information includes an identifier of one or more passbands and an index of one or more access link beams corresponding to the identifier of each passband.

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