Method and apparatus for transmitting / receiving data for network cooperative communication

Abstract

The present disclosure relates to a communication technology for converging an IoT technology with a 5G communication system to support a higher data transmission rate beyond a 4G system, and a system therefor. The present disclosure may be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and security-related services, etc.) based on 5G communication technology and IoT-related technology. The present disclosure relates to a method and apparatus for performing cooperative communication in a wireless communication system. The method of a terminal of a communication system includes: receiving transmission configuration indicator (TCI) state information from a base station; and identifying a quasi co-located QCL reference signal associated with TCI state information, where the TCI state information indicates a synchronization signal block (SSB) as the QCL reference signal, where the TCI state information includes information indicating a physical cell identity (PCI) of the SSB, and where the PCI of the SSB is different from the PCI of the serving cell.

Description

[0001] This application is a divisional application of a patent application with an application date of September 28, 2020, application number 202080067994.2, and invention name “Method and device for sending / receiving data for network collaborative communication”. Technical Field

[0002] The present disclosure relates to a method and apparatus for performing communication in a wireless communication system, and more particularly, to a method and apparatus for performing cooperative communication. Background Art

[0003] In order to meet the growing demand for wireless data communication volume since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also called "super 4G network" communication systems or "post-LTE" systems. 5G communication systems are considered to be implemented in higher frequency (millimeter wave) bands (for example, 60GHz bands) in order to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple input multiple output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technology are discussed in 5G communication systems. In addition, in 5G communication systems, system network improvements are being developed based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, collaborative communications, coordinated multipoint (CoMP), receiving-end interference cancellation, etc. In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coding modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0004] The Internet, a human-centric connected network where humans generate and consume information, is now evolving into the Internet of Things (IoT), in which distributed entities (such as things) exchange and process information without human intervention. The Internet of Everything (IoE) has emerged, combining IoT technologies with big data processing technologies through connectivity to cloud servers. As technological elements such as "sensing technology," "wired / wireless communication and network infrastructure," "service interface technology," and "security technology" have become essential for IoT implementation, research has recently focused on sensor networks, machine-to-machine (M2M) communication, and machine-type communication. This IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated by connected things. Through the convergence and integration of existing information technology (IT) and various industrial applications, the IoT can be applied in a variety of fields, including smart homes, smart buildings, smart cities, smart cars or connected vehicles, smart grids, healthcare, smart appliances, and advanced medical services.

[0005] In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-type communications (MTC), and machine-to-machine (M2M) communications can be implemented through beamforming, MIMO, and array antennas. Cloud radio access networks (RANs), as an application of the aforementioned big data processing technologies, can also be considered an example of the convergence of 5G and IoT technologies.

[0006] With the development of wireless communication systems as described above, a data transmission / reception method for network cooperative communication is required. Summary of the Invention

[0007] Technical issues

[0008] Based on the above discussion, the present disclosure provides a method and apparatus for transmitting and receiving signals between a transmission node and a UE to perform cooperative communication in a wireless communication system.

[0009] Technical Solution

[0010] According to an embodiment of the present disclosure, a method for a UE in a communication system may include: receiving cell configuration information from a base station associated with a first cell, the cell configuration information including a transmission configuration indicator (TCI) configuration and a quasi co-location (QCL) configuration; identifying a QCL reference antenna port based on the cell configuration information; and receiving a signal from the base station based on a QCL relationship with the identified QCL reference antenna port, wherein the QCL reference antenna port may be identified based on a synchronization signal block (SSB) or a channel state information reference signal (CSI-RS) associated with a second cell.

[0011] According to an embodiment, the first cell and the second cell may correspond to different physical cell identities (PCIs).

[0012] According to an embodiment, the TCI configuration or the QCL configuration may include information about a physical cell identity (PCI) corresponding to the second cell, and the QCL reference antenna port may be identified based on an SSB associated with the PCI corresponding to the second cell.

[0013] According to an embodiment, the TCI configuration or the QCL configuration may include information about a CSI-RS index associated with the second cell included in the CSI-RS configuration for mobility, and the QCL reference antenna port may be identified based on the CSI-RS corresponding to the CSI-RS index associated with the second cell.

[0014] According to an embodiment, the signal received from the base station may include at least one of a reference signal, data, and a control signal, and the reference signal may include a tracking reference signal (TRS).

[0015] According to an embodiment, the QCL reference antenna port can be identified based on the SSB or CSI-RS associated with the second cell depending on whether the UE performs inter-cell multi-TRP operation.

[0016] According to an embodiment, whether the UE performs inter-cell multi-TRP operation can be identified based on the UE's capability report or the SSB configuration received from the base station.

[0017] According to an embodiment, the SSB or CSI-RS associated with the second cell may be related to a reference signal for channel state measurement.

[0018] According to an embodiment, the SSB or CSI-RS associated with the second cell may be related to a beam failure detection (BFD) reference signal or a candidate beam detection (CBD) reference signal.

[0019] According to an embodiment of the present disclosure, a method for a base station in a communication system may include: sending cell configuration information to a UE, the cell configuration information including a transmission configuration indicator (TCI) configuration and a quasi co-location (QCL) configuration; and sending a signal to the UE based on a QCL relationship with a QCL reference antenna port identified based on the cell configuration information, wherein the QCL reference antenna port can be identified based on a synchronization signal block (SSB) or a channel state information reference signal (CSI-RS) associated with a second cell.

[0020] According to an embodiment of the present disclosure, a UE in a wireless communication system may include: a transceiver; and a controller, configured to: receive cell configuration information from a base station associated with a first cell, the cell configuration information including a transmission configuration indicator (TCI) configuration and a quasi co-location (QCL) configuration, identify a QCL reference antenna port based on the cell configuration information, and receive a signal from the base station based on a QCL relationship with the identified QCL reference antenna port, wherein the QCL reference antenna port can be identified based on a synchronization signal block (SSB) or a channel state information reference signal (CSI-RS) associated with a second cell.

[0021] According to an embodiment of the present disclosure, a base station in a communication system may include: a transceiver; and a controller, configured to: send cell configuration information to a UE, the cell configuration information including a transmission configuration indicator (TCI) configuration and a quasi co-location (QCL) configuration, and send a signal to the UE based on a QCL relationship with a QCL reference antenna port identified based on the cell configuration information, wherein the QCL reference antenna port can be identified based on a synchronization signal block (SSB) or a channel state information reference signal (CSI-RS) associated with a second cell.

[0022] Advantageous Effects of the Invention

[0023] According to the present disclosure, when network cooperative communication is used in a wireless communication system, the UE can improve the reliability of data / control signals transmitted or received through repeated transmission between transmission points, or can increase the transmission capacity of data / control signals transmitted or received through separate (independent) transmission for each transmission point. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The basic structure of a time-frequency domain as a radio resource region for transmitting data or a control channel in a 5G system according to an embodiment of the present disclosure is shown;

[0025] Figure 2 The structure of frames, subframes, and time slots in a 5G system according to an embodiment of the present disclosure is shown;

[0026] Figure 3 1. The configuration of a BWP in a wireless communication system according to an embodiment of the present disclosure is shown;

[0027] Figure 4 A method for dynamically changing the configuration of a BWP according to an embodiment of the present disclosure is shown;

[0028] Figure 5 A control resource set (CORESET) for transmitting a downlink control channel in a 5G system according to an embodiment of the present disclosure is shown;

[0029] Figure 6 The present invention shows a method for allocating PDSCH frequency domain resources in an NR system according to an embodiment of the present disclosure.

[0030] Figure 7 A method for allocating time domain resources of a physical downlink shared channel (PDSCH) in a wireless communication system according to an embodiment of the present disclosure is shown;

[0031] Figure 8 A method for allocating time domain resources according to a subcarrier spacing of a data channel and a subcarrier spacing of a control channel in a wireless communication system according to an embodiment of the present disclosure is shown;

[0032] Figure 9 The present invention shows a radio protocol structure of a base station and a UE when performing single cell, carrier aggregation (CA), and dual connectivity (DC) according to an embodiment of the present disclosure;

[0033] Figure 10 shows a cooperative communication antenna port configuration according to an embodiment of the present disclosure;

[0034] Figure 11 shows an example of configuring and indicating TCI status according to an embodiment of the present disclosure;

[0035] Figure 12 shows an example of configuring and indicating TCI status according to another embodiment of the present disclosure;

[0036] Figure 13 The structure of a MAC CE message for indicating a TCI status according to an embodiment of the present disclosure is shown;

[0037] Figure 14 An example of configuring a serving cell and a cell identifier per TRP according to an embodiment of the present disclosure is shown;

[0038] Figure 15 An example of a method of configuring and indicating TCI / QCL for inter-cell multi-TRP operation according to an embodiment of the present disclosure is shown;

[0039] Figure 16 Another example of a method of configuring and indicating TCI / QCL for inter-cell multi-TRP operation according to an embodiment of the present disclosure is shown;

[0040] Figure 17 shows intra-cell multi-TRP operation and inter-cell multi-TRP operation according to an embodiment of the present disclosure;

[0041] Figure 18 is a block diagram showing the structure of a UE according to an embodiment of the present disclosure; and

[0042] Figure 19 is a block diagram illustrating a structure of a base station according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0044] When describing the embodiments of the present disclosure, descriptions related to technical contents well known in the art and not directly related to the present disclosure will be omitted. Omission of unnecessary descriptions is to prevent the main idea of ​​the present disclosure from being obscured and to convey the main idea more clearly.

[0045] For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted or schematically shown. In addition, the size of each element does not fully reflect the actual size. In the accompanying drawings, the same or corresponding elements have the same reference numerals.

[0046] The advantages and features of the present disclosure and the manner in which they are achieved will become apparent by reference to the embodiments described in detail below in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following embodiments are provided only to fully disclose the present disclosure and to inform those skilled in the art of the scope of the present disclosure, and the present disclosure is limited only by the scope of the appended claims. Throughout the specification, the same or similar reference numerals represent the same or similar elements.

[0047] In this article, it will be understood that each box of the flowchart diagram and the combination of boxes in the flowchart diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a device for implementing the functions specified in one or more flowchart boxes. These computer program instructions can also be stored in a computer-usable or computer-readable memory that can instruct the computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-usable or computer-readable memory produce an article including an instruction device, which implements the functions specified in one or more flowchart boxes. The computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are performed on the computer or other programmable device, thereby generating a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flowchart boxes.

[0048] In addition, each block of the flowchart diagram may represent a module, segment, or code portion, which includes one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the blocks may not appear in the order in which they are performed. For example, depending on the functions involved, two blocks shown in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order.

[0049] As used herein, "unit" refers to a software component or a hardware component that performs a predetermined function, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, "unit" does not always have the meaning that is limited to software or hardware. "Unit" can be constructed to be stored in an addressable storage medium or to perform one or more processors. Therefore, "unit" includes, for example, software components, object-oriented software components, class components or task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays and parameters. The elements and functions provided by "unit" can be combined into smaller numbers of elements or "units", or divided into larger numbers of elements or "units". In addition, element and "unit" or can be implemented as reproducing one or more CPUs in equipment or secure multimedia cards. In addition, "unit" in the embodiment can include one or more processors.

[0050] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, when it is determined that a detailed description of a known function or configuration incorporated herein may make the subject matter of the present disclosure unnecessarily unclear, its description will be omitted. The terms to be described below are terms defined in consideration of the functions in the present disclosure and may differ according to the user, the user's intention or habit. Therefore, the definition of the terms should be based on the content of the entire specification. In the following description, a base station is an entity that allocates resources to a terminal and may be at least one of a gNode B, an eNode B, a Node B, a base station (BS), a wireless access unit, a base station controller, and a node on a network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. Of course, the examples of base stations and terminals are not limited thereto. The following description of the present disclosure is directed to a technology for receiving broadcast information from a base station by a terminal in a wireless communication system. The present disclosure relates to a communication technology and a system thereof for integrating IoT technology with a 5G (fifth generation) communication system designed to support higher data transmission rates than a 4G (fourth generation) system. The present disclosure can be applied to smart services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail commerce, safety and security-related services, etc.) based on 5G communication technology and IoT-related technologies.

[0051] In the following description, for the sake of convenience, 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 elements, etc. are illustratively used. Therefore, the present disclosure is not limited to the terms used below, and other terms referring to subjects with equivalent technical meanings may be used.

[0052] In the following description, for convenience of description, terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard may be used. However, the present disclosure is not limited to these terms and names and can be applied to systems conforming to other standards in the same manner.

[0053] Wireless communication systems are evolving from initially providing voice-oriented services to broadband wireless communication systems for providing high-speed and high-quality packet data services in accordance with communication standards such as High Speed ​​Packet Access (HSPA), Long Term Evolution (LTE or Evolved Universal Terrestrial Radio Access (E-UTRA)), LTE-Advanced (LTE-A) or LTE-Pro of 3GPP, High Speed ​​Packet Data (HRPD) or Ultra Mobile Broadband (UMB) of 3GPP2, and IEEE 802.16e.

[0054] As a representative example of a broadband wireless communication system, the LTE system adopts an orthogonal frequency division multiplexing (OFDM) scheme for the downlink (DL) and a single-carrier frequency division multiple access (SC-FDMA) scheme for the uplink (UL). The uplink refers to the radio link through which a user equipment (UE) or mobile station (MS) transmits data or control signals to an eNode B or base station (BS), while the downlink refers to the radio link through which an eNode B transmits data or control signals to a UE. These multiple access schemes allocate and manage the time-frequency resources used to carry data or control information for each user so that they do not overlap, that is, are orthogonal to each other, thereby dividing the data or control information for each user.

[0055] Post-LTE communication systems, namely 5G communication systems, need to be able to freely reflect the diverse needs of users and service providers, and therefore need to support services that meet these needs. Services considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC).

[0056] According to some embodiments, eMBB is intended to provide a data rate that is further increased than the data rate supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, for one base station, eMBB needs to be able to provide a peak data rate of 20Gbps in the downlink and a peak data rate of 10Gbps in the uplink. In addition, eMBB needs to provide an increased user-perceived data rate. In order to meet these requirements, improved transmission and reception technologies are needed, including enhanced multiple-input multiple-output (MIMO) transmission technology. In addition, the data rate required by the 5G communication system can be met by adopting a frequency bandwidth wider than 20MHz in a frequency band ranging from 3GHz to 6GHz or a frequency band of 6GHz or higher, instead of the 2GHz frequency band currently used for LTE.

[0057] In 5G communication systems, mMTC is considered to support application services such as the Internet of Things (IoT). In order to effectively provide IoT, mMTC may need to support access to a large number of UEs in a cell, enhanced UE coverage, increased battery time, reduced UE costs, etc. IoT is attached to various sensors and various devices to provide communication functions, so it is necessary to be able to support a large number of UEs in a cell (e.g., 1,000,000 UEs / km2). Due to the nature of the service, UEs supporting mMTC are likely to be located in shadow areas that are not covered by the cell, such as the basement of a building, and therefore may require wider coverage than other services provided by the 5G communication system. UEs supporting mMTC need to be configured as low-cost UEs and may require very long battery life because it is difficult to frequently replace the battery of the UE.

[0058] Finally, URLLC is a cellular-based mission-critical wireless communication service that is used for remote control of robots or machines, industrial automation, drones, remote healthcare, emergency alerts, etc., and needs to provide ultra-low latency and ultra-reliable communications. For example, services that support URLLC not only need to meet an air interface latency of less than 0.5 milliseconds, but also need to have a packet error rate of 10-5 or lower. Therefore, for services that support URLLC, the 5G system needs to provide a shorter transmission time interval (TTI) than other services, and also needs a design for allocating wide resources in the frequency band. The aforementioned mMTC, URLLC, and eMBB are merely examples of different service types, and the service types to which the present disclosure is applied are not limited to the aforementioned examples.

[0059] The aforementioned services considered in the 5G communication system need to be provided in an integrated manner based on a framework. That is, for efficient resource management and control, it is preferred to control and transmit the services as an integrated system rather than operating them independently.

[0060] Hereinafter, although the embodiments will be described with reference to LTE, LTE-A, LTE Pro, or NR systems as examples, these embodiments may also be applied to other communication systems having similar technical backgrounds or channel forms. In addition, without departing from the scope of the present disclosure as determined by those skilled in the art, the embodiments may also be applied to other communication systems through some modifications.

[0061] The present disclosure relates to a method and apparatus for transmitting data and control signals between a plurality of transmission nodes and a UE performing cooperative communication to improve communication reliability.

[0062] According to the present disclosure, when network cooperative communication is used in a wireless communication system, the UE can improve the reliability of data / control signals transmitted or received through repeated transmission between transmission points, or can increase the transmission capacity of data / control signals transmitted or received through separate (independent) transmission for each transmission point.

[0063] Hereinafter, the frame structure of the 5G system will be described in detail with reference to the accompanying drawings.

[0064] Figure 1 The transmission structure in the time-frequency domain in an LTE system, an LTE-A system, an NR system, or a similar wireless communication system is shown.

[0065] Figure 1 The basic structure of the time-frequency domain, which is a radio resource area for transmitting data or control channels in the 5G system, is shown.

[0066] exist Figure 1 In the time-frequency domain, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The basic unit of resources in the time-frequency domain is a resource element (RE) 1-01, which can be defined by an orthogonal frequency division multiplexing (OFDM) symbol 1-02 on the time axis and a subcarrier 1-03 on the frequency axis. In the frequency domain, (eg, 12) consecutive REs may form one resource block (RB) 1-04.

[0067] Figure 2 The structure of frames, subframes, and time slots in a 5G system is shown.

[0068] Figure 2 An example of the structure of a frame 2-00, a subframe 2-01, and a time slot 2-02 is shown. One frame 2-00 may be defined as 10 ms. One subframe 2-01 may be defined as 1 ms. Therefore, one frame 2-00 may include a total of ten subframes 2-01. One time slot 2-02 and 2-03 may be defined as 14 OFDM symbols (i.e., the number of symbols per time slot). One subframe 2-01 may include one or more time slots 2-02 and 2-03, and the number of time slots 2-02 and 2-03 per subframe 2-01 may vary according to the set subcarrier spacing values ​​μ2-04 and 2-05.

[0069] exist Figure 2 In the example, as the subcarrier spacing values ​​set, μ = 0 (2-04) and μ = 1 (2-05). When μ = 0 (2-04), one subframe 2-01 can include one time slot 2-02; when μ = 1 (2-05), one subframe 2-01 can include two time slots 2-03. That is, the number of time slots per subframe is The number of time slots per frame can be changed according to the subcarrier spacing value μ. Can be changed accordingly. Set μ according to each subcarrier spacing and It can be defined as in Table 1.

[0070] [Table 1]

[0071]

[0072] In NR, a component carrier (CC) or serving cell can include up to 250 RBs. Therefore, when a UE always receives the entire serving cell bandwidth as in LTE, the UE's power consumption can be extremely high. To address this issue, the base station can configure one or more bandwidth parts (BWPs) for the UE, allowing the UE to change the reception area within the cell.

[0073] In NR, the base station can configure the initial BWP for the UE through the Master Information Block (MIB), which is the bandwidth of CORESET#0 (or Common Search Space: CSS). Subsequently, the base station can configure the first BWP for the UE through RRC signaling and report at least one BWP configuration information, which can be indicated in the future through Downlink Control Information (DCI). The base station can report the BWPID through DCI to indicate the frequency band used by the UE. When the UE fails to receive DCI in the currently allocated BWP for a specified time or longer, the UE returns to the default BWP and attempts to receive DCI.

[0074] Figure 3 A configuration of a BWP in a wireless communication system according to an embodiment is shown.

[0075] refer to Figure 3, UE bandwidth 3-00 may include two BWPs, namely BWP#1 3-05 and BWP#2 3-10. The base station may configure one BWP or multiple BWPs for the UE and may configure information about each BWP as shown in Table 2 below.

[0076] [Table 2]

[0077]

[0078]

[0079] In addition to the multiple configured information shown in Table 2, various parameters related to the BWP can be configured for the UE. The aforementioned multiple information can be sent from the base station to the UE via higher-layer signaling (e.g., RRC signaling). One configured BWP or at least one of multiple configured BWPs can be activated. Whether to activate the configured BWP can be semi-statically indicated to the UE via RRC signaling or dynamically via a MAC control element (CE) or DCI.

[0080] The configuration of BWP supported by the 5G communication system can be used for various purposes.

[0081] In one example, when the bandwidth supported by the UE is less than the system bandwidth, the bandwidth supported by the UE can be supported by configuring the BWP. For example, the frequency position of the BWP in Table 2 (configuration information 2) can be set for the UE so that the UE can send and receive data at a specific frequency position within the system bandwidth.

[0082] In another example, a base station can configure multiple BWPs for a UE to support different parameter sets. For example, to support sending and receiving data using both a 15 kHz subcarrier spacing and a 30 kHz subcarrier spacing for a random UE, two BWPs can be configured to use a 15 kHz subcarrier spacing and a 30 kHz subcarrier spacing, respectively. Different BWPs can be frequency-division multiplexed (FDM). When a UE intends to send and receive data with a specific subcarrier spacing, it can activate the BWP configured with that subcarrier spacing.

[0083] In another example, the base station can configure a BWP with different bandwidths for the UE in order to reduce the UE's power consumption. For example, when the UE supports a very large bandwidth (e.g., a bandwidth of 100 MHz) and always sends and receives data in this bandwidth, the UE may consume a lot of power. Specifically, the UE unnecessarily monitors the downlink control channel on a large bandwidth of 100 MHz even when there is no traffic, which is very inefficient in terms of power consumption. Therefore, in order to reduce the UE's power consumption, the base station can configure a BWP with a relatively small bandwidth, such as a 20 MHz BWP, for the UE. The UE can perform monitoring operations in the 20 MHz BWP when there is no traffic, and when data is generated, the UE can use the 100 MHz bandwidth to send and receive data according to instructions from the base station.

[0084] Figure 4 A method for dynamically changing the configuration of a BWP according to an embodiment of the present disclosure is shown.

[0085] refer to Figure 4 As described in Table 2, the base station can configure one BWP or multiple BWPs for the UE, and can report information about the bandwidth of the BWP, the frequency position of the BWP, and the parameter set of the BWP to the UE as the configuration of each BWP. Figure 4 As shown, for one UE, which two BWPs are configured as BPW#1 4-05 and BWP#2 4-10 in the UE bandwidth 4-00. One or more configured BWPs may be activated, and Figure 4 An example of activating one BWP is shown. BWP #1 4-02 in the configured BWP is activated in time slot #0 4-25, and the UE can monitor the Physical Downlink Control Channel (PDCCH) in the control region 1 4-45 configured in BWP #1 4-05, and can transmit and receive data 4-55 in BWP #1 4-05. The control region in which the UE receives the PDCCH can vary depending on which BWP is activated in the configured BWP, and thus the bandwidth over which the UE monitors the PDCCH can vary.

[0086] The base station may also send an indicator to the UE for switching the configuration of the BWP. Here, switching the configuration of the BWP may be considered the same as activating a specific BWP (e.g., switching the activated BWP from BWP A to BWP B). The base station may send a configuration switching indicator to the UE in a specific time slot. After receiving the configuration switching indicator from the base station, the UE may determine the BWP to be activated by applying the changed configuration according to the configuration switching indicator from the specific time. In addition, the UE may monitor the PDCCH in the control region configured in the activated BWP.

[0087] exist Figure 4In the example, the base station may send a configuration switching indicator 4-15 to the UE in time slot #1 4-30, which indicates that the activated BWP is switched from the existing BWP #1 4-05 to BWP #2 4-10. After receiving the indicator, the UE may activate BWP #2 6-10 according to the content of the indicator. Here, a transition time 4-20 for BWP switching may be required, and the time to switch and apply the BWP to be activated may be determined accordingly. Figure 4 In the example, after receiving the configuration switching indicator 4-15, a transition time 4-20 of one time slot is required. Data transmission and reception may not be performed during the transition time 4-20 (4-60). Therefore, BWP #2 4-10 may be activated in time slot #2 4-35, so that control channels and data can be transmitted and received via this BWP.

[0088] The base station may pre-configure one or more BWPs for the UE via higher layer signaling (e.g., RRC signaling), and may indicate activation by mapping configuration switching indicators 4-15 to one of the BWP configurations pre-configured by the base station. For example, a log2N-bit indicator may indicate a BWP selected from N pre-configured BWPs. Table 3 shows an example of using a two-bit indicator to indicate configuration information about the BWP.

[0089] [Table 3]

[0090] Indicator value BWP configuration 00 Bandwidth configuration A configured via higher layer signaling 01 Bandwidth configuration B configured via higher layer signaling 10 Bandwidth configuration C configured via higher layer signaling 11 Bandwidth configuration D configured via higher layer signaling

[0091] The configuration switching indicators 4-15 for BWP shown in Table 4 may be transmitted from the base station to the UE via medium access control (MAC) control element (CE) signaling or L1 signaling (eg, common DCI, group common DCI, or UE-specific DCI).

[0092] The time to apply BWP activation according to the configuration switch indicator 4-15 for BWP shown in Table 4 above may depend on the following. The time to apply the configuration switch may depend on a predefined value (e.g., applying the configuration switch after N (≥1) time slots since receiving the configuration switch indicator), which may be set by the base station for the UE via higher layer signaling (e.g., RRC signaling) or may be sent via the configuration switch indicator 4-15. In addition, the time to apply the configuration switch may be determined by combining the above methods. After receiving the configuration switch indicator 4-15 for BWP, the UE may apply the switched configuration starting from the time obtained by the above method.

[0093] Figure 5 A control resource set (CORESET) for transmitting a downlink control channel in a 5G system according to an embodiment of the present disclosure is shown.

[0094] refer to Figure 5 In this embodiment, the UE BWP 5-10 may be configured on the frequency axis, and two control resource sets (control resource set #1 5-01 and control resource set #2 5-02) may be configured in one time slot 5-20 on the time axis. The control resource sets 5-01 and 5-02 may be configured in a specific frequency resource 5-03 in the entire UE BWP 5-10 on the frequency axis. The control resource sets 5-01 and 5-02 may be configured with one or more OFDM symbols on the time axis, which may be defined as a control region set duration 5-04. Figure 5 In the example of FIG, control resource set #1 5-01 is configured with a control resource set duration of two symbols, and control resource set #2 5-02 is configured with a control resource set duration of one symbol.

[0095] The control resource set in the above-mentioned 5G system can be configured for the UE by the base station through high-layer signaling (e.g., system information, master information block (MIB) or radio resource control (RRC) signaling). Configuring the control resource set for the UE means providing the UE with information such as the identity of the control resource set, the frequency location of the control resource set, and the symbol duration of the control resource set. For example, the information used to configure the control resource set for the UE may include the multiple pieces of information shown in Table 4.

[0096] [Table 4]

[0097]

[0098]

[0099] In Table 4, the tci-StatesPDCCH (abbreviated as TCI state) configuration information may include information about the index of one or more synchronization signal (SS) / physical broadcast channel (PBCH) blocks (referred to as SSB or SS / PBCH blocks) that have a quasi-co-location (QCL) relationship with the demodulation reference signal (DMRS) transmitted in the control resource set or the index of the channel state information reference signal (CSI-RS).

[0100] In a wireless communication system, one or more different antenna ports (which may be replaced by one or more channels, signals, and combinations thereof, but in the following description of the present disclosure, for convenience, the term "different antenna ports" is used throughout) can be associated with each other through the following QCL configuration.

[0101]

[0102] Specifically, the QCL configuration can associate two different antenna ports with a relationship between a (QCL) target antenna port and a (QCL) reference antenna port, and when receiving the target antenna port, the UE can apply (assume) all or some of the statistical characteristics of the channel measured at the reference antenna port (for example, large-scale parameters of the channel or the UE's receive spatial filter coefficients or transmit spatial filter coefficients, such as Doppler shift, Doppler spread, average delay, delay spread, average gain, and spatial Rx (or Tx) parameters). Here, the target antenna port refers to an antenna port that transmits a channel or signal configured by a high-layer configuration including the QCL configuration, or an antenna port that transmits a channel or signal to which a TCI state indicating the QCL configuration is applied. The reference antenna port refers to an antenna port that transmits a channel or signal indicated (specified) by the referenceSignal parameter in the QCL configuration.

[0103] Specifically, the statistical characteristics of a channel defined by a QCL configuration (indicated by the parameter qcl-Type in the QCL configuration) can be classified according to the following QCL type.

[0104] o 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

[0105] o 'QCL-TypeB': {Doppler shift, Doppler spread}

[0106] o 'QCL-TypeC': {Doppler shift, average delay}

[0107] o 'QCL-TypeD': {spatial Rx parameters}

[0108] The QCL type is not limited to the above four types, but in order not to confuse the main points of the description, not all possible combinations are listed. QCL-TypeA is a QCL type used when all statistical characteristics measurable on the frequency axis and time axis are available for reference because the bandwidth and transmission period of the target antenna port are sufficient compared to the reference antenna port (i.e., when the number of samples and transmission band / time of the target antenna port are larger than the number of samples and transmission band / time of the reference antenna port on both the frequency axis and the time axis). QCL-TypeB is a QCL type used when the bandwidth of the target antenna port is sufficient to measure statistical characteristics measurable on the frequency axis (i.e., Doppler shift and Doppler spread). QCL-TypeC is a QCL type used when the bandwidth and transmission period of the target antenna port are insufficient to measure second-order statistics (i.e., Doppler spread and delay spread), so only first-order statistics (i.e., Doppler shift and average delay) are available for reference. QCL-TypeD is a QCL type configured in the following case: the spatial Rx filter value used when receiving the reference antenna port can be used when receiving the target antenna port.

[0109] The base station can configure one target antenna port configuration or indicate up to two QCL configurations through the following TCI states.

[0110]

[0111] Of the two QCL configurations included in one TCI state configuration, the first QCL configuration can be configured as one of QCL-Type A, QCL-Type B, and QCL-Type C. The configurable QCL type is specified based on the type of the target antenna port and the reference antenna port, which will be described in detail below. Of the two QCL configurations included in one TCI state configuration, the second QCL configuration can be configured as QCL-Type D, and in some cases, can be omitted.

[0112] Tables 4-1 to 4-5 show valid TCI state configurations according to target antenna port types.

[0113] Table 4-1 shows the valid TCI state configurations when the target antenna port is a CSI-RS (or Tracking Reference Signal: TRS) for tracking. TRS refers to an NZP CSI-RS with no repetition parameter configured and trs-Info set to true. In Table 4-1, configuration 3 can be used for aperiodic TRS.

[0114] Valid TCI state configuration when the target antenna port is CSI-RS (TRS) for tracking

[0115]

[0116] Table 4-2 shows the valid TCI state configuration when the target antenna port is a CSI-RS for CSI. A CSI-RS for CSI refers to an NZP CSI-RS for which no repetition parameter is configured and trs-Info is not set to true.

[0117] Valid TCI state configuration when the target antenna port is CSI-RS (TRS) for tracking

[0118]

[0119] Table 4-3 shows the valid TCI state configuration when the target antenna port is the CSI-RS for beam management (BM, equivalent to the CSI-RS used for L1 RSRP reporting). The CSI-RS for BM refers to the NZP CSI-RS in which the repetition parameter is configured as on or off and trs-Info is not configured as true.

[0120] Valid TCI state configuration when the target antenna port is CSI-RS for BM (for L1 RSRP reporting)

[0121]

[0122] Table 4-4 shows the valid TCI state configuration when the target antenna port is PDCCH DMRS. Valid TCI state configuration when the target antenna port is PDCCH DMRS

[0123]

[0124] Table 4-5 shows the valid TCI state configuration when the target antenna port is PDSCH DMRS. Valid TCI state configuration when the target antenna port is PDSCH DMRS

[0125]

[0126] The representative QCL configuration methods shown in Tables 4-1 to 4-5 configure the target and reference antenna ports as "SSB" → "TRS" → "CSI-RS for CSI, CSI-RS for BM, PDCCH DMRS, or PDSCH DMRS" at each stage, and perform operations accordingly. This allows statistical characteristics measurable from the SSB and TRS to be linked to each antenna port, facilitating reception operations in the terminal.

[0127] Hereinafter, a method of allocating time and frequency resources for data transmission in an NR system will be described.

[0128] In addition to the frequency domain resource candidate allocation indicated by the BWP, the NR system can also provide the following specific frequency domain resource allocation (FD-RA).

[0129] Figure 6 A PDSCH frequency domain resource allocation method in an NR system according to an embodiment of the present disclosure is shown.

[0130] refer to Figure 6 In the NR system, as a frequency domain resource allocation method, it can include type 06-00, type 16-05 and dynamic switching 6-10 that can be configured by a high layer.

[0131] When the UE is configured to use only resource type 0 (6-00) through higher-layer signaling, some downlink control information (DCI) used to allocate PDSCH to the UE has a bitmap with an NRBG bit, the conditions of which will be described later. Here, NRBG indicates the number of resource block groups (RBGs) determined as shown in Table 5 based on the BWP size assigned by the BWP indicator and the higher-layer parameter rbg-Size, and the RBG phase indicated by 1 in the bitmap, and data is transmitted on the RBG indicated by 1 according to the bitmap.

[0132] [Table 5]

[0133] Bandwidth portion size Configuration 1 Configuration 2 1-36 2 4 37-72 4 8 73-144 8 16 145-275 16 16

[0134] When the UE is configured to use only resource type 16-05 through higher layer signaling, some DCIs used to allocate PDSCH to the UE have The frequency domain resource allocation information of the bit is described later. The conditions of the information will be described later. Through this information, the base station can configure the starting VRB 6-20 and the length 6-25 of the frequency domain resources continuously allocated therefrom.

[0135] When the UE is configured to use both resource type 0 and resource type 1 (6-10) through higher layer signaling, some DCI used to allocate PDSCH to the UE has frequency domain resource allocation information with a payload of 6-15 for configuring resource type 0 and a larger value of 6-35 bits among payloads 6-20 and 6-25 for configuring resource type 1, the conditions of which will be described later. Here, one bit can be added to the most significant bit (MSB) of the frequency domain resource allocation information in the DCI, where a bit equal to 0 can indicate the use of resource type 0, and a bit equal to 1 can indicate the use of resource type 1.

[0136] Figure 7A method for allocating time-domain resources of a physical downlink shared channel (PDSCH) in a wireless communication system according to an embodiment of the present disclosure is shown.

[0137] refer to Figure 7 The base station can configure the subcarrier spacing (μ PDSCH ,μ PDCCH ), the scheduling offset (K0) value and the starting position 7-00 and length 7-05 of the OFDM symbol in the time slot dynamically indicated by the DCI to indicate the time domain position of the PDSCH resource.

[0138] Figure 8 A time domain resource allocation method according to an embodiment of the present disclosure according to the subcarrier spacing of a data channel and the subcarrier spacing of a control channel in a wireless communication system is shown.

[0139] Reference Figure 8 , when the data channel and the control channel have the same subcarrier spacing (8-00, μ PDSCH =μ PDCCH ), since the data slot number and the control slot number are the same, the base station and the UE recognize that the scheduling offset occurs according to the predetermined slot offset K0.

[0140] When the subcarrier spacing of the data channel is different from the subcarrier spacing of the control channel (8-05, μ PDSCH ≠μ PDCCH ), since the data time slot number and the control time slot number are different, the base station and the UE recognize that the scheduling offset is based on the subcarrier spacing of the PDCCH and occurs according to the predetermined time slot offset K0.

[0141] In the NR system, for efficient control channel reception of the UE, various types of DCI formats as shown in Table 6 are provided according to the purpose.

[0142] [Table 6]

[0143]

[0144] For example, the base station may use DCI format 0_0 or DCI format 0_1 ​​to schedule a PDSCH for one cell.

[0145] When transmitted together with a CRC scrambled with a cell radio network temporary identifier (C-RNTI), a configured scheduling RNTI (CS-RNTI), or a new RNTI, DCI format 0_1 ​​includes at least the following pieces of information.

[0146] - DCI format identifier (1 bit): DCI format indicator, always set to 1.

[0147] - Frequency domain resource allocation (NRBG Bit OR bit): indicates frequency domain resource allocation. When DCI format 1_0 is monitored in the UE-specific search space, is the size of the active DL BWP; otherwise, is the size of the initial DL BWP. N RBG The detailed method is described in the above frequency domain resource allocation.

[0148] - Time domain resource allocation (0 to 4 bits): indicates the time domain resource allocation according to the aforementioned description.

[0149] - VRB to PRB mapping (1 bit): 0 indicates non-interleaved VRP to PRB mapping, 1 indicates interleaved VRP to PRB mapping.

[0150] - Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0151] - New data indicator (1 bit): indicates whether the PDSCH corresponds to initial transmission or retransmission according to toggling.

[0152] - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission.

[0153] -HARQ process number (4 bits): indicates the HARQ process number used for PDSCH transmission.

[0154] - Downlink Assignment Index (DAI) (2 bits): DAI indicator.

[0155] - TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator.

[0156] -PUCCH resource indicator (3 bits): PUCCH resource indicator, indicating one of eight resources configured by higher layers.

[0157] -PDSCH-to-HARQ_feedback timing indicator (3 bits): HARQ feedback timing indicator, indicating one of eight feedback timing offsets configured by higher layers.

[0158] When transmitted together with a CRC scrambled with a cell radio network temporary identifier (C-RNTI), a configured scheduling RNTI (CS-RNTI), or a new RNTI, DCI format 1_1 includes at least the following information.

[0159] - DCI format identifier (1 bit): DCI format indicator, always set to 1.

[0160] - Carrier indicator (0 or 3 bits): Indicates the CC (or cell) that transmits the PDSCH allocated by the DCI.

[0161] - Bandwidth part indicator (0, 1, or 2 bits): indicates the BWP in which the PDSCH allocated by the DCI is transmitted.

[0162] - Frequency domain resource allocation (payload is determined according to the aforementioned frequency domain resource allocation): indicates frequency domain resource allocation. is the size of the active DL BWP. The detailed method is described in the above frequency domain resource allocation.

[0163] - Time domain resource allocation (0 to 4 bits): indicates the time domain resource allocation according to the aforementioned description.

[0164] - VRB to PRB mapping (0 or 1 bit): 0 indicates non-interleaved VRB to PRB mapping, 1 indicates interleaved VRB to PRB mapping. When frequency domain resource allocation is set to resource type 0, this information is 0 bit.

[0165] -PRB bundling size indicator (0 or 1 bit): When the higher-layer parameter prb-BundlingType is not set or is set to "static", this information is 0 bit; when the higher-layer parameter prb-BundlingType is set to "dynamic", this information is 1 bit.

[0166] - Rate matching indicator (0, 1, or 2 bits): indicates the rate matching mode.

[0167] - ZP CSI-RS trigger (0, 1, or 2 bits): an indicator that triggers aperiodic ZP CSI-RS.

[0168] For transport block 1:

[0169] - Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0170] - New data indicator (1 bit): indicates whether the PDSCH corresponds to initial transmission or retransmission according to toggling.

[0171] - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission.

[0172] -For transport block 2:

[0173] - Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0174] - New data indicator (1 bit): indicates whether the PDSCH corresponds to initial transmission or retransmission according to toggling.

[0175] - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission.

[0176] -HARQ process number (4 bits): indicates the HARQ process number used for PDSCH transmission.

[0177] - Downlink Assignment Index (0, 2, or 4 bits): DAI indicator.

[0178] - TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator.

[0179] -PUCCH resource indicator (3 bits): PUCCH resource indicator, indicating one of eight resources configured by higher layers.

[0180] -PDSCH-to-HARQ_feedback timing indicator (3 bits): HARQ feedback timing indicator, indicating one of eight feedback timing offsets configured by higher layers.

[0181] - Antenna port (4, 5, or 6 bits): indicates a DMRS port and a CDM group without data.

[0182] -Transmission Configuration Indication (0 or 3 bits): TCI indicator.

[0183] - SRS request (2 or 3 bits): SRS transmission request indicator.

[0184] -CBG transmission information (0, 2, 4, 6, or 8 bits): an indicator indicating whether the code block group in the allocated PDSCH is transmitted. 0 indicates that the CBG is not transmitted, and 1 indicates that the CBG is transmitted.

[0185] -CBG flush information (0 or 1 bit): Indicator indicating whether the previous CBG is contaminated. 0 indicates that the CBG may be contaminated, and 1 indicates that the CBG can be combined in retransmission reception.

[0186] -DMRS sequence initialization (0 or 1 bit): DMRS scrambling ID selection indicator.

[0187] The number of DCIs of different sizes that a UE can receive per slot in a cell is up to 4. The number of DCIs of different sizes scrambled with a C-RNTI that a UE can receive per slot in a cell is up to 3.

[0188] Antenna port indication can be indicated by Table 7 to Table 10.

[0189] [Table 7] Antenna port (1000+DMRS port), dmrs-Type=1, maxLength=1

[0190]

[0191] [Table 8] Antenna port (1000+DMRS port), dmrs-Type=1, maxLength=2

[0192]

[0193] [Table 9] Antenna port (1000+DMRS port), dmrs-Type=2, maxLength=1

[0194]

[0195] [Table 10] Antenna port (1000+DMRS port), dmrs-Type=2, maxLength=2

[0196]

[0197] The DMRS ports used are indicated using Table 7 when dmrs-type is 1 and maxLength is 1; Table 8 when dmrs-Type=1 and maxLength=2; Table 9 when dmrs-type=2 and maxLength=1; and Table 10 when drms-tpye is 2 and maxLength is 2. In the table, the numbers 1, 2, and 3 indicated by the number of DMRS CDM groups without data refer to CDMRS groups {0}, {0, 1}, and {0, 1, 2}, respectively. The DMRS ports are arranged in sequence according to the index of the port used. The antenna port is indicated by DMRS port + 1000. As shown in Tables 11 and 12, the CDM group of DMRS is associated with the method for generating DMRS sequence and antenna port. Table 11 shows the parameters when dmrs-type=1 is used, and Table 12 shows the parameters when dmrs-type=2 is used.

[0198] [Table 11] Parameters for PDSCH DM-RS dmrs-type = 1

[0199]

[0200] [Table 12] Parameters for PDSCH DM-RS dmrs-type = 2

[0201]

[0202] The DMRS sequence according to the parameters can be determined by Equation 1.

[0203]

[0204] When only one codeword is enabled in Tables 7 and 8, rows 2, 9, 10, 11, and 30 can be used only for single-user MIMO. That is, the UE cannot assume that different UEs are co-scheduled and cannot perform multi-user MIMO reception operations such as multi-user interference cancellation, nulling, or whitening operations.

[0205] When only one codeword is enabled in Tables 9 and 10, rows 2, 10, and 23 may be used only for single-user MIMO. That is, the UE may not perform multi-user MIMO reception operations such as multi-user interference cancellation, nulling, or whitening, without assuming that different UEs are co-scheduled.

[0206] Figure 9 The wireless protocol structure of the base station and the UE when performing single cell, carrier aggregation (CA), and dual connectivity (DC) according to an embodiment of the present disclosure is shown.

[0207] refer to Figure 9 The wireless protocols of the NR system may include NR Service Data Adaptation Protocol (SDAP) 9-25 and 9-70, NR Packet Data Convergence Protocol (PDCP) 9-30 and 9-65, NR Radio Link Control (RLC) 9-35 and 9-60, and NR Medium Access Control (MAC) 9-40 and 9-55, which are located at the UE and NR base station respectively.

[0208] The main functions of NR SDAP 9-25 and 9-70 may include at least some of the following functions.

[0209] -Transmission of user plane data

[0210] - Mapping between QoS flows and DRBs for both DL and UL

[0211] - Marking QoS Flow ID in both DL and UL packets

[0212] -Reflective QoS flow to DRB mapping for UL SDAP PDU

[0213] Regarding the SDAP layer device, the UE can receive configuration regarding whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device for each PDCP layer device, each bearer or each logical channel via an RRC message. When the SDAP header is configured, the base station can use the one-bit NAS QoS reflection indicator (NAS reflection QoS) and the one-bit AS QoS reflection indicator (AS reflection QoS) of the SDAP header to indicate the mapping information that enables the UE to update or reconfigure the uplink and downlink QoS flows and data bearers. The SDAP header may include QoS flow ID information indicating QoS. QoS information can be used as data processing priority, scheduling information, etc. to support the desired service.

[0214] The main functions of NR PDCP 9-30 and 9-65 may include at least some of the following functions.

[0215] - Header compression and decompression (ROHC only)

[0216] -Transmission of user data

[0217] - Sequential delivery of higher-level PDUs

[0218] - Out-of-order delivery of higher-level PDUs

[0219] - Reordering of received PDCP PDUs

[0220] -Duplicate detection of lower layer SDUs

[0221] -Retransmission of PDCP SDU

[0222] -Encryption and decryption

[0223] - Timer-based SDU discard in uplink.

[0224] Among the above functions, the reordering function of the NR PDCP device refers to a function of rearranging the PDCP PDUs received in the lower layer in sequence based on the PDCP sequence number (SN). The reordering function may include a function of sending data to the upper layer in the rearranged order, or a function of sending data immediately regardless of the order. In addition, the reordering function may include a function of recording lost PDCP PDUs through reordering, a function of reporting the status of lost PDCP PDUs to the transmitter, and a function of requesting retransmission of lost PDCP PDUs.

[0225] The main functions of NR RLC 9-35 and 9-60 may include at least some of the following functions.

[0226] -Transmission of higher-level PDUs

[0227] - Sequential delivery of higher-level PDUs

[0228] - Out-of-order delivery of higher-level PDUs

[0229] - Error correction through ARQ

[0230] - RLC SDU splicing, segmentation and reassembly

[0231] - Re-segmentation of RLC data PDUs

[0232] -Reordering of RLC data PDUs

[0233] -Duplicate detection

[0234] -Protocol error detection

[0235] -RLC SDU discarded

[0236] -RLC reconstruction

[0237] Among the above functions, the in-sequence delivery function of the NR RLC device refers to a function of delivering RLC SDUs received from a lower layer to a higher layer in sequence. The in-sequence delivery function may include a function of reassembling and delivering multiple RLC SDUs when one original RLC SDU is divided into multiple RLC SDUs to be received. In addition, the in-sequence delivery function may include a function of rearranging received RLC PDUs based on the RLC SN or PDCP SN, and may include a function of recording lost RLC PDUs through reordering. In addition, the in-sequence delivery function may include a function of reporting the status of lost RLC PDUs to the transmitter, may include a function of requesting retransmission of lost RLC PDUs, and if there are lost RLC SDUs, may include a function of delivering only the RLC SDUs preceding the lost RLC SDU to the higher layer in sequence. In addition, the in-sequence delivery function may include a function of delivering all RLC SDUs received before the timer is started to the higher layer in sequence despite the presence of lost RLC SDUs when the timer expires, or may include a function of delivering all RLC SDUs received so far to the higher layer in sequence when the timer expires despite the presence of lost RLC SDUs. In addition, according to the in-sequence delivery function, the NR RLC device can process the RLC PDU in the order of reception (the order of arrival, regardless of the order of SN), and can deliver the RLC PDU to the PDCP device in an unordered manner. When a segment is received, the in-sequence delivery function enables the NR RLC device to receive the segment stored in the buffer or to be received later, reconstruct the segment into a complete RLC PDU, and deliver the RLC PDU to the PDCP device. The NR RLC layer may not include a splicing function, and the splicing function may be performed in the NR MAC layer, or may be replaced by a multiplexing function of the NR MAC layer.

[0238] The out-of-order delivery function of the NR RLC device refers to the function of delivering RLC SDUs received from the lower layer directly to the upper layer without considering the order, and may include the function of reassembling and delivering multiple RLC SDUs when an original RLC SDU is divided into multiple RLC SDUs to be received. In addition, the out-of-order delivery function may include the function of recording lost RLC PDUs by storing and reordering the RLC SN or PDCP SN of the received RLC PDUs.

[0239] NR MAC 9-40 and 9-55 can be connected to multiple NR RLC layer devices configured in one device, and the main functions of NR MAC can include at least some of the following functions.

[0240] - Mapping between logical channels and transport channels

[0241] -Multiplexing / demultiplexing of MAC SDU

[0242] -Dispatch information report

[0243] - Error correction through HARQ

[0244] - Priority handling between logical channels of a UE

[0245] - Priority handling between UEs through dynamic scheduling

[0246] -MBMS service identifier

[0247] -Transmission format selection

[0248] -filling

[0249] The NR PHY layers 9-45 and 9-50 may perform channel coding and modulation of high-layer data and convert the data into OFDM symbols to transmit the OFDM symbols via a wireless channel, or demodulate OFDM symbols received via a wireless channel and perform channel decoding of the OFDM symbols to deliver the OFDM symbols to a high layer.

[0250] The details of the wireless protocol structure may vary depending on the carrier (or cell) operation method. For example, when the base station sends data to the UE based on a single carrier (or cell), the base station and the UE use a protocol structure in which each layer has a single structure, as shown in 9-00. When the base station sends data to the UE based on carrier aggregation (CA) using multiple carriers in a single TRP, the base station and the UE use a protocol structure in which up to the RLC has a single structure, but the PHY layer is multiplexed through the MAC layer, as shown in 9-10. In another example, when the base station sends data to the UE based on dual connectivity (DC) using multiple carriers in multiple TRPs, the base station and the UE use a protocol structure in which up to the RLC has a single structure, but the PHY layer is multiplexed through the MAC layer, as shown in 9-20.

[0251] In LTE and NR, a UE has a procedure for reporting supported capabilities to a serving base station while connected to the base station. This procedure is referred to as UE capability reporting in the following description. The base station can send a UE capability query message to a connected UE requesting a capability report. This message can include a UE capability request for each RAT type. The request for each RAT type can include requested frequency band information.

[0252] In addition, the UE capability query message can request multiple RAT types in one RRC message container. According to another example, the UE capability query message including a request for each RAT type can be sent to the UE multiple times. That is, the UE capability query is repeated multiple times, and the UE can configure a UE capability information message in response to the query and can report the message multiple times. In the NR system, the UE capability for MR-DC including NR, LTE and EN-DC is requested. Typically, the UE capability query message is initially sent after the UE is connected, but when necessary, the base station can request a capability report from the UE in any case.

[0253] When receiving a UE capability report request from a base station, the UE can configure the UE capability according to the RAT type and frequency band information requested from the base station. The following describes a method for the UE to configure the UE capability in the NR system.

[0254] 1. When a list of LTE and / or NR frequency bands is provided to the UE via a UE capability request from the base station, the UE can configure a frequency band combination (BC) for EN-DC and NR standalone (SA). That is, the UE can configure a BC candidate list for EN-DC and NR SA based on the frequency bands requested from the base station via FreqBandList. The frequency bands can have priorities in the order described in FreqBandList.

[0255] 2. When the base station requests UE capability reporting by setting the "eutra-nr-only" flag or the "eutra" flag, the UE can completely remove NR SA BC from the configured BC candidate list. This operation can only occur when the LTE base station (eNB) requests the "eutra" capability.

[0256] 3. The UE removes the fallback BC from the candidate BC list configured in the above operation. The fallback BC corresponds to the superset BC from which the frequency band corresponding to at least one SCell has been removed and can be omitted because the superset BC may already cover the fallback BC. This operation also applies to MR-DC, i.e., LTE frequency bands. The BCs remaining after this operation form the final "candidate BC list."

[0257] 4. The UE can select the BC to be reported by selecting the BC corresponding to the requested RAT type from the final "candidate BC list". In this operation, the UE configures the supportedBandCombinationList in a predetermined order. That is, the UE can configure the BC to be reported and the UE capabilities according to the preset rat-Type order (nr->eutra-nr->eutra). In addition, the UE configures featureSetCombination for the configured supportedBandCombinationList, and configures a list of "candidate feature set combinations" based on the candidate BC list with the list of fallback BCs (including capabilities of the same or lower level) removed. The "candidate feature set combinations" include feature set combinations for both NR and EUTRA-NR BCs, and can be obtained from the feature set combinations of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0258] 5. When the requested RAT type is eutra-nr and is influential, featureSetCombinations is included in both the UE-MRDC-Capabilities and UE-NR-Capabilities containers. However, NR feature sets are only included in UE-NR-Capabilities.

[0259] After the UE capabilities are configured, the UE sends a UE capability information message including the UE capabilities to the base station. The base station can perform scheduling and transmission / reception management suitable for the UE based on the UE capabilities received from the UE.

[0260] Figure 10 A cooperative communication antenna port configuration according to an embodiment is shown.

[0261] Figure 10 An example of radio resource allocation per transmit-receive point (TRP) according to a joint transmission (JT) technique and scenario is shown. Figure 10 10-00 shows coherent joint transmission (C-JT) that supports coherent precoding between various cells, TRPs and / or beams. In C-JT, TRP A 10-05 and TRP B 10-10 transmit the same data (PDSCH), and multiple TRPs can perform joint precoding, which may mean that TRP A 10-05 and TRP B 10-10 transmit the same DMRS port for receiving the same PDSCH (for example, both TRPs transmit DMRS ports A and B). In this case, UE 10-15 can receive a DCI for receiving one PDSCH demodulated by DMRS ports A and B.

[0262] exist Figure 10 10-20 shows non-coherent joint transmission (NC-JT) that supports non-coherent precoding between various cells, TRPs and / or beams. In NC-JT, each cell, TRP and / or beam transmits a different PDSCH, so each precoding can be applied to each data (or PDSCH), which can mean that TRP A 10-25 and TRP B 10-30 transmit different DMRS ports for receiving different PDSCHs (for example, TRP A transmits DMRS port A, TRP B transmits DMRS port B). In this case, the UE receives two types of DCI for receiving PDSCH A demodulated by DMRS port A and PDSCH B demodulated by DMRS port B.

[0263] In order to support NC-JT in which two or more transmission points provide data to one UE at the same time, it is necessary to allocate PDSCHs sent from two (or more) different transmission points through a single PDCCH, or to allocate PDSCHs sent from two or more different transmission points through multiple PDCCHs. The UE can obtain the quasi-co-location (QCL) relationship between reference signals or channels based on L1 / L2 / L3 signaling, and can efficiently estimate the large-scale parameters of the reference signal or channel through the QCL relationship. When the transmission points of a reference signal or channel are different, the large-scale parameters are difficult to share, so the base station needs to simultaneously notify the UE of multiple quasi-co-location information about two or more transmission points through two or more TCI states when performing collaborative transmission.

[0264] When non-coherent coordinated transmission is supported by multiple PDCCHs, that is, when two or more PDCCHs simultaneously allocate two or more PDSCHs to the same serving cell and the same BWP, two or more TCI states can be allocated to the corresponding PDSCH or DMRS port through the corresponding PDCCH. However, when non-coherent coordinated transmission is supported by a single PDCCH, that is, when one PDCCH simultaneously allocates two or more PDSCHs to the same serving cell and the same BWP, two or more TCI states can be allocated to the corresponding PDSCH or DMRS port through a single PDCCH.

[0265] Assuming that the DMRS ports allocated to the UE at a specific time are divided into DMRS port group A transmitted from transmission point A and DMRS port group B transmitted from transmission point B, two or more TCI states are associated with the corresponding DMRS port groups, and the channel can be estimated based on different QCL assumptions for the corresponding groups. Different DMRS ports can be subjected to code division multiplexing (CDM), frequency division multiplexing (FDM) or time domain multiplexing (TDM) to increase channel measurement accuracy and reduce transmission load. Here, when the DMRS ports subjected to CDM are collectively referred to as CDM groups, since code-based multiplexing operates properly when the DMRS ports in the CDM group have similar channel characteristics (i.e., when the ports have similar channel characteristics, the ports are easily distinguished by orthogonal cover codes (OCC)), it can be important to ensure that the DMRS ports in the same CDM group do not have different TCI states.

[0266] Hereinafter, for convenience of description, Tables X to Y are referred to as "first antenna port indication (or legacy antenna port indication)", and tables in which some or all of the code points in Tables X to Y are modified are referred to as "second antenna port indication (new antenna port indication)". In addition, DMRS port and CDM group allocation are referred to as DMRS allocation.

[0267] The UE can determine the number of antenna ports used for PDSCH transmission by indicating the table of DMRS ports. In DCI format 1_1, the antenna port indication method based on Rel-15 is determined based on an index of 4 to 6 bits in length indicated by the antenna port field in the DCI. The UE can identify information about the number and index of DMRS ports used for PDSCH, the number of preamble symbols, and the number of CDM groups based on the indicator (index) sent by the base station. In addition, the UE can determine the dynamic change of the beamforming direction based on the information in the transmission configuration indication (TCI) field in DCI1_1. When tci-PresentDCI is configured as "enabled" in the higher layer, the UE can identify the TCI field of three bits of information to determine the TCI status activated for the DL BWP or scheduled component carrier and the direction of the beam associated with the DL-RS. When tci-PresentDCI is disabled, the UE can assume that the direction of the beam in beamforming has not changed.

[0268] In various embodiments of the present disclosure, a scenario in which PDSCHs transmitted from two (or more) different transmission points are allocated through multiple PDCCHs or a single PDCCH is considered. Rel-15 UEs can receive single-layer or multi-layer PDSCH streams that comply with QCL based on the TCI information and antenna port information in a single PDCCH. However, Rel-16 UEs can receive data in C-JT / NC-JT format transmitted from multiple TRPs or multiple base stations. In order to support C-JT / NC-JT, Rel-16 UEs require basic high-level configuration. Specifically, the UE can receive parameters or setting values ​​related to C-JT / NC-JT through high layers, and can perform configuration to support C-JT / NC-JT based on the received parameters or setting values.

[0269] The UE can support C-JT / NC-JT formatted data sent from multiple TRPs or multiple base stations. A UE that supports C-JT / NC-JT can receive parameters or setting values ​​related to C-JT / NC-JT in a high-level configuration, and can set the RRC parameters of the UE based on the parameters or setting values. For high-level configuration, the UE can utilize the UE capability parameter tci-StatePDSCH. The UE capability parameter tci-StatePDSCH defines the TCI states used for PDSCH transmission, and the number of TCI states can be configured to 4, 8, 16, 32, 64 and 128 in FR1, and to 64 and 128 in FR2. Of the configured number, up to eight states can be configured, and the eight states can be indicated by three bits of the TCI field of the DCI through a MAC CE message. The maximum value of 128 refers to the value indicated by the maxNumberConfiguredTCIstatesPerCC in the tci-StatePDSCH parameter included in the UE's capability signaling. This series of configuration processing from high-layer configuration to MAC CE configuration can be applied to beamforming indication or beamforming change command for at least one PDSCH in a TRP.

[0270] According to an embodiment of the present disclosure, a base station may instruct a UE to activate / deactivate a specific TCI state through at least one MAC CE signaling. Specifically, as in DCI format 1_1, when allocating a PDSCH for a specific UE, the base station enables the UE to dynamically support (receive) a QCL change command including (receiving) a beamforming direction indication or beamforming direction information using the TCI field.

[0271] The QCL change command refers to the operation applied when a UE that recognizes the TCI status field information in DCI format 1_1 receives PDSCH in the downlink after a certain time (for example, after a specified threshold (such as timeDurationForQCL) indicated by the UE capability report or signaling from the time of receiving the DCI), and the direction refers to the corresponding beamforming configuration direction related to the DL RS of the base station / TRP that obeys QCL.

[0272] The Rel-16 MAC CE may be configured in the form of a partially extended Rel-15 MAC CE message. This embodiment may propose to include all TCI states activated by the Rel-15 MAC CE in the TCI states activated by the Rel-16 MAC CE.

[0273] In one example, if Figure 11 As shown, the base station can determine a total of M TCI states of the TCI states 11-00 configured by the Rel-15 RRC, such as TCI#0, TCI#1, TCI#2, ..., TCI#M-1, and can select TCI#0', TCI#1', TCI#2', ..., TCI#K-1 as a subset of TCI states 11-20 selected by the Rel-15 MAC CE. However, a base station and a UE supporting Rel-16 can separately configure the TCI states configured by the RRC that support Rel-16, or can use the TCI states configured by the RRC in Rel-15 as is. Here, the TCI states configured by the RRC that support Rel-16 can include some or all of the TCI states configured by the RRC in Rel-15. When M=128, the number of TCI states of Rel-16 can be equal to or greater than 128. When a base station or UE expands the number of TCI states supported by Rel-15 in proportion to the number of base stations / TRPs operating according to C-JT / NC-JT in Rel-16, up to 256 TCI states can be configured if two TRPs operate. Here, in the TCI states configured by the RRC for Rel-16, the Rel-16 MAC CE may include some or all of the TCI states supported by the Rel-15 MAC CE. Specifically, when the Rel-16 MAC CE includes all TCI states supported by the Rel-15 MAC CE and the number of TCI states is expanded in proportion to the number of base stations / TRPs operating according to C-JT / NC-JT in Rel-16, up to 2K TCI states can be configured if two TRPs operate.

[0274] Table 13 shows the details of the tci-StatePDSCH parameters described in the above embodiment. Specifically, the FR2 mandatory value of the parameter maxNumberConfiguredTCIstatesPerCC can be modified from 64 to 128 or 256, or can be added separately as 64, 128 or 256 for C-JT / NC-JT.

[0275] [Table 13]

[0276]

[0277] In another example, a base station or UE supporting Rel-15 and Rel-16 may configure a maximum value for each of Rel-15 and Rel-16 to configure TCI states via a MAC CE, and may configure the number of TCI states to a value less than or equal to the configured maximum value. Various embodiments may be proposed below as methods for configuring the number of TCI states to a value less than or equal to the maximum value.

[0278] The number of TCI states activated by Rel-15 and Rel-16 MAC CE messages may be configured based on the UE capability value reported by the UE. According to another example, the number of TCI states activated by Rel-15 and Rel-16 MAC CE messages may be determined as a value preset by the base station. According to yet another example, the number of TCI states activated by Rel-15 and Rel-16 MAC CE messages may be determined as a value pre-agreed between the base station and the UE.

[0279] For example, Figure 11 As shown, the base station and UE can determine a total of M TCI states 11-00 configured by the Rel-15 RRC, such as TCI#0, TCI#1, TCI#2, ..., TCI#M-1, and select a subset 11-20 of the TCI states selected by the Rel-15 MAC CE, thereby arranging TCI#0', TCI#1', TCI#2', ..., TCI#K-1. When TCI#0 is selected from the M TCI states, TCI#0 can be arranged in TCI#0'. Here, for example, the maximum value K for base stations and UEs supporting Rel-15 can be configured or determined to be 8, and the maximum value K for base stations and UEs supporting Rel-16 can also be configured to be 8. When the maximum value is configured to 8, the base station can instruct the UE to select a beam for the PDSCH in a core set through a DCI-based beam selection operation. Beam selection can be determined by identifying TCI field information 11-40 in up to eight pieces of DCI. Figure 11The TCI field #I indicated in the DCI may be selected as a value from 0 to 7. For example, when the TCI field of the DCI is indicated as 000, it may be determined that TCI #0' (TCI #I = TCI #0') is indicated among TCI #0', TCI #1', TCI #2', TCI #3', TCI #4', TCI #5', TCI #6', and TCI #7'. Although this embodiment shows that each maximum value is configured as 8 (K = 8), the maximum value may be configured as a value less than 8. Although this embodiment shows that the maximum value K of the MAC CE for Rel-15 and the maximum value K of the MAC CE for Rel-16 are the same, the maximum values ​​may be configured as different values.

[0280] In another example, when the number of TCI states scales proportionally with the number of base stations / TRPs operating in C-JT / NC-JT, if two TRPs operate, the maximum value of K for base stations and UEs supporting Rel-16 can be configured as 16. When the maximum value is configured as 16, the base station can instruct the UE to select one beam or two or more beams for PDSCH through a DCI-based beam selection operation in one CORESET. When K is 16, the #I selected and indicated by the base station can be selected as a value from 0 to 15. Although this embodiment shows that the maximum value is configured as 16 (K=16), the maximum value can be configured as a value less than 16.

[0281] In another example, it may be determined that the base station or UE uses only Rel-16 MAC CE signaling, that is, Rel-15 MAC CE and Rel-16 MAC CE may use one Rel-16 MAC CE for C-JT / NC-JT merging.

[0282] For example, when a UE is scheduled by DCI based on Rel-15, if a TCI code point in the DCI is associated with two or more TCI states, the UE may only consider the first TCI state among the multiple TCI states. When a Rel-15 UE and a Rel-16 UE receive signaling through a merged or compatible format MAC CE, the Rel-15 UE can operate similarly to receiving a Rel-15 MAC CE defined in the current standard and obtaining the desired information. However, the Rel-16 UE may determine that at least one TCI state is selected from a plurality of TCI states selected from the DCI based on the determination of the transmission of the base station. The transmission determination method of the base station can be determined by the UE based on at least one of the information about the number of antenna ports in the DCI, the DMRS port information indicated in the DMRS table, and the TCI index information.

[0283] For example, Figure 12As shown, the base station may determine a total of M TCI states 12-00 of the TCI states configured for Rel-15 RRC, such as TCI#0, TCI#1, TCI#2, ..., TCI#M-1, where one set of TCI states for C-JT / NC-JT or at least one set of TCI states may be configured by a MAC CE (12-20). The MAC CE set may be configured to include one piece of TCI state information and at least two pieces of TCI state information for C-JT / NC-JT. For example, in this configuration, a set including one TCI state may be placed first and a set including two TCI states may be placed later, with a set including a larger number of TCI states being placed later in the listing order. In another example, the TCI states may be arranged in a listing order in which the TCI state with the smaller TCI state index is arranged first, such as TCI#0, (TCI#1, TCI#32), TCI#2, (TCI#3, TCI#34), ..., (TCI#10, TCI#31). After receiving the MAC CE, based on the DCI-based beam selection information in the DCI, one of (12-40)TCI#I or (TCI#I, TCI#J) may be indicated to the UE. In this embodiment, when TCI#I is indicated, the UE may determine that one beamforming direction is selected. Specifically, when TCI#0 is indicated, the UE may perform beamforming in the direction of the beam mapped to TCI#0. In addition, in this embodiment, when (TCI#I, TCI#J) is indicated, the Rel-15 UE may determine that TCI#I, which is the first index, is selected in the two beamforming directions. Specifically, when (TCI#1, TCI#32) is indicated, the UE can perform beamforming in the direction of the beam mapped to TCI#1 in the first TRP. In addition, in this embodiment, when (TCI#1, TCI#J) is indicated, the Rel-16 UE can determine that two beamforming directions are selected. Specifically, when (TCI#1, TCI#32) is indicated, the UE can perform beamforming in the direction of the beam mapped to TCI#1 in the first TRP, and can perform beamforming in the direction of the beam mapped to TCI#32 in the second TRP.

[0284] That is, when the UE is a Rel-15 UE, the UE can interpret only TCI#I as the first TCI status information in the information obtained from the MAC CE, and can determine a single transmission performed by one TRP. However, when the UE is a Rel-16 UE, the UE can interpret at least some or all of the MAC CE information obtained by indexing. When two TRPs for C-JT / NC-JT are configured for the UE, the UE can interpret all TCI status information as (TCI#I, TCI#J) and can determine that two beams are selected. In this embodiment, when three TRPs for C-JT / NC-JT are configured for the UE, TCI statuses such as (TCI#I, TCI#J, TCI#L) may be additionally included in the MAC CE.

[0285] When a UE is scheduled by DCI based on Rel-15, if a TCI code point in the DCI is associated with two or more TCI states, the UE may consider only the smallest TCI state ID among the multiple TCI states.

[0286] For example, Figure 12 As shown, the base station may determine a total of M TCI states 12-00 of the TCI states configured for Rel-15 RRC, such as TCI#0, TCI#1, TCI#2, ..., TCI#M-1, where one set of TCI states for C-JT / NC-JT or at least one set of TCI states may be configured by a MAC CE (12-20). The MAC CE set may be configured to include one piece of TCI state information and at least two pieces of TCI state information for C-JT / NC-JT. For example, in this configuration, a set including one TCI state may be placed first and a set including two TCI states may be placed later, with a set including a larger number of TCI states being placed later in the listing order. In another example, in the aforementioned configuration, based on the minimum value in the TCI state index, the TCI states may be arranged so that the TCI state with the smaller TCI state index is arranged in front, such as TCI#0, (TCI#32, TCI#1), TCI#2, (TCI#34, TCI#3), ..., (TCI#10, TCI#31). After receiving the MAC CE, based on the DCI-based beam selection information in the DCI, one of (12-40) TCI#1 or (TCI#1, TCI#J) may be indicated to the UE.

[0287] In this embodiment, when TCI#I is indicated, the UE can determine to select a beamforming direction. Specifically, when TCI#0 is indicated, the UE can perform beamforming in the direction of the beam mapped to TCI#0. In addition, in this embodiment, when (TCI#I, TCI#J) is indicated, the Rel-15 UE can consider the smallest TCI state ID to determine to select TCI#I (I < J) among the two beamforming directions. Specifically, when (TCI#32, TCI#1) is indicated, the UE can perform beamforming in the direction of the beam mapped to TCI#1 in the first TRP. In addition, in this embodiment, when (TCI#I, TCI#J) is indicated, the Rel-16 UE can determine to select two beamforming directions. Specifically, when (TCI#32, TCI#1) is indicated, the UE can perform beamforming in the direction of the beam mapped to TCI#1 in the first TRP, and can perform beamforming in the direction of the beam mapped to TCI#32 in the second TRP. In this embodiment, when three TRPs are configured for the UE for C-JT / NC-JT, TCI states such as (TCI#I, TCI#J, TCI#L) can be additionally included in the MAC CE.

[0288] Figure 13 Shows the structure of the MAC CE message for indicating the TCI state. Figure 13 Shows when Figure 11 in the base station selects K TCI states 11-20 from M TCI states 11-00, the structure of the MAC CE message sent to the UE to indicate the K TCI states. The MAC CE message can basically include information about the serving cell ID (e.g., 5 bits) and BWP ID (e.g., 2 bits) configured for communication between the base station and the UE. In addition, the MAC CE message requires M bits to respectively use one-bit indication to indicate whether the M TCI states are activated. As Figure 13As shown, resources in the form of octets can be used to align M bits. The indices T0, T1, ..., T(N-2)x8-7 represent TCI states respectively, and M is configured as a value equal to or greater than T(N-2)x8 and less than or equal to T(N-2)x8-7 to indicate a total of M bits. For example, in order to indicate the activated TCI state among 128 TCI states, the MAC CE message requires a total of 17 octets (N=17) of resources, including the configured serving cell ID and BWPID (Oct 1). Here, when the eight TCI states from T0 to T7 are activated, the T0 to T7 resource positions in the MAC CE message are indicated by '1', and the remaining T8 to T127 are indicated by '0'. When the UE receiving the MAC CE successfully decodes, the resource position indicated by '1' indicating the activation of the TCI state is mapped to determine the direction of the activated beamforming.

[0289] Figure 14 Various examples of multi-TRP operations according to embodiments are shown.

[0290] Figure 14 Case #4 14-30 shows an example of configuring a service cell and a physical cell identifier (PCI) according to a traditional CA operation, which is a criterion for indicating the difference between the multi-TRP operation methods. Referring to case #4, in a general CA scenario where each cell occupies different frequency resources, the base station can configure a different service cell (ServCellConfigCommon) for each cell (i.e., the frequency band value FrequencyInfoDL indicated by DownlinkConfigCommon in each service cell configuration is different), so for each cell, a different index (ServCellIndex) can be configured and a different PCI value can be mapped. Here, the parameters in ServCellConfigCommon are shown in the following table.

[0291]

[0292] Figure 14Case #1 14-00 shows intra-cell multi-TRP operation in which one or more TRPs operate within one serving cell configuration. Referring to Case #1, since the base station configures channels and signals transmitted from different TRPs to be included in one serving cell configuration, multiple TRPs operate based on one ServCellIndex (ServCellIndex#1), ​​and since there is only one ServCellIndex, only one PCI is used. In this case, when multiple SSBs are transmitted from TRP 1 and TRP 2, the SSBs have the same PCI value, and there is no problem in mapping the ServCellIndex value indicated by the cell parameters in QCL-Info to the PCI and designating the SSB transmitted from TRP 1 or TRP 2 as the reference antenna port.

[0293] Figure 14 Case #3 14-20 shows an inter-cell multi-TRP operation in which one or more TRPs have different PCIs. In case #3, the base station configures the channels and signals sent from different TRPs to be included in different service cell configurations (i.e., the corresponding TRPs have independent service cell configurations, and the frequency band value FrequencyInfoDL indicated by DownlinkConfigCommon in the service cell configuration indicates at least partially overlapping frequency bands), and since multiple TRPs operate based on multiple ServCellIndexes (ServCellIndex#1 and ServCellIndex#2) included in the service cell configuration, a separate PCI can be used for each TRP (i.e., one PCI can be allocated per ServCellIndex). When multiple SSBs are transmitted from TRP 1 and TRP 2, the SSBs may have different PCI values ​​(PCI #1 or PCI #2), and in case #3, there is no problem in mapping the PCI value appropriate for each TRP by appropriately selecting the ServCellIndex value (ServceCellIndex #1 and ServCellIndex #2) indicated by the cell parameters in the QCL-Info included in the different serving cell configurations, and designating the SSB transmitted from TRP 1 or TRP 2 as the reference antenna port. However, since this configuration uses one serving cell configuration, which can be used for CA of the UE, the degree of freedom of CA configuration may be limited or the signaling load may increase for multiple TRPs.

[0294] Figure 14Case #2 14-10 shows another example of inter-cell multi-TRP operation in which one or more TRPs have different PCIs. Referring to Case #2, the base station may configure channels and signals sent from different TRPs to be included in one serving cell configuration (taking into account the signaling load applied according to Case #3). In this case, the UE operates based on the ServCellIndex (ServCellIndex#1) included in one serving cell configuration, and therefore may not recognize the PCI (PCI#2) allocated to the second TRP. When multiple SSBs are sent from TRP 1 and TRP 2, the SSBs may have different PCI values ​​(PCI#1 or PCI#2), and in Case #2, the PCI value (PCI#2) of the second TRP may not be mapped by the ServCellIndex value indicated by the cell parameter in the QCL-Info included in one serving cell configuration. Therefore, in the inter-cell multi-TRP operation according to case #2 14-10, it is only possible to designate the SSB transmitted from TRP 1 as the reference antenna port, and it is impossible to designate the SSB transmitted from TRP 2 as the reference antenna port.

[0295] The following embodiments of the present disclosure provide methods for indicating / configuring QCL reference antenna ports to support case #2 14-10, i.e., inter-cell multi-TRP operation (inter-cell multi-TRP with non-CA framework) using a single serving cell configuration within a certain frequency resource.

[0296] The base station may explicitly or implicitly indicate to the UE through various methods that a non-CA framework is applied to the inter-cell multi-TRP.

[0297] For example, the base station may notify the UE to apply inter-cell multi-TRP with a non-CA framework through high-layer signaling, such as by "configuring parameters for dividing the CORESETs configured in one serving cell or BWP into two or more groups (CORESET groups) (high-layer parameters per CORESET)", by "configuring parameters for dividing the PUCCH resources configured in one serving cell or BWP into two or more groups (PUCCH groups) (high-layer parameters per PUCCH)", or by defining and configuring independent high-layer parameters.

[0298] In another example, when a service cell is configured to perform multi-TRP operation (i.e., when it is configured to receive one or more PDSCHs at a time in one BWP within a service cell), if the frequency resources of the service cell (i.e., the frequency resources indicated by the frequency band value FrequencyInfoDL indicated by DownlinkConfigCommon configured by the corresponding service cell) do not overlap with any frequency configuration configured by other service cells, the UE can understand that inter-cell multi-TRP with a non-CA framework is applied.

[0299] Although omitted in order not to obscure the key points described in the following embodiments, it should be noted that assuming that the UE recognizes that the base station uses the above example or one of its applications to perform inter-cell multi-TRP operations with a non-CA framework, one of the methods in the following embodiments can be applied.

[0300] [First embodiment: Method for adding PCI value to TCI configuration or QCL configuration]

[0301] The first embodiment provides a method of configuring SSB based on an additional PCI as a QCL reference antenna port by adding parameters for associating an additional PCI value other than the first PCI value mapped to the existing ServCellIndex to a TCI configuration or QCL configuration included in one serving cell configuration.

[0302] Figure 15 An example of a method of configuring a QCL target antenna port and a reference antenna port according to an embodiment is shown.

[0303] refer to Figure 15 As shown in Table 4-1, when the QCL target antenna port is TRS15-00, the configurable QCL reference antenna port can be SSB 15-05 or CSI-RS 15-10 for BM. In an inter-cell multi-TRP environment with a non-CA framework, it can be assumed that SSB 15-05 or CSI-RS 15-10 for BM is configured in the same serving cell configuration as TRS, and PCI#1 is allocated to the corresponding serving cell. Here, as described above, SSBs 15-20 and 15-30 with different PCIs (PCI#2 and PCI#3) cannot be configured as QCL reference antenna ports through legacy signaling.

[0304] According to one method for solving the above problem, as shown below, a parameter (physCellId) for referring to a PCI other than PCI #1 allocated to a serving cell may be added to a QCL configuration included in a serving cell configuration used in an inter-cell multi-TRP environment with a non-CA framework. For example, in order to configure SSBs 15-20 associated with PCI #2 as a QCL reference antenna port, the value of physCellId added to the following QCL configuration may be set to PCI #2.

[0305]

[0306] According to another method for solving the above problem, as shown below, a parameter (physCellId) for referring to a PCI other than PCI #1 allocated to the serving cell may be added to the TCI configuration included in one serving cell configuration used in an inter-cell multi-TRP environment with a non-CA framework. For example, in order to configure SSBs 15-20 associated with PCI #2 as QCL reference antenna ports, the value of physCellId added to the following TCI configuration may be set to PCI #2.

[0307]

[0308]

[0309] Similarly, in order to map different PCI values ​​to the first QCL configuration (qcl-Type1) and the second QCL configuration (qcl-Type2) in the TCI configuration, two PCIs (physcellid 1 and physCellId2) may be added to the TCI configuration as shown below.

[0310]

[0311] When allocating additional PCI values ​​to QCL configurations or TCI configurations, certain constraints may be considered in view of the mobility configuration (or handover configuration) value of the UE.

[0312] For example, according to the following table, the base station may configure a list of PCI values ​​associated with the SSB to be measured by the UE through SSB-MTC and SSB-MTC2 configurations.

[0313]

[0314]

[0315] exist Figure 15In the example of , when PCI#2 is included in the pci-list in SSB-MTC2, but PCI#3 is not included in the pci-list in SSB-MTC2, the UE is forced to measure SSBs 15-20 associated with PCI#2, but is not forced to measure SSBs 15-30 associated with PCI#3. Therefore, the UE can apply the configuration of the QCL reference antenna port to SSBs 15-20 associated with PCI#2, but does not expect the configuration of the QCL reference antenna port for SSBs 15-30 associated with PCI#3. Here, "the UE does not expect the configuration of the QCL reference antenna port" can be applied differently in actual applications, such as "ignoring the configuration details when performing the configuration", "allowing random processing to be performed because the UE operation for the configuration is not defined", or "ensuring that the base station does not perform the configuration".

[0316] As another example of specific constraints, the base station may consider a black list of cells or a white list of cells in the MeasObject configuration. According to the table below, the base station can configure a series of PCI value lists through the MeasObject configuration, which are associated with the black list (blackCellsToAddModList) and white list (whiteCellsToAddModList) of PCI values ​​that the UE considers when measuring SSB.

[0317]

[0318]

[0319]

[0320] exist Figure 15In the example of , when PCI#2 is included in the whiteCellsToAddModList (or not included in the blackCellsToAddModList) in MeasObjectNR, but PCI#3 is not included in the whiteCellsToAddModList (or included in the blackCellsToAddModList) in MeasObjectNR, the UE is forced to measure SSBs 15-20 associated with PCI#2, but is not forced to measure SSBs 15-30 associated with PCI#3. Therefore, the UE can apply the configuration of the QCL reference antenna port to SSBs 15-20 associated with PCI#2, but does not expect the configuration of the QCL reference antenna port for SSBs 15-30 associated with PCI#3. Here, "the UE does not expect the configuration of the QCL reference antenna port" can be applied differently in actual applications, such as "ignoring the configuration details when performing configuration," "allowing random processing to be performed because the UE operation for this configuration is not defined," or "ensuring that the base station does not perform this configuration."

[0321] [Second embodiment: Method of adding CSI-RS for mobility to QCL reference antenna port]

[0322] The second embodiment provides a method for referring to the PCI value of a neighboring cell by adding an antenna port (or channel / signal) for which an independent PCI value is configured regardless of the PCI value mapped to the ServCellIndex of a certain serving cell as a new QCL reference antenna port.

[0323] Figure 16 An example of a method of configuring a QCL target antenna port and a reference antenna port according to an embodiment is shown.

[0324] refer to Figure 16 As shown in Table 4-1, when the QCL target antenna port is TRS16-00, the configurable QCL reference antenna port can be SSB 16-05 or CSI-RS 16-10 for BM. In an inter-cell multi-TRP environment with a non-CA framework, it can be assumed that SSB 16-05 or CSI-RS 16-10 for BM is configured in the same serving cell configuration as TRS, and PCI#1 is allocated to the corresponding serving cell. Here, as described above, SSB 15-20 with a different PCI (PCI#2 or PCI#3) cannot be configured as a QCL reference antenna port through legacy signaling.

[0325] According to one method for solving the aforementioned problem, as shown below, it is possible to refer to a PCI other than PCI#1 allocated to a serving cell by adding a CSI-RS for mobility to an antenna port that can be selected by referenceSignal in a QCL configuration.

[0326]

[0327] In the above table, CSI-RS-Index is a parameter used to refer to the index of the following CSI-RS-Resource-Mobility configuration included in the serving cell configuration used in the inter-cell multi-TRP environment with the non-CA framework.

[0328]

[0329]

[0330] In this embodiment, some constraints may be considered when adding CSI-RS16-15 for mobility as a new QCL reference antenna port.

[0331] For example, when CSI-RS16-15 for mobility is applied as the new QCL reference antenna port, given the accuracy of the QCL application, it can be guaranteed that the density of CSI-RS for mobility is always configured to a high value (i.e., density = d3 is always configured in the CSI-RS-CellMobility configuration).

[0332] In another example, when CSI-RS16-15 for mobility is applied as a new QCL reference antenna port, the association ensures that only the UE's receive beam information is specified by limiting the QCL configuration type to QCL-type D. In this case, QCL-type A to QCL-type C can be referenced in the UE's current serving cell.

[0333] In another example, when CSI-RS 16-15 for mobility is applied as a new QCL reference antenna port, it is possible to ensure that SSB 16-20 associated with CSI-RS-Resource-Mobility (i.e., the SSB indicated by associatedSSB in CSI-RS-Resource-Mobility) is applied as the QCL reference antenna port instead of directly using CSI-RS 16-15 for mobility. Here, by configuring isQuasiColocated in associatedSSB, it can be ensured that this example is applied only when the CSI-RS for mobility and the associated SSB are QCL-compliant with each other.

[0334] [Third embodiment: Method for satisfying the conditions for using a TRS that is not configured as a QCL reference antenna port]

[0335] The third embodiment relates to a method for performing appropriate operations according to a scenario in which no reference to the PCI value of an adjacent TRP is required, that is, a scenario in which an additional QCL reference antenna port is configured in addition to the QCL reference antenna port based on the service cell as needed and a scenario in which no additional QCL reference antenna port is required to be configured.

[0336] Figure 17 Intra-cell multi-TRP operation and inter-cell multi-TRP operation according to an embodiment are shown.

[0337] refer to Figure 17 , the UE may perform a UE capability report on multi-TRP operation (17-00). The UE capability report on multi-TRP operation may report together whether intra-cell multi-TRP operation is possible and whether inter-cell multi-TRP operation is possible (i.e., report whether both operations are possible or not), or may report separately whether both operations are possible. Subsequently, the base station may configure multi-TRP operation for the UE capable of multi-TRP operation (17-05). The UE may determine whether inter-cell multi-TRP operation is feasible according to pre-agreed rules, that is, whether TRS reception is possible without configuring the QCL reference antenna port (17-10). For example, in the pre-agreed rules, when the deriveSSB-IndexFromCell parameter is configured to true, the base station aligns the subframe number (SFN) and frame boundary for each cell. When inter-cell multi-TRP operation is not possible, the UE may receive a configured QCL reference antenna port based on the serving cell PCI to perform intra-cell multi-TRP operation (17-15). When inter-cell multi-TRP operation is possible, the UE can perform intra-cell multi-TRP operation without configuring QCL reference antenna ports (17-20).

[0338] In the above embodiment, it is assumed that TRS15-00 and 16-00 are target antenna ports, but the present disclosure is not limited thereto, and a method similar to the above method may be applied to other types of target antenna ports.

[0339] [Fourth embodiment: Method for adding a PCI value to an SSB-based channel state measurement configuration]

[0340] This embodiment provides a method in which, in a multi-TRP scenario between cells in a non-CA framework, RS (e.g., SSB or CSI-RS for mobility) sent in a cell or TRP of a PCI to which the UE is not attached / resident is used as a reference signal for channel state measurement.

[0341] First, a method for configuring reference signals for L1-RSRP or L1-SINR measurement is provided. Conventional reference signal configuration for L1-RSRP or L1-SINR measurement is indicated from the base station to the UE via the CSI-ResourceConfig IE or similar signaling structure. As shown in the following table, the reference signal type that can be configured for L1-RSRP or L1-SINR measurement can be SSB, CSI-RS, or CSI-IM.

[0342]

[0343] When SSB is configured in the CSI-ResourceConfig IE of the table, a list of SSB sets for measuring L1-RSRP or L1-SINR can be indicated in the csi-SSB-ResourceSetList element. Each SSB set in the csi-SSB-ResourceSetList element can include the ID of the SSB set (csi-SSB-ResourceSetId) and a list of SSB indices belonging to the SSB set (csi-SSB-ResourceList), as shown in the following table.

[0344]

[0345] The SSB index belonging to the conventional SSB set is limited to the PCell to which the UE is attached or resides or the SCell configured for the UE. According to an embodiment of the present disclosure, in order to use an SSB that is a PCell to which the UE is not attached or resides or a cell that is a PCI that is not configured as an SCell, or a TRP for L1-RSRP or L1-SINR measurement, the base station can indicate not only the SSB index to the UE but also the PCI corresponding to the SSB index to the UE. When indicating the PCI, a separate PCI can be indicated for each SSB index in the SSB set, one PCI can be indicated for each SSB set, or one PCI can be indicated for each CSI-ResourceConFigure. For example, when one PCI is indicated for each SSB set, the parameter indicating the PCI (physCellId) can be added to the SSB set configuration (csi-SSB-ResourceList) as follows.

[0346]

[0347] Next, a method for configuring a reference signal for beam failure recovery is provided. After periodically measuring the reference signal corresponding to a specific link, when the UE determines that the reception quality (e.g., RSRP) of the reference signal is not good, the UE can declare that the beam in the link has failed and can perform a beam recovery process. The beam recovery process can start with the UE sending beam failure declaration information to the base station. The beam failure declaration information may include information about the link that needs to be recovered and information about the beam used to recover the link. The information about the link that needs to be recovered may include the index of the serving cell of the link and / or information about the reference signal periodically measured in the serving cell. The "periodically measured reference signal" may be referred to as a beam failure detection (BFD) reference signal. The information about the beam used to recover the link may include the index of a new reference signal with good reception quality selected by the UE. The "new reference signal with good reception quality" may be referred to as a candidate beam detection (CBD) reference signal.

[0348] In the conventional beam recovery process, SSB and CSI-RS can be used as BFD RS and CBD RS, and the conventionally available SSB is limited to the SSB belonging to the PCell to which the UE is attached or resides or the SCell configured for the UE. Therefore, according to an embodiment of the present disclosure, in order to use an SSB that is a cell or TRP that is a PCell to which the UE is not attached or resides or a PCI that is not configured as an SCell, when the SSB is indicated as a BFD RS and / or CBD RS, the PCI to which the SSB belongs can also be indicated. For example, when an SSB is used as a BFD RS and / or CBD RS for the beam recovery process of a PCell, a parameter indicating the PCI (physCellId) can be indicated together with the SSB index, as shown in the following table.

[0349]

[0350] The default value of the PCI parameter configured in the aforementioned embodiment may be configured. For example, when the physCellId is not indicated, the default value of the physCellId may be the PCI of the PCell or configured SCell to which the UE is attached or resides.

[0351] Next, in the aforementioned embodiment, it can be determined whether the PCI parameters can be configured in the SSB according to the UE capability report, which can be similar to Figure 17. The UE capability report on multi-TRP operation may report together whether intra-cell multi-TRP operation is possible and whether inter-cell multi-TRP operation is possible (i.e., report whether both operations are possible or not), or may report separately whether both operations are possible. Subsequently, the base station may configure multi-TRP operation for UEs capable of multi-TRP operation. The configuration of multi-TRP operation refers to the configuration for measuring the SSB sent to inter-cell multi-TRP for L1-RSRP / L1-SINR measurement or BFD / CBD process. When configuring this operation, pre-agreed constraints may be additionally configured. For example, the pre-agreed constraints may be a condition in which the deriveSSB-IndexFromCell parameter is configured to true, so that the base station aligns the subframe number (SFN) and frame boundary for each cell. When inter-cell multi-TRP operation is not possible, the base station may be configured not to perform multi-TRP operation, that is, when using SSB for L1-RSRP / L1-SINR measurement or BFD / CBD process, only the SSB of the serving cell is used. According to the aforementioned configuration, the UE can perform multi-TRP operation between cells or only perform single-cell operation.

[0352] According to the embodiments of the present disclosure described above, in a wireless communication system, a base station may send at least one MAC control element (MAC CE) and downlink control information (DCI) to allocate multiple physical downlink shared channels (PDSCHs) to multiple UEs to support joint transmission (JT).

[0353] According to an embodiment of the present disclosure, a method for a UE to perform communication in a wireless communication system may include: an operation of sending capability information about the UE to a base station, the capability information including information about whether collaborative communication is supported; an operation of obtaining information about whether collaborative communication is activated from the base station through radio resource control (RRC) when the UE supports collaborative communication; an operation of identifying the format of a MAC control element (CE) received from the base station based on whether the base station activates collaborative communication; an operation of determining a transmission configuration indication (TCI) state per transmit receive point (TRP) based on the format of the identified MAC CE; and an operation of receiving a PDSCH sent from one or more TRPs by referring to the determined one or more TCI states.

[0354] According to an embodiment of the present disclosure, a method for a UE to perform communication in a wireless communication system may include: an operation of sending capability information about the UE to a base station, the capability information including information about whether collaborative communication is supported; when the UE supports collaborative communication, an operation of obtaining information about whether collaborative communication is activated from the base station through radio resource control (RRC); an operation of detecting downlink control information (DCI) sent from the base station based on whether the base station activates collaborative communication; and when two or more of the detected DCIs perform PDSCH allocation for specific time / frequency resources, an operation of receiving the PDSCH allocated by each DCI by referring to a transmission configuration indication (TCI) state indicated by each DCI.

[0355] In the method for a UE to perform communication in a wireless communication system according to an embodiment of the present disclosure, the operation of determining the TCI state may include: when cooperative communication is activated, the base station identifies information about one or more TCI states activated according to one or more MAC CEs.

[0356] In a method for a UE to perform communication in a wireless communication system according to an embodiment of the present disclosure, the operation of determining a TCI state may include: when cooperative communication is activated, the base station identifies information about one or more TCI states indicated by one or more DCIs.

[0357] In a method for a UE to perform communication in a wireless communication system according to an embodiment of the present disclosure, the operation of determining the TCI state may include the following operations: when collaborative communication is activated, the base station refers to a first physical cell identifier (PCI) for one quasi-co-location (QCL) information and refers to a second PCI for another QCL information when referring to QCL information based on one or more TCI states indicated from one or more DCIs.

[0358] The method for a UE to perform communication in a wireless communication system according to an embodiment of the present disclosure may further include an operation of updating a beam direction of a PDCCH or PDSCH based on an activated TCI state pair per TRP included in a MAC CE.

[0359] According to an embodiment of the present disclosure, the method for a UE to perform communication in a wireless communication system may also include: an operation of receiving downlink control information (DCI); and an operation of determining a DMRS port for collaborative communication from a preset field in the received DCI when it is determined that the base station activates collaborative communication.

[0360] According to an embodiment of the present disclosure, the method for a UE to perform communication in a wireless communication system may also include: when it is determined that the base station activates collaborative communication, an operation of identifying a field including information about a DMRS port used for collaborative communication from a preset field in the DCI received from the base station; and an operation of determining the DMRS port used for collaborative communication based on a value included in the identified field.

[0361] According to an embodiment, a method for a base station to perform communication in a wireless communication system may include: an operation of receiving capability information about a UE, the capability information including information about whether collaborative communication is supported; when the UE supports collaborative communication, an operation of sending information about whether collaborative communication is activated to the UE through RRC; and an operation of sending a MAC control element (CE), the MAC CE including information about the transmission configuration indication (TCI) status of multiple transmit receive points (TRPs).

[0362] Figure 18 is a block diagram illustrating the structure of a UE according to some embodiments.

[0363] refer to Figure 18 , the UE may include a UE receiver 18-00, a UE transmitter 18-10, and a UE processor 18-05. The UE receiver 18-00 and the UE transmitter 18-10 may be collectively referred to as a transceiver. The UE receiver 18-00, the UE transmitter 18-10, and the UE processor 18-05 of the UE may operate according to the aforementioned communication method of the UE. However, the components of the UE are not limited to the aforementioned examples. For example, the UE may include more components (e.g., memory) or fewer components than the aforementioned components. In addition, the UE receiver 18-00, the UE transmitter 18-10, and the UE processor 18-05 may be configured as a single chip.

[0364] The UE receiver 18-00 and the UE transmitter 18-10 (or transceiver) can transmit and receive signals to and from the base station. Here, the signals may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting the frequency of the transmitted signal and amplifying it, and an RF receiver for performing low-noise amplification of the received signal and down-converting the frequency of the received signal. However, this is merely an embodiment of a transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0365] In addition, the transceiver may receive a signal through a radio channel to output the signal to the UE processor 18 - 05 , and may transmit a signal output from the UE processor 18 - 05 through the radio channel.

[0366] The memory (not shown) can store programs and data required for UE operation. In addition, the memory can store control information or data included in the signal obtained by the UE. The memory can be configured as a storage medium such as ROM, RAM, hard disk, CD-ROM and DVD, or a combination of storage media.

[0367] The UE processor 18-05 may control a series of processes so that the UE may operate according to the aforementioned embodiments of the present disclosure. The UE processor 18-05 may be configured as a controller or one or more processors.

[0368] Figure 19 is a block diagram illustrating the structure of a base station according to some embodiments.

[0369] refer to Figure 19 , the base station may include a base station receiver 19-00, a base station transmitter 19-10, and a base station processor 19-05. The base station receiver 19-00 and the base station transmitter 19-10 may be collectively referred to as a transceiver. The base station receiver 19-00, the base station transmitter 19-10, and the base station processor 19-05 of the base station may operate according to the aforementioned communication method of the base station. However, the components of the base station are not limited to the aforementioned examples. For example, the base station may include more components (e.g., memory) or fewer components than the aforementioned components. In addition, the base station receiver 19-00, the base station transmitter 19-10, and the base station processor 19-05 may be configured as a single chip.

[0370] The base station receiver 19-00 and the base station transmitter 19-10 (or transceiver) can send and receive signals to and from the UE. Here, the signals may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting the frequency of the transmitted signal and amplifying it, and an RF receiver for performing low-noise amplification of the received signal and down-converting the frequency of the received signal. However, this is merely an embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and the RF receiver.

[0371] In addition, the transceiver can receive a signal through a radio channel to output the signal to the base station processor 19-05, and can transmit a signal output from the base station processor 19-05 through the radio channel.

[0372] The memory (not shown) can store programs and data required for base station operation. In addition, the memory can store control information or data included in the signal obtained by the base station. The memory can be configured as a storage medium such as ROM, RAM, hard disk, CD-ROM and DVD, or a combination of storage media.

[0373] The base station processor 19-05 may control a series of processes so that the base station can operate according to the aforementioned embodiments. The base station processor 19-05 may be configured as a controller or one or more processors.

[0374] The embodiments of the present disclosure described and illustrated in the specification and drawings are merely specific examples, which are presented to easily explain the technical content of the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations of the technical ideas based on the embodiments can be implemented. In addition, the above-mentioned various embodiments can be used in combination as needed. For example, embodiments 1 to 4 of the present disclosure can be combined in whole or in part to operate a base station and a terminal.

Claims

1. A method performed by a user equipment (UE) in a communication system, the method comprising: receiving transmission configuration indicator TCI status information from a base station; and identifying a quasi-co-located QCL reference signal associated with the TCI state information, Among them, the TCI status information indicates that the synchronization signal block SSB is used as the QCL reference signal. The TCI status information includes information indicating the physical cell identifier PCI of the SSB, and Among them, the PCI of SSB is different from the PCI of the service cell.

2. The method according to claim 1, further comprising: receiving information of a list of PCIs for a PCI different from the PCI of the serving cell from the base station, Here, the information indicating the PCI of the SSB is information based on a list of PCIs used for a cell different from the PCI of the serving cell.

3. The method according to claim 2, wherein: The information of the list for PCIs different from the PCI of the serving cell is based on the configuration information for the SSB to be measured.

4. The method according to claim 1, wherein The TCI status information is associated with a non-zero power NZP channel state information reference signal CSI-RS, and Among them, the SSB with PCI different from the PCI of the serving cell is the QCL reference signal of the NZP CSI-RS.

5. A method performed by a base station in a communication system, the method comprising: identifying a quasi-co-located QCL reference signal associated with transmission configuration indicator TCI status information; and Send TCI status information to user equipment UE, Among them, the TCI status information indicates that the synchronization signal block SSB is used as the QCL reference signal. The TCI status information includes information indicating the physical cell identifier PCI of the SSB, and Among them, the PCI of SSB is different from the PCI of the service cell.

6. The method according to claim 5, further comprising: Sending information of a list of PCIs different from the PCI of the serving cell to the UE, Here, the information indicating the PCI of the SSB is information based on a list of PCIs used for a cell different from the PCI of the serving cell.

7. The method according to claim 6, wherein: The information of the list for PCIs different from the PCI of the serving cell is based on the configuration information for the SSB to be measured.

8. The method according to claim 5, wherein The TCI status information is associated with a non-zero power NZP channel state information reference signal CSI-RS, and Among them, the SSB with PCI different from the PCI of the serving cell is the QCL reference signal of the NZP CSI-RS.

9. A user equipment (UE) in a communication system, the UE comprising: transceiver; and The controller is configured as: receiving transmission configuration indicator TCI status information from a base station; and identifying a quasi-co-located QCL reference signal associated with the TCI state information, Among them, the TCI status information indicates that the synchronization signal block SSB is used as the QCL reference signal. The TCI status information includes information indicating the physical cell identifier PCI of the SSB, and Among them, the PCI of SSB is different from the PCI of the service cell.

10. The UE according to claim 9, wherein: The controller is further configured to: receiving information of a list of PCIs for a PCI different from the PCI of the serving cell from the base station, Here, the information indicating the PCI of the SSB is information based on a list of PCIs used for a cell different from the PCI of the serving cell.

11. The UE according to claim 10, wherein: The information of the list for PCIs different from the PCI of the serving cell is based on the configuration information for the SSB to be measured.

12. The UE according to claim 9, wherein: The TCI status information is associated with a non-zero power NZP channel state information reference signal CSI-RS, and Among them, the SSB with PCI different from the PCI of the serving cell is the QCL reference signal of the NZP CSI-RS.

13. A base station in a communication system, the base station comprising: transceiver; and The controller is configured as: identifying a quasi-co-located QCL reference signal associated with transmission configuration indicator TCI status information; and Send TCI status information to user equipment UE, Among them, the TCI status information indicates that the synchronization signal block SSB is used as the QCL reference signal. The TCI status information includes information indicating the physical cell identifier PCI of the SSB, and Among them, the PCI of SSB is different from the PCI of the service cell.

14. The base station according to claim 13, wherein: The controller is further configured to: Sending information of a list of PCIs different from the PCI of the serving cell to the UE, Here, the information indicating the PCI of the SSB is information based on a list of PCIs used for a cell different from the PCI of the serving cell.

15. The base station according to claim 14, wherein: The information of the list for PCIs different from the PCI of the serving cell is based on the configuration information for the SSB to be measured.

16. The base station according to claim 13, wherein: The TCI status information is associated with a non-zero power NZP channel state information reference signal CSI-RS, and Among them, the SSB with PCI different from the PCI of the serving cell is the QCL reference signal of the NZP CSI-RS.

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