Method and apparatus for receiving downlink control channels and transmitting uplink control channels in a wireless communication system

Abstract

A method and apparatus for receiving and transmitting signals / channels in a wireless communication system are provided. The method performed by a terminal includes receiving configuration information for a first search space (SS) set and a second SS set, where the first SS set having a first index includes a first PDCCH candidate having CCE AL 8 and a third PDCCH candidate having CCE AL 16, and the second SS set having a second index includes a second PDCCH candidate having CCE AL 8 and a fourth PDCCH candidate having CCE AL 16, receiving a PDCCH based on the configuration information, determining a PUCCH resource based on an index of a first CCE for the PDCCH, where if the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE is determined based on a CCE AL of a PDCCH candidate associated with the second SS set having the second index, and transmitting a PUCCH based on the determined PUCCH resource.

Description

[Technical Field]

[0001] This disclosure relates to the operation of terminals (UEs) and base stations (BSs) in wireless communication systems. More specifically, this disclosure relates to a method for receiving a downlink (DL) control channel of a terminal and a downlink shared channel based on said reception, and an apparatus capable of performing said method. This disclosure also relates to a method for receiving a downlink control channel of a terminal and a uplink (UL) control channel based on said reception, and an apparatus capable of performing said method. [Background technology]

[0002] 5G mobile communication technology defines a wide frequency band to enable faster transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5 GHz), but also in the ultra-high frequency band known as millimeter wave (mmWave) such as 28 GHz and 39 GHz ("Above 6GHz"). Furthermore, 6G mobile communication technology, referred to as the system beyond 5G, is considering implementation in the terahertz band (for example, the 95 GHz to 3 terahertz (3 THz) band) to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, the goal was to satisfy the service support and performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). This included beamforming and Massive MIMO to mitigate path loss and increase transmission distance in the ultra-high frequency band, various numerology support (such as operation of multiple subcarrier spacings) and dynamic operation of slot formats for efficient utilization of ultra-high frequency resources, initial connection technologies to support multiple beam transmission and broadband, definition and operation of Band-Width Parts (BWP), new channel coding methods such as Low-Density Parity Check (LDPC) codes for high-capacity data transmission and Polar Code for highly reliable transmission of control information, L2 pre-processing, and network slicing to provide dedicated networks specialized for specific services. Standardization efforts were made for techniques such as slicing.

[0004] Currently, discussions are underway for initial improvements and enhancements to 5G mobile communication technology, taking into account the services that 5G mobile communication technology is intended to support. Physical layer standardization is progressing for technologies such as V2X (Vehicle-to-Everything), which helps autonomous vehicles make driving decisions based on their transmitted location and status information to increase user convenience; NR-U (New Radio Unlicensed), which aims for system operation in unlicensed bands that complies with various regulatory requirements; NR terminal low power consumption technology (UE Power Saving); Non-Terrestrial Network (NTN), which is terminal-satellite direct communication to ensure coverage in areas where communication with terrestrial networks is impossible; and positioning.

[0005] Furthermore, standardization is underway in the field of wireless interface architecture / protocols for technologies such as Intelligent Factories (Industrial Internet of Things, IIoT) for supporting new services using collaboration and integration with other industries, Integrated Access and Backhaul (IAB) for providing nodes for network service area expansion by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step RACH for NR for simplifying random access procedures. Standardization is also underway in the field of system architecture / services for 5G baseline architectures (e.g., Service-based Architecture, Service-based Interface) for the integration of Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) where services are provided based on the location of the terminal.

[0006] With the commercialization of such 5G mobile communication systems, the explosively increasing number of connected devices will be linked to the communication network. Therefore, it is expected that enhancements to the functionality and performance of 5G mobile communication systems and the integrated operation of connected devices will be necessary. To this end, new research is planned to be conducted on improving 5G performance and reducing complexity using augmented reality (eXR), artificial intelligence (AI), and machine learning (ML) to efficiently support augmented reality (AR), virtual reality (VR), and mixed reality (MR), as well as AI service support, metabus service support, and drone communication.

[0007] Furthermore, the development of such 5G mobile communication systems could serve as a foundation for the development of new technologies for 6G mobile communication, including new waveforms to ensure terahertz band coverage, multiplex antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas, metamaterial-based lenses and antennas to improve terahertz band signal coverage, high-dimensional spatial multiplexing technologies using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface) technologies, as well as full duplex technologies to improve frequency efficiency and system network improvements for 6G mobile communication, satellites, AI-based communication technologies that utilize AI (Artificial Intelligence) from the design stage and internalize end-to-end AI support functions to optimize the system, and next-generation distributed computing technologies that realize services of a complexity exceeding the limits of terminal computing power by utilizing ultra-high-performance communication and computing resources.

[0008] The above information described in this background technical information is for improving the understanding of the present disclosure, and no determination or assertion has been made as to whether any of the above is applicable as prior art in relation to the present disclosure.

Summary of the Invention

Problems to be Solved by the Invention

[0009] According to an embodiment, an apparatus and method capable of effectively providing a service in a mobile communication system are provided.

[0010] Specifically, a method for receiving a downlink control channel of a terminal and a downlink shared channel based on the reception, and an apparatus capable of executing the method are provided.

[0011] Also, a method for receiving a downlink control channel of a terminal and transmitting an uplink control channel based on the reception, and an apparatus capable of executing the method are provided.

Means for Solving the Problems

[0012] The present invention has been made to solve the above-described problems and disadvantages and to provide at least the following advantages.

[0013] According to one aspect of the present disclosure, a method performed by a terminal in a wireless communication system includes the steps of: receiving configuration information for a first search space (SS) set and a second SS set, wherein the first SS set having a first index includes a first PDCCH (physical downlink control channel) candidate having a CCE (control channel element) integration level (AL) 8 and a third PDCCH candidate having a CCE AL 16, and the second SS set having a second index includes a second PDCCH candidate having a CCE AL 8 and a fourth PDCCH candidate having a CCE AL 16; receiving a PDCCH based on the configuration information; determining a PUCCH (physical uplink control channel) resource based on the index of the first CCE for the PDCCH, wherein if the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE is determined based on the CCE AL of the PDCCH candidate associated with the second SS set having the second index; and transmitting a PUCCH based on the determined PUCCH resource.

[0014] According to yet another aspect of the present disclosure, a method performed by a base station in a wireless communication system includes the steps of: transmitting configuration information for a first search space (SS) set and a second SS set to a terminal, wherein the first SS set having a first index includes a first PDCCH candidate having a CCE integration level (AL) 8 and a third PDCCH candidate having a CCE AL 16, and the second SS set having a second index includes a second PDCCH candidate having a CCE AL 8 and a fourth PDCCH candidate having a CCE AL 16; transmitting a PDCCH to the terminal based on the configuration information; and receiving a PUCCH from the terminal based on a PUCCH resource, wherein the PUCCH resource is identified based on the index of the first CCE for the PDCCH, and if the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE for the PDCCH is associated with the CCE AL of the PDCCH candidate associated with the second SS set having the second index.

[0015] According to yet another aspect of this disclosure, a terminal in a wireless communication system includes a transmitting and receiving unit for transmitting and receiving signals, and a control unit connected to the transmitting and receiving unit. The control unit receives setting information for a first search space (SS) set and a second SS set via the transmitting / receiving unit. The first SS set, having a first index, includes a first PDCCH candidate having a CCE integration level (AL) 8 and a third PDCCH candidate having a CCE AL 16. The second SS set, having a second index, includes a second PDCCH candidate having a CCE AL 8 and a fourth PDCCH candidate having a CCE AL 16. The control unit receives PDCCHs via the transmitting / receiving unit based on the setting information and determines a PUCCH resource based on the index of the first CCE for the PDCCH. If the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE is determined based on the CCE AL of the PDCCH candidate associated with the second SS set having the second index, and the control unit is configured to transmit a PUCCH via the transmitting / receiving unit based on the determined PUCCH resource.

[0016] According to yet another aspect of the present disclosure, a base station in a wireless communication system includes a transmitting / receiving unit for transmitting and receiving signals, and a control unit connected to the transmitting / receiving unit. The control unit transmits configuration information for a first search space (SS) set and a second SS set to a terminal, wherein the first SS set having a first index includes a first PDCCH candidate having a CCE integration level (AL) 8 and a third PDCCH candidate having a CCE AL 16, and the second SS set having a second index includes a second PDCCH candidate having a CCE AL 8 and a fourth PDCCH candidate having a CCE AL 16, and is configured to transmit a PDCCH to the terminal based on the configuration information and to receive a PUCCH from the terminal based on a PUCCH resource, the PUCCH resource is verified based on the index of the first CCE for the PDCCH, and if the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE for the PDCCH is associated with the CCE AL of the PDCCH candidate associated with the second SS set having the second index.

[0017] In yet another aspect of this disclosure, the process comprises the steps of: the terminal receiving settings for a plurality of search spaces from a base station; the terminal receiving settings for linked search spaces from the base station that repeatedly transmit the same DCI among the plurality of search spaces; the terminal receiving DCIs that schedule PDSCHs in the linked search spaces; the terminal determining the aggregation level of the PDCCHs to which the received DCIs are transmitted based on the search space setting information of each of the linked search spaces; and the terminal receiving PDSCHs by rate matching them based on the aggregation level determined in each search space.

[0018] In yet another aspect of this disclosure, the process comprises the steps of: the terminal receiving settings for multiple search spaces from a base station; the terminal receiving settings for linked search spaces from the base station that repeatedly transmit the same DCI among the multiple search spaces; the terminal receiving a DCI that schedules a PDSCH in the linked search space; the terminal determining a search space that satisfies specific conditions based on the settings information of the linked search space; the terminal determining an aggregation level in the search space that satisfies the specific conditions; the terminal determining an aggregation level in a search space that does not satisfy the specific conditions based on the determined aggregation level; and the terminal receiving a PDSCH by rate matching based on the aggregation level determined in the search space that satisfies the specific conditions and the aggregation level determined in the search space that does not satisfy the specific conditions.

[0019] In yet another aspect of this disclosure, the process comprises the steps of: the terminal receiving settings for multiple search spaces from a base station; the terminal receiving settings for linked search spaces from the base station that repeatedly transmit the same DCI among the multiple search spaces; the terminal receiving a DCI that schedules a PDSCH in the linked search space; the terminal determining a search space that does not satisfy specific conditions based on the settings information of the linked search space; the terminal determining an aggregation level in the search space that does not satisfy the specific conditions; the terminal determining an aggregation level in a search space that satisfies specific conditions based on the determined aggregation level; and the terminal receiving a PDSCH by rate matching based on the aggregation level determined in the search space that does not satisfy the specific conditions and the aggregation level determined in the search space that satisfies specific conditions.

[0020] The technical challenges to be addressed in the embodiments of this disclosure are not limited to those mentioned above, and other technical challenges not mentioned above will be clearly understood by a person with ordinary skill in the art to which this disclosure pertains from the following description. [Effects of the Invention]

[0021] The disclosed embodiments can provide apparatus and methods capable of effectively providing services in a mobile communication system.

[0022] According to one embodiment of this disclosure, resources used for PDCCH monitoring can be determined in multiple linked search spaces, and PDSCH rate matching can be performed based on these resources.

[0023] Furthermore, according to one embodiment of the present disclosure, a PUCCH resource can be determined based on PDCCHs received in multiple linked search spaces, and a PUCCH including a HARQ-ACK can be transmitted based on the determined resource.

[0024] The effects derived from this disclosure are not limited to those described above, and other effects not mentioned herein will be clearly understood by those with ordinary skill in the art to which this invention pertains from the following description. [Brief explanation of the drawing]

[0025] The above and other aspects, features and advantages of the specific embodiments of this disclosure will become more apparent from the following description taken together with the accompanying drawings: [Figure 1] This figure shows the basic structure in the time-frequency domain of a wireless communication system according to one embodiment of the present disclosure. [Figure 2] This figure shows the frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure. [Figure 3] A partial bandwidth setting is shown in a wireless communication system according to one embodiment of this disclosure. [Figure 4] This document shows the control area setting for the downlink control channel in a wireless communication system according to one embodiment of the present disclosure. [Figure 5] This figure shows the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure. [Figure 6]This figure illustrates how a base station and a terminal transmit and receive data in a wireless communication system according to one embodiment of the present disclosure, taking into account the downlink data channel and rate matching resources. [Figure 7] This figure shows an example of frequency axis resource allocation for a PDSCH in a wireless communication system according to one embodiment of the present disclosure. [Figure 8] This figure shows an example of time-axis resource allocation for a PDSCH in a wireless communication system according to one embodiment of the present disclosure. [Figure 9] This figure shows an example of time-axis resource allocation based on the subcarrier interval of the data channel and control channel in a wireless communication system according to one embodiment of the present disclosure. [Figure 10] This figure shows the wireless protocol structure of the base station and terminal in a wireless communication system according to one embodiment of the present disclosure, under single cell, carrier aggregation, and dual connectivity conditions. [Figure 11] This disclosure presents an example of PDSCH rate matching considering repeated PDCCH transmission according to one embodiment of this disclosure. [Figure 12] An example of a PDSCH rate matching method is shown when a PDCCH candidate according to one embodiment of this disclosure overlaps with a reserved resource. [Figure 13] This invention presents an example of a method for determining PDSCH rate matching based on whether or not each PDCCH candidate for each search space can be received, according to one embodiment of this disclosure. [Figure 14A] This figure shows the ambiguity of the integration level determination according to one embodiment of the present disclosure. [Figure 14B] This figure shows the ambiguity of the integration level determination according to one embodiment of the present disclosure. [Figure 14C] This figure shows the ambiguity of the integration level determination according to one embodiment of the present disclosure. [Figure 14D] This figure shows the ambiguity of the integration level determination according to one embodiment of the present disclosure. [Figure 15A]This figure shows the rate matching of PDSCH in the case of ambiguity in the integration level determination according to one embodiment of the present disclosure. [Figure 15B] This figure shows the rate matching of PDSCH in the case of ambiguity in the integration level determination according to one embodiment of the present disclosure. [Figure 16] This document provides an example illustrating a situation in which some of the PDCCH candidates in one embodiment of this disclosure are not monitored. [Figure 17] This disclosure presents an example of a PDSCH rate matching method that takes into account the ambiguity of PDCCH repetitive transmission and aggregation level determination, as well as reserved resources, according to one embodiment of this disclosure. [Figure 18] This disclosure presents an example of a PDSCH rate matching method that takes into account the ambiguity of PDCCH repetitive transmission and aggregation level determination, as well as reserved resources, according to one embodiment of this disclosure. [Figure 19] This disclosure presents an example of a PDSCH rate matching method that takes into account the ambiguity of PDCCH repetitive transmission and aggregation level determination, as well as reserved resources, according to one embodiment of this disclosure. [Figure 20] This disclosure presents an example of a PDSCH rate matching method that takes into account the ambiguity of PDCCH repetitive transmission and aggregation level determination, as well as reserved resources, according to one embodiment of this disclosure. [Figure 21] This figure shows PDSCH rate matching in the case of ambiguity in PDCCH repeated transmission and aggregation level determination according to one embodiment of the present disclosure. [Figure 22] This figure shows PDSCH rate matching in the case of ambiguity in PDCCH repeated transmission and aggregation level determination according to one embodiment of the present disclosure. [Figure 23A] This figure shows PDSCH rate matching in the case of ambiguity in PDCCH repeated transmission and aggregation level determination according to one embodiment of the present disclosure. [Figure 23B] This figure shows PDSCH rate matching in the case of ambiguity in PDCCH repeated transmission and aggregation level determination according to one embodiment of the present disclosure. [Figure 24] This is a flowchart of a PDSCH rate matching method according to one embodiment of the present disclosure. [Figure 25] This is a flowchart of a PDSCH rate matching method according to one embodiment of the present disclosure. [Figure 26] This is a flowchart of a PDSCH rate matching method according to one embodiment of the present disclosure. [Figure 27] An example of a method for determining PUCCH resources according to one embodiment of this disclosure is shown. [Figure 28] This invention provides an example of a method for determining PUCCH resources in cases of ambiguity in PDCCH repetitive transmission and aggregation level determination according to one embodiment of this disclosure. [Figure 29] This is an example of a flowchart illustrating terminal operation according to one embodiment of the present disclosure. [Figure 30] This figure shows the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure. [Figure 31] This figure shows the structure of a base station in a wireless communication system according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0026] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings.

[0027] Furthermore, explanations of technical content that is well-known in the field of technology to which this disclosure pertains and is not directly related to this disclosure will be omitted. This is to ensure that the gist of this disclosure is communicated more clearly without becoming ambiguous by omitting unnecessary explanations.

[0028] For similar reasons, some components in the attached drawings are exaggerated, omitted, or shown schematically. Furthermore, the sizes of each component do not fully reflect their actual size. The same or corresponding components are given the same reference number in each drawing.

[0029] The various advantages and features of this disclosure, and the methods for achieving them, will become clear from the embodiments described below in detail with accompanying drawings. However, this disclosure is not limited to the embodiments disclosed below and may be embodied in a variety of different forms, and these embodiments are provided merely to complete the disclosure and to fully inform a person ordinary skill in the art to which this disclosure belongs of the scope of the disclosure, and this disclosure is defined only by the scope of the claims.

[0030] Throughout the specification, the same reference numeral represents the same component.

[0031] Furthermore, the terms described below are defined in consideration of the functions described herein, and these may change depending on the intent or practice of the user or operator. Therefore, their definitions should be based on the content of this specification as a whole.

[0032] Hereinafter, a base station is the entity responsible for allocating resources to terminals and may be at least one of the following: gNode B, eNode B, Node B, BS (Base Station), wireless connection unit, base station controller, or node on the network. Terminals may include UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or multimedia system capable of communication functions.

[0033] In this disclosure, Downlink (DL) refers to the radio transmission path of signals transmitted from a base station to a terminal, and Uplink (UL) refers to the radio transmission path of signals transmitted from a terminal to a base station. While LTE (Long-Term Evolution) or LTE-A (LTE-advanced) systems may be used as examples in the following description, embodiments of this disclosure may also be applied to other communication systems with similar technical backgrounds or channel configurations. For example, this may include fifth-generation mobile communication technologies (5G, new radio, NR) developed after LTE-A, and the hereafter referred to as 5G may be a concept encompassing existing LTE, LTE-A, and other similar services. Furthermore, this disclosure may be applied to other communication systems with some modifications, at the discretion of a person with skilled technical knowledge, without significantly departing from the scope of this disclosure.

[0034] In this case, each block of the flowchart and the combination of the flowchart may be performed by computer program instructions. These computer program instructions may be implemented on the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, and so the instructions performed by the processor of the computer or other programmable data processing equipment will generate means to perform the functions described in the blocks of the flowchart. These computer program instructions may also be stored in computer-available or computer-readable memory that can be directed to the computer or other programmable data processing equipment in order to embody the functions in a particular manner, and so the instructions stored in that computer-available or computer-readable memory may produce a manufactured product that contains instruction means to perform the functions described in the blocks of the flowchart. Since computer program instructions may also be implemented on the computer or other programmable data processing equipment, instructions that perform a series of operational steps on the computer or other programmable data processing equipment to generate a process executed on the computer may also provide steps for performing the functions described in the blocks of the flowchart.

[0035] Furthermore, each block may represent a module, segment, or portion of code containing one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative execution examples, the functions mentioned in a block may occur out of order. For example, two blocks illustrated consecutively may effectively occur substantially simultaneously, or they may often occur in reverse order according to the functions in question.

[0036] In this embodiment, the term "~part" refers to software or a hardware component such as an FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and "~part" takes on either role. However, this does not mean that "~part" is limited to software or hardware. "~part" may be configured to reside in an addressable storage medium, or may be configured to regenerate one or more processors. As an example, "~part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided by the components and "~part" may be combined into a smaller number of components and "~part," or further separated into additional components and "~part." Moreover, components and "~part" may be embodied to regenerate one or more CPUs (central processing units) within a device or security multimedia card. Furthermore, in the embodiment, the "~ section" may include one or more processors.

[0037] Wireless communication systems have evolved beyond providing early voice-centric services to broadband wireless communication systems that offer high-speed, high-quality packet data services, such as 3GPP®'s HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-A, LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

[0038] As a typical example of the aforementioned broadband wireless communication system, the LTE system employs the OFDM (Orthogonal Frequency Division Multiplexing) method for the downlink (DL) and the SC-FDMA (Single Carrier Frequency Division Multiple Access) method for the uplink (UL). The uplink refers to the radio link on which a terminal (UE (User Equipment) or MS (Mobile Station)) transmits data or control signals to a base station (eNode B or BS (base station)), while the downlink refers to the radio link on which a base station transmits data or control signals to a terminal. In such multiplexing methods, the data or control information of each user can usually be distinguished by allocating and operating the time-frequency resources for transmitting data or control information for each user in such a way that they do not overlap, i.e., orthogonality is maintained.

[0039] Post-LTE communication systems, i.e., 5G communication systems, must be able to freely reflect the diverse requirements of users and service providers, and services that can simultaneously satisfy these diverse requirements must be supported. Services to be considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low-latency communication (URLLC).

[0040] eMBB aims to provide data transmission speeds even higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a maximum transmission speed (peak data rate) of 20 Gbps on the downlink and a maximum transmission speed of 10 Gbps on the uplink from the perspective of a single base station. In addition, a 5G communication system must provide not only the maximum transmission speed but also an increased user-perceived data rate. Meeting these requirements necessitates improvements in various transmission and reception technologies, including more advanced Multi-Input Multi-Output (MIMO) transmission technology. Furthermore, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, a 5G communication system can meet the data transmission speed requirements by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or above frequency band.

[0041] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. mMTC requires features such as support for connecting large numbers of devices within a cell, improved device coverage, extended battery life, and reduced device costs to efficiently provide the Internet of Things. Since the Internet of Things provides communication functionality in conjunction with various sensors and devices, a large number of devices (e.g., 1,000,000 devices / km) are required within a cell. 2 It must be able to support mMTC. Also, terminals supporting mMTC are likely to be located in shaded areas where cells cannot cover, such as in the basements of buildings, due to the nature of the service, and may require wider coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must be low-cost terminals, and because it is difficult to replace the terminal's battery frequently, a very long battery life of 10 to 15 years may be required.

[0042] Finally, URLLC is a cellular-based wireless communication service used for specific purposes (mission-critical). Examples include services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC must offer extremely low latency and very high reliability. For example, services supporting URLLC must meet an air interface latency of less than 0.5 milliseconds and simultaneously handle 10 -5 The following packet error rate requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a smaller transmit time interval (TTI) compared to other services, and at the same time, design considerations may require allocating a wider range of resources in the frequency band to ensure the reliability of the communication link.

[0043] The three 5G services, namely eMBB, URLLC, and mMTC, may be multiplexed and transmitted within a single system. In this case, different transmission and reception techniques and parameters can be used between the services to satisfy the different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

[0044] [NR Time-Frequency Resources]

[0045] Figure 1 shows the basic structure in the time-frequency domain of a wireless communication system according to one embodiment of the present disclosure.

[0046] Referring to Figure 1, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. In the time and frequency domains, the basic unit of a resource is a Resource Element (RE, 101), which may be defined as 1 OFDM (Orthogonal Frequency Division Multiplexing) symbol 102 on the time axis and 1 subcarrier 103 on the frequency axis. In the frequency domain...

number

[0047] Figure 2 shows the frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0048] Referring to Figure 2, a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202) are shown. One frame (200) may be defined as 10ms. One subframe (201) may be defined as 1ms, and therefore, one frame (200) may consist of a total of 10 subframes (201). One slot (202, 203) may be defined as 14 OFDM symbols (i.e., the number of symbols per slot (

number

[0049] In an example shown in Figure 2, the cases where the subcarrier interval setting is μ=0 (204) and μ=1 (205) are shown. When μ=0 (204), one subframe 201 may consist of one slot 202, and when μ=1 (205), one subframe 201 may consist of two slots 203. In other words, the number of slots per subframe depends on the setting value μ for the subcarrier interval.

number

number

number

[0050] [Table 1]

[0051] [Bandwidth portion (BWP)]

[0052] Figure 3 shows the bandwidth setting in a wireless communication system according to one embodiment of the present disclosure.

[0053] Referring to Figure 3, an example is shown where the terminal bandwidth (UE bandwidth) 300 is configured as two bandwidth portions, namely, bandwidth portion #1 (BWP#1) 301 and bandwidth portion #2 (BWP#2) 302. A base station may configure one or more bandwidth portions for a terminal, and the information shown in Table 2 below can be configured for each bandwidth portion.

[0054] [Table 2]

[0055] Of course, the examples given above are not exhaustive, and various parameters related to bandwidth portions may be set on the terminal in addition to the configuration information described above. This information can be transmitted from the base station to the terminal by higher-layer signaling, such as RRC (Radio Resource Control) signaling. At least one of the configured bandwidth portions may be activated. Whether or not a configured bandwidth portion is activated may be transmitted quasi-statically from the base station to the terminal by RRC signaling, or dynamically by DCI (Downlink Control Information).

[0056] In some embodiments, before RRC (Radio Resource Control) connection, the terminal may have its initial bandwidth portion (Initial BWP) for initial connection configured by the base station using the MIB (Master Information Block). More specifically, at the initial connection stage, the terminal can use the MIB to receive configuration information for the control resource set (CORESET) and search space, from which a PDCCH for receiving the system information necessary for the initial connection (which may correspond to Remaining System Information; RMSI or System Information Block 1; SIB1) can be transmitted. The control resource set and search space configured in the MIB may each be considered as having identifier (Identity, ID) 0. The base station can use the MIB to notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for control resource set #0. The base station can also use the MIB to notify the terminal of configuration information for the monitoring period and occasion for control resource set #0, i.e., configuration information for search space #0. The terminal can consider the frequency domain set as control domain #0, obtained from the MIB, as the initial bandwidth portion for initial connection. In this case, the identifier (ID) of the initial bandwidth portion may be considered as 0.

[0057] The settings for the bandwidth portion supported by 5G may be used for various purposes.

[0058] When the bandwidth supported by the terminal is smaller than the system bandwidth, this can be compensated for by the bandwidth portion setting. For example, the base station sets the frequency position of the bandwidth portion (setting information 2) on the terminal, so that the terminal can send and receive data at a specific frequency position within the system bandwidth.

[0059] A base station can configure multiple bandwidth segments on a terminal to support different numerologies. For example, to support data transmission and reception using both a 15kHz and a 30kHz subcarrier interval on a terminal, two bandwidth segments can be configured, one for 15kHz and the other for 30kHz subcarrier intervals. Different bandwidth segments may be frequency-division multiplexed, and when attempting to transmit or receive data using a specific subcarrier interval, the bandwidth segment configured for that subcarrier interval may be activated.

[0060] Furthermore, according to some embodiments, a base station can configure a terminal with bandwidths of different sizes to reduce terminal power consumption. For example, if a terminal supports a very large bandwidth, such as 100 MHz, and constantly transmits and receives data using that bandwidth, very high power consumption may occur. In particular, monitoring unnecessary downlink control channels using a large 100 MHz bandwidth in the absence of traffic would be highly inefficient from a power consumption standpoint. To reduce terminal power consumption, a base station can configure a terminal with a relatively smaller bandwidth, such as 20 MHz. In the absence of traffic, the terminal can perform monitoring operations using the 20 MHz bandwidth, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth as instructed by the base station.

[0061] In the method for setting the bandwidth portion described above, a terminal before RRC connection can receive setting information for the initial bandwidth portion in the MIB (Master Information Block) during the initial connection stage. More specifically, the terminal can receive the setting of a control resource set (CORESET) for a downlink control channel from the PBCH (Physical Broadcast Channel) MIB, from which DCI (Downlink Control Information) scheduling SIBs (System Information Blocks) can be transmitted. The bandwidth of the control area in which the MIB is set may be considered the initial bandwidth portion, and the terminal can receive the PDSCH (Physical Downlink Shared Channel) on which SIBs are transmitted within the set initial bandwidth portion. In addition to receiving SIBs, the initial bandwidth portion may also be used for other system information (OSI), paging, and random access.

[0062] [Bandwidth portion (BWP) change]

[0063] When one or more bandwidth portions are configured on a terminal, the base station can instruct the terminal to change (or switch, transition) a bandwidth portion using the Bandwidth Part Indicator field in the DCI. For example, in Figure 3, if the currently active bandwidth portion of the terminal is bandwidth portion #(1301), the base station can instruct the terminal to use the Bandwidth Part Indicator in the DCI to use bandwidth portion #2(302), and the terminal can change its bandwidth portion to bandwidth portion #2(302) as indicated by the received Bandwidth Part Indicator in the DCI.

[0064] As mentioned above, DCI-based bandwidth portion changes may be instructed by the DCI scheduling the PDSCH or PUSCH. Therefore, when a terminal receives a bandwidth portion change request, it must be able to receive or transmit the PDSCH or PUSCH scheduled by that DCI without difficulty in the changed bandwidth portion. For this purpose, the standard requires a delay time (T) when a bandwidth portion change occurs. BWP This specifies the requirements for ), and may be defined, for example, as shown in Table 3.

[0065] [Table 3]

[0066] The requirements for bandwidth partial delay time support either Type 1 or Type 2, depending on the terminal's capability. The terminal can report to the base station the bandwidth partial delay time type it can support.

[0067] According to the aforementioned requirements for bandwidth portion change delay time, when a terminal receives a DCI containing a bandwidth portion change indicator in slot n, the terminal changes to the new bandwidth portion indicated by the bandwidth portion change indicator in slot n+T BWP The process can be completed at a time no later than the change in bandwidth portion, and transmission and reception can be performed on the data channel scheduled by the DCI using the new bandwidth portion. When the base station attempts to schedule a data channel to the new bandwidth portion, the terminal's bandwidth portion change delay time (T BWP The time domain resource allocation for a data channel can be determined by taking into consideration the bandwidth portion change delay time. In other words, when a base station schedules a data channel to a new bandwidth portion, the method of determining the time domain resource allocation for a data channel can be such that the data channel is scheduled after the bandwidth portion change delay time. As a result, the DCI that instructs the bandwidth portion change will be determined by the bandwidth portion change delay time (T BWP You do not need to expect to specify a slot offset (K0 or K2) value smaller than ).

[0068] If a terminal receives a DCI (e.g., DCI format 1_1 or 0_1) that instructs a partial bandwidth change, the terminal does not need to transmit or receive anything in the time interval from the third symbol of the slot that received the PDCCH containing the DCI to the start of the slot indicated by the slot offset (K0 or K2) value indicated in the time domain resource allocation indicator field within the DCI. For example, if a terminal receives a DCI instructing a partial bandwidth change in slot n, and the slot offset value indicated in the DCI is K, the terminal does not need to transmit or receive anything from the third symbol of slot n to the previous symbol of slot n+K (i.e., the last symbol of slot n+K-1).

[0069] [SS / PBCH block]

[0070] An SS / PBCH block can refer to a physical layer channel block composed of PSS (Primary SS), SSS (Secondary SS), and PBCH.

[0071] - PSS: A reference signal for downlink time / frequency synchronization, providing some information about the cell ID.

[0072] - SSS: Serves as the reference for downlink time / frequency synchronization and provides remaining cell ID information that PSS does not provide. Furthermore, it can serve as a reference signal for PBCH demodulation.

[0073] - PBCH: Provides system information necessary for sending and receiving data and control channels of a terminal. System information may include search space-related control information indicating radio resource mapping information for the control channel, scheduling control information for a separate data channel that transmits system information, etc.

[0074] - SS / PBCH block: An SS / PBCH block consists of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks may be transmitted within a 5ms time, and each transmitted SS / PBCH block may be distinguished by an index.

[0075] The terminal can detect PSS and SSS during the initial connection phase and decode PBCH. It can obtain an MIB from the PBCH and receive the settings for Control Resource Set (CORESET) #0 (which may correspond to a control area with a CORESET index of 0) from this MIB. The terminal can monitor CORESET #0, assuming that the DMRS (Demodulation Reference signal) transmitted in the selected SS / PBCH block and CORESET #0 is QCL (Quasi Co Location). The terminal can receive system information from the downlink control information transmitted in CORESET #0. From the received system information, the terminal can obtain the RACH (Random Access Channel) related setting information necessary for the initial connection. The terminal can send a PRACH (Physical RACH) to the base station, taking into account the selected SS / PBCH index, and the base station that receives the PRACH can obtain information about the SS / PBCH block index selected by the terminal. The base station can see which block the terminal selected from among the SS / PBCH blocks and that it is monitoring the associated CORESET #0.

[0076] [PDCCH: DCI related]

[0077] In a 5G system, scheduling information for uplink data (or Physical Uplink Shared Channel, PUSCH) or downlink data (or Physical Downlink Shared Channel, PDSCH) is transmitted from the base station to the terminal via DCI. The terminal can monitor the DCI format for fallback and the DCI format for non-fallback for PUSCH or PDSCH. The fallback DCI format may include predefined fixed fields between the base station and the terminal, while the non-fallback DCI format may include configurable fields.

[0078] DCI messages may be transmitted over the Physical Downlink Control Channel (PDCCH) after channel coding and modulation. A Cyclic Redundancy Check (CRC) is added to the DCI message payload, and the CRC may be scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, such as terminal-specific data transmission, power control commands, or random access responses. That is, the RNTI is not explicitly transmitted but is included in the CRC calculation process. When a terminal receives a DCI message transmitted over the PDCCH, it checks the CRC using its assigned RNTI, and if the CRC check is correct, the terminal knows that the message was sent to it.

[0079] For example, a DCI that schedules a PDSCH for System Information (SI) may be scrambled with SI-RNTI. A DCI that schedules a PDSCH for RAR (Random Access Response) messages may be scrambled with RA-RNTI. A DCI that schedules a PDSCH for Paging messages may be scrambled with P-RNTI. A DCI that notifies SFI (Slot Format Indicator) may be scrambled with SFI-RNTI. A DCI that notifies TPC (Transmit Power Control) may be scrambled with TPC-RNTI. A DCI that schedules a terminal-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

[0080] DCI format 0_0 may be used for a contingency DCI to schedule a PUSCH, in which case the CRC may be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI may include, for example, the information in Table 4.

[0081] [Table 4]

[0082] DCI format 0_1 ​​may be used for non-preparatory DCIs that schedule PUSCH, in which case the CRC may be scrambled with C-RNTI. DCI format 0_1 ​​with CRC scrambled with C-RNTI may include, for example, the information in Table 5.

[0083] [Table 5A] [Table 5B]

[0084] DCI format 1_0 may be used as a contingency DCI for scheduling PDSCH, in which case the CRC may be scrambled with C-RNTI. DCI format 1_0 with CRC scrambled with C-RNTI may include, for example, the information in Table 6.

[0085] [Table 6]

[0086] DCI format 1_1 may be used for non-preparatory DCIs that schedule PDSCH, in which case the CRC may be scrambled with C-RNTI. DCI format 1_1 with CRC scrambled with C-RNTI may include, for example, the information in Table 7.

[0087] [Table 7]

[0088] [PDCCH:CORESET, REG, CCE, Search Space]

[0089] Figure 4 shows the setting of the control area for the downlink control channel in a wireless communication system according to one embodiment of the present disclosure. Specifically, Figure 4 shows an example of the control area (Control Resource Set, CORESET) to which the downlink control channel is transmitted in a 5G wireless communication system.

[0090] Referring to Figure 4, in the frequency axis, the terminal bandwidth portion (UE bandwidth part) 410 is set, and in the time axis, two control areas (control area #1 401, control area #2 402) are set within one slot 420. Control areas 401 and 402 may be set within a specific frequency resource 403 within the overall terminal bandwidth portion 410 in the frequency axis. In the time axis, they may be set as one or more OFDM symbols, which can be defined as the control area length (Control Resource Set Duration, 404).

[0091] Control area #1 401 is set to have a control area length of 2 symbols, and control area #2 402 is set to have a control area length of 1 symbol.

[0092] In the aforementioned 5G, the control area may be set by the base station on the terminal using higher-layer signaling (e.g., System Information, MIB (Master Information Block), RRC (Radio Resource Control) signaling). Setting a control area on the terminal means providing information such as the control area identifier (Identity), the frequency position of the control area, and the symbol length of the control area. For example, this may include the information in Table 8.

[0093] [Table 8]

[0094] In Table 8, the tci-StatesPDCCH (abbreviated as TCI (Transmission Configuration Indication) state) setting information may include information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co-located) relationship with the DMRS transmitted in the corresponding control area.

[0095] Figure 5 shows a downlink control channel in a wireless communication system according to one embodiment of the present disclosure. More specifically, Figure 5 shows an example of the basic units of time and frequency resources that constitute a downlink control channel usable in 5G.

[0096] Referring to Figure 5, the basic unit of time and frequency resources constituting a control channel may be a REG (Resource Element Group, 503), and a REG 503 may be defined as 1 OFDM symbol 501 on the time axis and 1 PRB (Physical Resource Block, 502) on the frequency axis, i.e., 12 subcarriers. A base station can connect REG 503s to form a downlink control channel allocation unit.

[0097] As shown in Figure 5, if the basic unit to which a downlink control channel is assigned in 5G is a CCE (Control Channel Element, 504), then one CCE 504 may consist of multiple REGs 503. For example, a REG 503 may consist of 12 REs, and if one CCE 504 consists of 6 REGs 503, then one CCE 504 may consist of 72 REs. When a downlink control area is established, the area may consist of multiple CCEs 504, and a specific downlink control channel may be mapped to one or more CCEs 504 and transmitted according to the aggregation level (AL) within the control area. The CCEs 504 within the control area are distinguished by numbers, and in this case, the numbers of the CCEs 504 may be given by a logical mapping scheme.

[0098] The basic unit of a downlink control channel, REG 503, shown in Figure 5, may include the entire region to which the DCI is mapped and the region to which the DMRS 505, a reference signal for decoding it, is mapped. Three DMRS 505s may be transmitted within one REG 503. The number of CCEs required to transmit a PDCCH may be 1, 2, 4, 8, or 16, depending on the Aggregation Level (AL), and different numbers of CCEs may be used to embody link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel may be transmitted with L CCEs. The terminal must detect the signal without knowing information about the downlink control channel, and for blind decoding, a search space representing the set of CCEs is defined. A search space is a set of downlink control channel candidates (CCEs) that a terminal should attempt to decode at a given integration level. Since there are various integration levels where one CCE set consists of 1, 2, 4, 8, or 16 CCEs, a terminal can have multiple search spaces. A search space set can be defined as the set of search spaces at all configured integration levels.

[0099] The search space may be classified into a common search space and an UE-specific search space. A certain group of terminals or all terminals can examine the common search space of PDCCH to receive cell-common control information such as dynamic scheduling and paging messages for system information. For example, PDSCH scheduling assignment information for SIB transmission, including cell operator information, can be received by examining the common search space of PDCCH. In the case of the common search space, a certain group of terminals or all terminals must receive PDCCH and may be defined as a set of already promised CCEs. Scheduling assignment information for UE-specific PDSCH or PUSCH may be received by examining the UE-specific search space of PDCCH. The UE-specific search space may be defined UE-specifically as a function of terminal identity and various system parameters.

[0100] In 5G, the parameters for the search space for PDCCH may be set from the base station to the terminal using higher-layer signaling (e.g., SIB, MIB, RRC signaling).

[0101] For example, a base station can configure the terminal with the number of PDCCH candidate groups at each integration level L, the monitoring period for the search space, the monitoring occasion for the search space at the symbol level within a slot, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the search space, and the control area index to be monitored in the search space. For example, this may include the information in Table 9.

[0102] [Table 9A] [Table 9B]

[0103] Depending on the configuration information, the base station can set one or more search space sets for a terminal. In some embodiments, the base station can set search space set 1 and search space set 2 for a terminal, and can configure search space set 1 to monitor DCI format A scrambled with X-RNTI in a common search space, and search space set 2 to monitor DCI format B scrambled with Y-RNTI in a terminal-specific search space.

[0104] According to the configuration information, there may be one or more search space sets in the common search space or the terminal-specific search space. For example, search space set #1 and search space set #2 may be set as the common search space, and search space set #3 and search space set #4 may be set as the terminal-specific search space.

[0105] In the common search space, the following combinations of DCI format and RNTI may be monitored. Of course, this is not limited to the examples below.

[0106] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0107] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0108] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0109] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0110] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0111] In the terminal identification search space, the following combinations of DCI format and RNTI may be monitored. Of course, this is not limited to the examples below.

[0112] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0113] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0114] The explicitly stated RNTI should follow the definition and usage described below.

[0115] C-RNTI (Cell RNTI): Terminal-specific PDSCH scheduling application

[0116] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling applications.

[0117] CS-RNTI (Configured Scheduling RNTI): A quasi-statically configured terminal-specific PDSCH scheduling application.

[0118] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling during the random access phase.

[0119] P-RNTI (Paging RNTI): Used for PDSCH scheduling where paging is sent.

[0120] SI-RNTI (System Information RNTI): Used for PDSCH scheduling where system information is transmitted.

[0121] INT-RNTI (Interruption RNTI): Used to indicate whether or not puncturing occurs in PDSCH.

[0122] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Application of power control command instructions to PUSCH.

[0123] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Application of power control command instructions for PUCCH.

[0124] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Application of power control command instructions to SRS.

[0125] The aforementioned specified DCI format should follow the definitions shown in the example in Table 10.

[0126] [Table 10]

[0127] In 5G, a search space with a control domain p and a search space set s, and an integration level L, can be expressed as shown in Equation 1 below.

[0128] [Formula 1]

[0129]

number

[0130] - L: Integrated level

[0131] - n CI Career Index

[0132] - N CCE,p : Total number of CCEs present within control region p

[0133]

number

[0134]

Number

[0135]

Number

[0136] - i = 0, …, L - 1

[0137]

Number

[0138] - n RNTI : Terminal identifier

[0139]

Number

[0140]

Number

[0141] In 5G, since a plurality of search space sets can be set with different parameters (for example, the parameters in Table 9), the set of search space sets monitored by the terminal at each time point may change. For example, if search space set #1 is set with an X-slot period, search space set #2 is set with a Y-slot period, and X and Y are different, the terminal can monitor both search space set #1 and search space set #2 in a specific slot, and can monitor one of search space set #1 and search space set #2 in a specific slot.

[0142] [PDCCH:BD / CCE Limit]

[0143] When multiple search space sets are configured on the terminal, the following conditions may be considered in determining which search space set the terminal must monitor.

[0144] If the terminal receives the setting r15monitoringcapability as the value of monitoringCapabilityConfig-r16, which is a higher-layer signaling, the terminal defines the maximum number of monitorable PDCCH candidate groups and the maximum number of CCEs that make up the overall search space (where the overall search space means the overall set of CCEs that corresponds to the union region of multiple sets of search spaces) for each slot. If the setting r16monitoringcapability is set as the value of monitoringCapabilityConfig-r16, the terminal defines the maximum number of monitorable PDCCH candidate groups and the maximum number of CCEs that make up the overall search space (where the overall search space means the overall set of CCEs that corresponds to the union region of multiple sets of search spaces) for each span.

[0145] [Condition 1: Maximum limit on the number of PDCCH candidate groups]

[0146] As described above, the maximum number of PDCCH candidate groups that the terminal can monitor is M, which is determined by the settings for upper-layer signaling. μ The subcarrier interval is 15.2 μ When defining a cell based on a slot and set to kHz, follow Table 11 below; when defining it based on a span, follow Table 12 below.

[0147] [Table 11]

[0148] [Table 12]

[0149] [Condition 2: Maximum CCE limit]

[0150] As described above, the maximum number of CCEs that make up the global search space (where the global search space refers to the entire set of CCEs corresponding to the union region of multiple sets of search spaces) is determined by the settings of the upper layer signaling. μ The subcarrier interval is 15.2 μ When defining a cell based on a slot and set to kHz, follow Table 13 below; when defining it based on a span, follow Table 14 below.

[0151] [Table 13]

[0152] [Table 14]

[0153] For the sake of explanation, we define the situation in which all of the above conditions 1 and 2 are met at a specific point in time as "Condition A". Therefore, a situation in which Condition A is not met means that at least one of the above conditions 1 or 2 is not met.

[0154] [PDCCH: Overbooking]

[0155] Depending on the base station's search space set configuration, it may occur that condition A is not met at a particular time. If condition A is not met at a particular time, the terminal can select and monitor only a portion of the search space sets configured to meet condition A at that time, and the base station can transmit PDCCH to the selected search space set.

[0156] The following methods can be used to select some of the search spaces from the overall set of search spaces.

[0157] If condition A for PDCCH cannot be met at a specific point in time (slot), the terminal (or base station) may, from among the search space sets existing at that time, preferentially select a search space set whose search space type is set to a common search space, over a search space set set to a terminal-specific search space.

[0158] If all search space sets designated as common search spaces have been selected (i.e., if condition A is still met after selecting all search spaces designated as common search spaces), then the terminal (or base station) can select a search space set designated as a terminal-specific search space. In this case, if there are multiple search space sets designated as terminal-specific search spaces, the search space set with a lower search space set index may have a relatively higher priority. Considering the priority, a terminal-specific search space set can be selected within the range that satisfies condition A.

[0159] [Rate Matching / Puncture Related]

[0160] The following sections will describe the rate matching and puncturing operations in detail.

[0161] When the time and frequency resource A, which attempts to transmit an arbitrary symbol sequence A, overlaps with an arbitrary time and frequency resource B, rate matching or puncturing operation may be considered as the transmit / receive operation of channel A, taking into account the overlapping region resource C of resource A and resource B.

[0162] Rate Matching Operation

[0163] - The base station can only map channel A to the remaining resource area of ​​the entire resource A that it intends to send symbol sequence A to the terminal, excluding resource C which overlaps with resource B. For example, if symbol sequence A consists of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the base station can sequentially map symbol sequence A to the remaining resources of resource A, excluding {resource #3} which corresponds to resource C, namely {resource #1, resource #2, resource #4}, and send it. As a result, the base station can map symbol sequence {symbol #1, symbol #2, symbol #3} to {resource #1, resource #2, resource #4} respectively and send it.

[0164] The terminal can determine resource A and resource B from the scheduling information for symbol sequence A from the base station, and from this, it can determine resource C, which is the overlapping area of ​​resource A and resource B. The terminal can receive symbol sequence A by assuming that it was mapped and transmitted using the remaining area of ​​the total resource A excluding resource C. For example, if symbol sequence A consists of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can receive symbol sequence A by assuming that it was sequentially mapped to {resource #1, resource #2, resource #4}, which are the remaining resources of resource A excluding {resource #3}, which corresponds to resource C. As a result, the terminal can perform a series of subsequent receiving operations by assuming that symbol sequence {symbol #1, symbol #2, symbol #3} was mapped and transmitted to {resource #1, resource #2, resource #4}, respectively.

[0165] Puncturing

[0166] When a base station attempts to transmit symbol sequence A to a terminal, if resource C exists within the entire resource A that overlaps with resource B, the base station maps symbol sequence A to the entire resource A. However, it does not transmit in the resource area corresponding to resource C, and can only transmit to the remaining resource area of ​​resource A excluding resource C. For example, if symbol sequence A consists of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the base station can map symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} to resource A {resource #1, resource #2, resource #3, resource #4}, and transmit only the symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to the remaining resources {resource #1, resource #2, resource #4}, excluding {resource #3} which corresponds to resource C, and does not need to transmit {symbol #3} which corresponds to resource C. As a result, the base station can map symbol sequence {symbol #1, symbol #2, symbol #4} to {resource #1, resource #2, resource #4} and transmit them.

[0167] The terminal can determine resource A and resource B from the scheduling information for symbol sequence A from the base station, and from this, it can determine resource C, which is the overlapping area of ​​resource A and resource B. The terminal can receive symbol sequence A assuming that it is mapped to the entire resource A, but was transmitted only in the remaining area of ​​resource A excluding resource C. For example, if symbol sequence A consists of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can assume that symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} is mapped to resource A {resource #1, resource #2, resource #3, resource #4}, but {symbol #3}, which corresponds to resource C, is not transmitted. The terminal can then assume that the symbol sequence {symbol #1, symbol #2, symbol #4}, which corresponds to the remaining resources of resource A excluding {resource #3} (which corresponds to resource C), has been mapped and transmitted, and receive accordingly. Consequently, the terminal can perform the subsequent series of receiving operations assuming that symbol sequence {symbol #1, symbol #2, symbol #4} has been mapped to {resource #1, resource #2, resource #4} and transmitted.

[0168] The following describes how to configure rate matching resources for the purpose of rate matching in 5G communication systems. Rate matching means that the size of a signal is adjusted considering the amount of resources available to transmit the signal. For example, rate matching for a data channel means that the data channel is not mapped and transmitted during specific time and frequency resource ranges, thereby adjusting the size of the data.

[0169] Figure 6 illustrates how base stations and terminals send and receive data while considering downlink data channels and rate matching resources.

[0170] Figure 6 shows the downlink data channel (PDSCH, 601) and rate matching resource 602. The base station can configure one or more rate matching resources 602 on the terminal by higher-layer signaling (e.g., RRC signaling). The configuration information for the rate matching resource 602 may include time-axis resource allocation information 603, frequency-axis resource allocation information 604, and period information 605. In the following, the bitmap corresponding to frequency-axis resource allocation information 604 will be named "first bitmap," the bitmap corresponding to time-axis resource allocation information 603 will be named "second bitmap," and the bitmap corresponding to period information 605 will be named "third bitmap." If all or part of the time and frequency resources of the scheduled data channel 601 overlap with a configured rate matching resource 602, the base station can rate match and transmit the data channel 601 using the portion of the rate matching resource 602, and the terminal can receive and decode after assuming that the data channel 601 has been rate matched using the portion of the rate matching resource 602.

[0171] The base station can, through additional settings, dynamically notify the terminal via DCI whether or not to perform rate matching on the data channel using the configured rate matching resource portion (corresponding to the "rate matching indicator" in the DCI format mentioned above). Specifically, the base station can select some of the configured rate matching resources and group them into rate matching resource groups, and can instruct the terminal via DCI using a bitmap method whether or not to perform rate matching on the data channel for each rate matching resource group. For example, if four rate matching resources, RMR#1, RMR#2, RMR#3, and RMR#4, are configured, the base station can configure rate matching groups RMG#1={RMR#1,RMR#2} and RMG#2={RMR#3,RMR#4}, and use two bits in the DCI field to instruct the terminal via a bitmap whether or not to perform rate matching on RMG#1 and RMG#2, respectively.

[0172] For example, you can specify "1" if rating matching should be performed, or "0" if rating matching should not be performed.

[0173] In 5G, the aforementioned rate matching resources are configured on the device using granularity, specifically "RB symbol level" and "RE level." More specifically, the following configuration methods may be used.

[0174] RB Symbol Level

[0175] The terminal can receive up to four RateMatchPattern settings for each bandwidth portion via upper-layer signaling, and one RateMatchPattern may include the following:

[0176] - Reserved resources within the bandwidth portion may include resources in which the time and frequency resource domains of said reserved resources are set on the frequency axis by a combination of RB-level bitmaps and symbol-level bitmaps. The reserved resources may be spanned across one or two slots. A periodicityAndPattern may be further set in which the time and frequency domains composed of each RB-level and symbol-level bitmap pair are repeated.

[0177] - The set of control resources within the bandwidth portion, the configured time and frequency domain resource areas, and the resource areas corresponding to the time domain pattern configured as the search space setting on which the resource areas are repeated may be included.

[0178] RE level

[0179] The device can receive the following settings via upper-layer signaling.

[0180] - Configuration information (lte-CRS-ToMatchAround) for REs corresponding to LTE CRS (Cell-specific Reference Signal or Common Reference Signal) patterns may include the number of LTE CRS ports (nrofCRS-Ports) and LTE-CRS-vshift(s) value (v-shift), the location information of the LTE carrier's center subcarrier (SubcarrierFreqDL) from a reference frequency point (e.g., reference point A), the LTE carrier's bandwidth size (carrierBandwidthDL), and subframe configuration information (mbsfn-SubframConfigList) corresponding to MBSFN (Multicast-broadcast single-frequency network). Based on the aforementioned information, the terminal can determine the position of the CRS within the NR slot corresponding to the LTE subframe.

[0181] - May include configuration information for resource sets corresponding to one or more ZP (Zero Power) CSI-RS within the bandwidth portion.

[0182] [LTE CRS Rate Matching Related]

[0183] For LTE-NR coexistence, NR provides a function to set the LTE CRS (Cell Specific Reference Signal) pattern on NR terminals. More specifically, the CRS pattern may be provided by RRC signaling that includes at least one parameter in the ServingCellConfig IE (Information Element) or ServingCellConfigCommon IE. Examples of such parameters include lte-CRS-ToMatchAround, lte-CRS-PatternList1-r16, lte-CRS-PatternList2-r16, crs-RateMatch-PerCORESETPoolIndex-r16, etc.

[0184] Rel-15NR provides a function that allows one CRS pattern to be set per serving cell using the lte-CRS-ToMatchAround parameter. In Rel-16NR, this function is extended to allow multiple CRS patterns to be set per serving cell. More specifically, a Single-TRP (transmission and reception point) configured terminal may have one CRS pattern set per LTE carrier, while a Multi-TRP configured terminal can have two CRS patterns set per LTE carrier. For example, a Single-TRP configured terminal can have up to three CRS patterns set per serving cell using the lte-CRS-PatternList1-r16 parameter.

[0185] As another example, a multi-TRP configured terminal may have a CRS set for each TRP. That is, the CRS pattern for TRP1 may be set by the lte-CRS-PatternList1-r16 parameter, and the CRS pattern for TRP2 may be set by the lte-CRS-PatternList2-r16 parameter. When two TRPs are configured in this way, whether to apply all of the CRS patterns of TRP1 and TRP2 to a specific PDSCH (Physical Downlink Shared Channel), or only the CRS pattern of one TRP, is determined by the crs-RateMatch-PerCORESETPoolIndex-r16 parameter. If the crs-RateMatch-PerCORESETPoolIndex-r16 parameter is set to enabled, only the CRS pattern of one TRP will be applied; otherwise, both TRP CRS patterns will be applied.

[0186] Table 15 shows a ServingCellConfig IE including the CRS pattern, and Table 16 shows a RateMatchPatternLTE-CRS IE including at least one parameter for the CRS pattern.

[0187] [Table 15A] [Table 15B] [Table 15C]

[0188] [Table 16]

[0189] [PDSCH: Frequency Resource Allocation Related]

[0190] Figure 7 shows the frequency axis resource allocation of a PDSCH (physical downlink shared channel) in a wireless communication system according to one embodiment of the present disclosure. More specifically, Figure 7 shows three frequency axis resource allocation methods that can be set by the upper layer in an NR wireless communication system: type 0 (7-00), type 1 (7-05), and dynamic switch (7-10).

[0191] Referring to Figure 7, if a terminal is configured to use only resource type 0 by upper-layer signaling (7-00), some of the downlink control information (DCI) that assigns a PDSCH to that terminal includes a bitmap consisting of NRBG (number of resource block group) bits. NRBG refers to the number of RBG (resource block group) determined by the BWP size assigned by the BWP indicator and the upper-layer parameter rbg-Size, as shown in Table 17 below, and data is transmitted with RBGs that are displayed as 1 in the bitmap.

[0192] [Table 17]

[0193] If, for example, a terminal is configured to use only resource type 1 through upper-layer signaling (7-05), some DCIs that assign a PDSCH to that terminal will

number

[0194] If a terminal is configured to use both resource type 0 and resource type 1 by upper-layer signaling (7-10), some DCIs that assign a PDSCH to the terminal include frequency axis resource allocation information consisting of the larger bit value (7-35) of the payload for setting resource type 0 (7-15) and the payloads 7-20 and 7-25 for setting resource type 1. In this case, one bit may be added to the beginning of the frequency axis resource allocation information in the DCI (i.e., MSB), and if the value of this bit is "0", it indicates that resource type 0 should be used, and if the value is "1", it indicates that resource type 1 should be used.

[0195] [PDSCH / PUSCH: Related to time resource allocation]

[0196] The following describes how time-domain resources are allocated to data channels in next-generation mobile communication systems (5G or NR systems).

[0197] A base station can configure tables for time-domain resource allocation information for downlink data channels (Physical Downlink Shared Channel, PDSCH) and uplink data channels (Physical Uplink Shared Channel, PUSCH) on terminals using upper-layer signaling (e.g., RRC signaling). For PDSCH, a table consisting of a maximum of maxNrofDL-Allocations=16 entries may be configured, and for PUSCH, a table consisting of a maximum of maxNrofUL-Allocations=16 entries may be configured. In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to the time interval in slot units between the time a PDCCH is received and the time a PDSCH scheduled by the received PDCCH is transmitted; denoted by K0), PDCCH-to-PUSCH slot timing (corresponding to the time interval in slot units between the time a PDCCH is received and the time a PUSCH scheduled by the received PDCCH is transmitted; denoted by K2), information regarding the position and length of the start symbol in which a PDSCH or PUSCH is scheduled within the slot, and the mapping type of the PDSCH or PUSCH. For example, information like that shown in Table 18 or Table 19 below may be transmitted from the base station to the terminal.

[0198] [Table 18]

[0199] [Table 19]

[0200] The base station can notify a terminal of one of the entries in the table for the above-described time-domain resource allocation information using L1 (layer 1) signaling (e.g., DCI) (e.g., it may be indicated in the "time-domain resource allocation" field in DCI). The terminal can obtain the time-domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

[0201] FIG. 8 shows the time-axis resource allocation of PDSCH in a wireless communication system according to an embodiment of the present disclosure.

[0202] Referring to FIG. 8, the base station can indicate the time-axis position of the PDSCH resource by the subcarrier spacing (SCS) (μ PDSCH , μ PDCCH ) of the data channel and the control channel set using the upper layer, the scheduling offset (K0) value, and the OFDM symbol start position 8-00 and length 8-05 within one slot dynamically indicated by DCI.

[0203] FIG. 9 is a diagram showing the time-axis resource allocation according to the subcarrier spacing of the data channel and the control channel in a wireless communication system according to an embodiment of the present disclosure.

[0204] Referring to FIG. 9, when the subcarrier spacing of the data channel and the control channel is the same 9-00 (μ PDSCH = μ PDCCH ), since the slot numbers for data and control are the same, the base station and the terminal can generate the scheduling offset by a predetermined slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel is different 9-05 (μ PDSCH ≠ μPDCCH ) Since the slot numbers for data and control are different, the base station and the terminal can generate a scheduling offset by a predetermined slot offset K0 based on the subcarrier spacing of the PDCCH.

[0205] [PUSCH: Related to Transmission Mode]

[0206] PUSCH transmission may be dynamically scheduled by a UL grant in DCI or may operate according to configured grant Type 1 or Type 2. The dynamic scheduling instruction for PUSCH transmission is possible with DCI format 0_0 or 0_1.

[0207] Configured grant Type 1 PUSCH transmissions may be quasi-statically configured by receiving a configuredGrantConfig, including the rrc-ConfiguredUplinkGrant in Table 20, using higher-level signaling, without receiving a UL grant within the DCI. Configured grant Type 2 PUSCH transmissions may be semi-persistently scheduled by a UL grant within the DCI after receiving a configuredGrantConfig, which does not include the rrc-ConfiguredUplinkGrant in Table 20, using higher-level signaling. When a PUSCH transmission operates via a configured grant, the parameters applied to the PUSCH transmission are those of the configuredGrantConfig, which is the higher-level signaling in Table 20, with the exception of dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH, which are provided as push-Config in Table 21, which is the higher-level signaling. When a terminal receives a transformPrecoder in configuredGrantConfig, which is the higher-level signaling in Table 20, the terminal applies tp-pi2BPSK in push-Config in Table 21 to the PUSCH transmission that is operated by configured grant.

[0208] [Table 20A] [Table 20B]

[0209] The DMRS antenna port for PUSCH transmission may be the same as the antenna port for SRS transmission. PUSCH transmission should follow either a codebook-based transmission method or a non-codebook-based transmission method, depending on whether the value of txConfig in push-Config in Table 21, which is the higher-level signaling, is "codebook" or "nonCodebook".

[0210] As described above, PUSCH transmissions may be dynamically scheduled by DCI format 0_0 or 0_1, or quasi-statically configured by configured grant. If a terminal receives a scheduling instruction for a PUSCH transmission in DCI format 0_0, it will configure the beam for the PUSCH transmission using the push-spatialRelationInfoID corresponding to the terminal-specific PUCCH resource corresponding to the minimum ID within the activated uplink BWP in the serving cell, in which case the PUSCH transmission is single-antenna port based. The terminal does not expect scheduling for PUSCH transmissions in DCI format 0_0 within a BWP where a PUCCH resource containing push-spatialRelationInfo is not configured. If the terminal does not receive the txConfig setting in push-Config in Table 21, it does not expect to be scheduled in DCI format 0_1.

[0211] [Table 21]

[0212] Codebook-based PUSCH transmissions may be dynamically scheduled by DCI format 0_0 or 0_1, or they may operate quasi-statically by configured grant. When a Codebook-based PUSCH is dynamically scheduled by DCI format 0_1 ​​or quasi-statically configured by configured grant, the terminal determines the precoder for the PUSCH transmission based on the SRI (SRS Resource Indicator), TPMI (Transmission Precoding Matrix Indicator), and transmission rank (number of PUSCH transmission layers).

[0213] The SRI may be provided in the SRI field within the DCI, or set in the higher-level signaling srs-ResourceIndicator. A terminal may have at least one SRS resource configured during a codebook-based PUSCH transmission, and may have up to two. When a terminal receives an SRI in the DCI, the SRS resource indicated by that SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH containing that SRI. The TPMI and transmission rank may be provided in the precoding information and number of layers field within the DCI, or set in the higher-level signaling precodingAndNumberOfLayers. The TPMI may be used to indicate the precoder to be applied to the PUSCH transmission. If a terminal receives the configuration of one SRS resource, the TPMI is used to indicate the precoder to be applied to that configured SRS resource. If a terminal receives settings for multiple SRS resources, TPMI is used to specify the precoder to be applied to the SRS resource indicated by the SRI.

[0214] The precoder used for PUSCH transmission is selected from an uplink codebook that has the same number of antenna ports as the nrofSRS-Ports value in the higher-level signaling, SRS-Config.

[0215] In Codebook-based PUSCH transmission, the terminal determines the codebook subset based on TPMI and the codebookSubset in the higher-level signaling push-Config. The codebookSubset in the higher-level signaling push-Config may be set to one of "fullyAndPartialAndNonCoherent", "partialAndNonCoherent", or "nonCoherent" based on the UE capability that the terminal reports to the base station.

[0216] If a terminal reports "partialAndNonCoherent" as its UE capability, it does not expect the value of the higher-level signaling, codebookSubset, to be set to "fullyAndPartialAndNonCoherent". Similarly, if a terminal reports "nonCoherent" as its UE capability, it does not expect the value of the higher-level signaling, codebookSubset, to be set to either "fullyAndPartialAndNonCoherent" or "partialAndNonCoherent". If nrofSRS-Ports in the higher-level signaling, SRS-ResourceSet, indicates two SRS antenna ports, the terminal does not expect the value of the higher-level signaling, codebookSubset, to be set to "partialAndNonCoherent".

[0217] The terminal may have one SRS resource set configured in the SRS-ResourceSet, which is the higher-level signaling, where the value of `usage` is set to "codebook". Within that SRS resource set, one SRS resource may be indicated by the SRI. If multiple SRS resources are configured within the SRS resource set, where the value of `usage` in the SRS-ResourceSet, which is the higher-level signaling, is set to "codebook", the terminal expects the value of `nrofSRS-Ports` in the SRS-Resource, which is the higher-level signaling, to be set to the same value for all SRS resources.

[0218] The terminal transmits one or more SRS resources contained within an SRS resource set with the usage value set to "codebook" via higher-level signaling to the base station. The base station selects one of the SRS resources transmitted by the terminal and instructs the terminal to perform a PUSCH transmission using the transmit beam information of that SRS resource. In a codebook-based PUSCH transmission, the SRI is used as information to select the index of one SRS resource and is included in the DCI. Furthermore, the base station includes information in the DCI indicating the TPMI and rank that the terminal will use for the PUSCH transmission. The terminal performs a PUSCH transmission using the SRS resource indicated by the SRI, applying the rank indicated based on the transmit beam of that SRS resource and the precoder indicated by the TPMI.

[0219] Non-codebook-based PUSCH transmissions may be dynamically scheduled by DCI format 0_0 or 0_1, or they may operate quasi-statically by configured grant. A terminal may schedule a non-codebook-based PUSCH transmission by DCI format 0_1 ​​if at least one SRS resource is configured in an SRS resource set where the usage value in the higher-level signaling SRS-ResourceSet is set to "nonCodebook".

[0220] For an SRS resource set where the usage value in the higher-level signaling SRS-ResourceSet is set to "nonCodebook", the terminal may have one linked NZP CSI-RS (non-zero power CSI-RS). The terminal can perform calculations for the precoder for SRS transmission by measuring the NZP CSI-RS resource linked to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource linked to the SRS resource set and the first symbol of the aperiodic SRS transmission at the terminal is less than 42 symbols, the terminal does not expect the information about the precoder for SRS transmission to be updated.

[0221] When the value of resourceType in the higher-level signaling SRS-ResourceSet is set to "aperiodic", the connected NZP CSI-RS is indicated by the SRS request field in DCI format 0_1 ​​or 1_1. In this case, if the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, the presence of the connected NZP CSI-RS is indicated if the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not "00". The DCI must not indicate cross-carrier or cross-BWP scheduling. Also, if the value of SRS request indicates the presence of an NZP CSI-RS, that NZP CSI-RS is located in the slot from which the PDCCH containing the SRS request field was transmitted. The TCI state set for the scheduled subcarrier is not set to QCL-TypeD.

[0222] If a periodic or semi-persistent SRS resource set is configured, the connected NZP CSI-RS may be indicated by the associated CSI-RS within the SRS-ResourceSet which is higher layer signaling. For non-codebook based transmission, the UE does not expect both the spatialRelationInfo which is higher layer signaling for the SRS resource and the associated CSI-RS within the SRS-ResourceSet which is higher layer signaling to be configured simultaneously.

[0223] When multiple SRS resources are configured for the UE, the precoder and transmission rank applied to the PUSCH transmission can be determined based on the SRI signaled by the base station. The SRI may be indicated by the SRS resource indicator field within the DCI, or may be configured by the srs-ResourceIndicator which is higher layer signaling. Similar to the codebook based PUSCH transmission described above, when the UE receives the SRI by DCI, the SRS resource indicated by the SRI means the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH containing the SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be transmitted simultaneously in the same symbol within one SRS resource set and the maximum number of SRS resources are determined by the UE capability reported by the UE to the base station. At this time, the SRS resources transmitted simultaneously by the UE occupy the same RB. The UE configures one SRS port for each SRS resource. Only one SRS resource set with the value of usage within the SRS-ResourceSet which is higher layer signaling set to "nonCodebook" may be configured, and up to 4 SRS resources for non-codebook based PUSCH transmission can be configured.

[0224] The base station transmits a single NZP-CSI-RS linked to an SRS resource set to the terminal. The terminal calculates a precoder to use when transmitting one or more SRS resources within the SRS resource set, based on the results measured upon receiving the NZP-CSI-RS. When the terminal transmits one or more SRS resources from an SRS resource set with usage set to "nonCodebook" to the base station, it applies the calculated precoder, and the base station selects one or more SRS resources from the received SRS resources. In this case, in a non-codebook-based PUSCH transmission, the SRI represents an index that can represent a combination of one or more SRS resources, and the SRI is included in the DCI. In this case, the number of SRS resources indicated by the SRI transmitted by the base station may be the number of transmission layers in PUSCH, and the terminal transmits PUSCH by applying the precoder applied to the SRS resource transmission to each layer.

[0225] [PUSCH: Preparation process time]

[0226] When a base station schedules a terminal to send a PUSCH using DCI format 0_0, 0_1, or 0_2, the terminal may need a PUSCH preparation time to apply the transmission method specified in DCI (transmission precoding method for SRS resources, number of transmission layers, spatial domain transmission filter) and send the PUSCH. NR takes this into consideration when defining the PUSCH preparation time. The terminal's PUSCH preparation time should follow [Equation 2] below.

[0227] [Formula 2]

[0228]

number

[0229] T in equation 2 proc,2 Each variable can have the following meanings:

[0230] - N2: The number of symbols determined by the terminal's capability, specifically its UE processing capability (UE processing capability) of 1 or 2, and its numerology μ. If the terminal's capability report indicates a UE processing capability of 1, it will have the value shown in Table 22. If it reports a UE processing capability of 2, and higher-layer signaling has enabled the use of UE processing capability 2, it may have the value shown in Table 23.

[0231] [Table 22]

[0232] [Table 23]

[0233] - d 2,1 The number of symbols determined to be 0 if the resource elements of the first OFDM symbols transmitted via PUSCH are all set to consist only of DM-RS symbols, and 1 otherwise.

[0234] - κ:64

[0235] - μ:μ DL or μ UL Of these, T proc,2 It follows the value that becomes larger. DL This refers to the numerology of the downlink to which a PDCCH is sent, which includes a DCI that schedules a PUSCH, and μ UL This refers to the numerology of the uplink from which PUSCH is transmitted.

[0236] - T c :1 / (Δf max *N f ), Δf max =480*103Hz, N f It has =4096

[0237] - d2,2 :If the DCI scheduling PUSCH instructs BWP switching, it will have the BWP switching time; otherwise, it will have 0.

[0238] - d2: When PUCCH, a PUSCH with a higher priority index, and an OFDM symbol of PUCCH with a lower priority index overlap in time, the d2 value of the PUSCH with the higher priority index is used. Otherwise, d2 is 0.

[0239] - T ext :When the terminal uses a shared spectral channel connection scheme, the terminal is T ext This can be calculated and applied to the PUSCH preparation time. Otherwise, T ext Assume that it is 0.

[0240] - T switch :When the uplink switching interval is triggered, T switch This is assumed to be the switching interval time. Otherwise, it is assumed to be 0.

[0241] When considering the time-axis resource mapping information of the PUSCH scheduled in DCI and the effects of the uplink-downlink timing advance, the base station and terminals start from the last symbol of the PDCCH that includes the DCI that scheduled the PUSCH. proc,2 If the first symbol of a PUSCH signal begins before the first uplink symbol that subsequently initiates a CP signal, the base station and terminal determine that there is insufficient PUSCH preparation time. Otherwise, the base station and terminal determine that there is sufficient PUSCH preparation time. The terminal will only transmit a PUSCH if there is sufficient PUSCH preparation time, and may ignore the DCI that schedules the PUSCH if there is insufficient preparation time.

[0242] [CA / DC related]

[0243] Figure 10 shows the wireless protocol structure of a base station and a terminal in a single cell environment, a carrier aggregation environment, and a dual connectivity environment according to one embodiment of the present disclosure.

[0244] Referring to Figure 10, the wireless protocol for the next-generation mobile communication system consists of NR SDAP (Service Data Adaptation Protocol S25, S70), NR PDCP (Packet Data Convergence Protocol S30, S65), NR RLC (Radio Link Control S35, S60), and NR MAC (Medium Access Control S40, S55) at the terminal and NR base station, respectively.

[0245] The main functions of NR SDAP (S25, S70) may include at least some of the following functions:

[0246] - User data transfer function

[0247] - Mapping function between a QoS flow and a DRB for both DL and UL links.

[0248] - QoS flow ID marking function for both uplink and downlink packets.

[0249] - A feature that maps reflective QoS flow to data bearers for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0250] The terminal may configure, via RRC messages, whether to use the SDAP layer device header or functions of the SDAP layer device for each PDCP layer device, bearer, or logical channel. If the SDAP header is configured, the terminal can instruct the NAS reflective QoS 1-bit indicator and AS reflective QoS 1-bit indicator of the SDAP header to update or reset the mapping information between the uplink and downlink QoS flow and data bearers. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used as data processing priority, scheduling information, etc., to support smooth service.

[0251] The main functions of NR PDCP (S30, S65) may include at least some of the following functions:

[0252] - Header compression and decompression function (ROHC only)

[0253] - User data transmission function

[0254] - Sequential delivery of upper layer PDUs

[0255] - Out-of-sequence delivery of upper layer PDUs

[0256] - Reordering function (PDCP PDU reordering for reception)

[0257] - Duplicate detection function (Duplicate detection of lower layer SDUs)

[0258] - Retransmission function (Retransmission of PDCP SDUs)

[0259] - Encryption and deciphering functions

[0260] - Timer-based SDU discard function (Timer-based SDU discard in uplink)

[0261] In the above, the reordering function of the NR PDCP device refers to the function of sequentially reordering PDCP PDUs received from lower layers based on the PDCP SN (sequence number), and may include a function of transmitting the data to higher layers in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function of immediately transmitting the data without considering the order, a function of recording PDCP PDUs lost due to the reordering, a function of reporting the status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs.

[0262] The main functions of NR RLC (S35, S60) may include at least some of the following functions:

[0263] - Data transmission function (Transfer of upper layer PDUs)

[0264] - Sequential delivery of upper layer PDUs

[0265] - Out-of-sequence delivery of upper layer PDUs

[0266] - ARQ function (Error Correction through ARQ)

[0267] - Concatenation, segmentation, and reassembly of RLC SDUs

[0268] - Re-segmentation function (RLC data PDUs)

[0269] - Reordering function (Reordering of RLC data PDUs)

[0270] - Duplicate detection function

[0271] - Error detection function (Protocol error detection)

[0272] - RLC SDU deletion function (RLC SDU discard)

[0273] - RLC re-establishment function

[0274] As described above, the in-sequence delivery function of an NR RLC device means the function of sequentially transmitting RLC SDUs received from lower layers to higher layers. The in-sequence delivery function of an NR RLC device may include a function to reassemble and transmit RLC SDUs when a single original RLC SDU is received divided into several RLC SDUs, a function to rearrange received RLC PDUs based on RLC SN (sequence number) or PDCP SN (sequence number), a function to record RLC PDUs lost due to the rearrangement of the sequence, a function to report the status of lost RLC PDUs to the transmitting side, and a function to request retransmission of lost RLC PDUs. The in-sequence delivery function of an NR RLC device may include a function that sequentially transmits only the RLC SDUs up to the point before the lost RLC SDU to the upper layer if there is a lost RLC SDU, or it may include a function that, even if there is a lost RLC SDU, transmits all RLC SDUs received before the timer was activated to the upper layer sequentially once a predetermined timer has expired.

[0275] Alternatively, the in-sequence delivery function of the NR RLC device may include a function that, even if there are lost RLC SDUs, sequentially transmits all RLC SDUs received up to the present to the upper layer once a predetermined timer has expired. Furthermore, the RLC PDUs can be processed in the order they are received (regardless of the order of the sequence number, in the order of arrival) and transmitted to the PDCP device in an out-of-sequence delivery manner. If they are segments, they can be stored in a buffer, and after receiving later segments, they can be reconstructed as a complete single RLC PDU, processed, and transmitted to the PDCP device. The NR RLC layer does not need to include a concatenation function; this function may be performed by the NR MAC layer, or replaced by the multiplexing function of the NR MAC layer.

[0276] As described above, the out-of-sequence delivery function of an NR RLC device refers to the function of immediately transmitting RLC SDUs received from lower layers to higher layers regardless of order. This may include a function to reassemble and transmit RLC SDUs when a single original RLC SDU is received split into several RLC SDUs, and may also include a function to save the RLC SN or PDCP SN of received RLC PDUs, sort them, and record any lost RLC PDUs.

[0277] The NR MAC (S40, S55) may be connected to multiple NR RLC layer devices configured in a single terminal, and the main functions of the NR MAC may include at least some of the following functions.

[0278] - Mapping function (Mapping between logical channels and transport channels)

[0279] - Multiplexing / demultiplexing of MAC SDUs

[0280] - Scheduling information reporting function

[0281] - HARQ function (Error correction through HARQ)

[0282] - Priority handling between logical channels of one UE (Logical User Interface)

[0283] - Priority handling between UEs by means of dynamic scheduling

[0284] - MBMS (Multimedia Broadcast Multicast Services) Service Identification Function

[0285] - Transport format selection function

[0286] - Padding function

[0287] The NR PHY layer (S45, S50) can perform the following operations: channel coding and modulation of upper layer data to create OFDM symbols and transmit them over the radio channel, or demodulating OFDM symbols received over the radio channel, channel decoding them, and transmitting them to the upper layer.

[0288] The aforementioned wireless protocol structure may be modified in various ways depending on the carrier (or cell) operating method. For example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure having a single structure for each layer, as shown in (S00). On the other hand, when a base station transmits data to a terminal based on carrier aggregation (CA) using multiple carriers with a single TRP, the base station and the terminal use a protocol structure having a single structure up to the RLC, as shown in (S10), but multiplexing the PHY layer through the MAC layer.

[0289] As another example, when a base station transmits data to a terminal based on DC (dual connectivity) using multiple carriers with multiple TRP, the base station and the terminal use a protocol structure that has a single structure up to the RLC, but multiplexes the PHY layer through the MAC layer, as shown in (S20).

[0290] Referring to the above-mentioned explanations regarding PDCCH and beam configuration, PDCCH repetitive transmission is not currently supported in Rel-15 and Rel-16NR, making it difficult to achieve the required reliability in scenarios requiring high reliability, such as URLLC. This disclosure provides a method for PDCCH repetitive transmission using multiple transmission points (TRPs) to improve the reliability of PDCCH reception at terminals. The specific method will be described in detail in the following embodiments.

[0291] The embodiments described herein are applicable to FDD and TDD systems. Upper-layer signaling (or upper-layer signaling) is a signal transmission method transmitted from a base station to a terminal using the downlink data channel of the physical layer, or from a terminal to a base station using the uplink data channel of the physical layer, and may be called RRC signaling, PDCP signaling, or MAC (medium access control) control element (MAC CE).

[0292] Hereinafter, when determining whether or not to apply cooperative communication in this disclosure, the terminal may use various methods, such as having a PDCCH to which a PDSCH to which cooperative communication is applied have a specific format, or having a PDCCH to which a PDSCH to which cooperative communication is applied include a specific indicator that shows whether or not cooperative communication is applied, or having a PDCCH to which a PDSCH to which cooperative communication is applied scrambled with a specific RNTI, or assuming the application of cooperative communication in a specific section indicated at a higher layer. Hereinafter, for the sake of explanation, the case in which a terminal receives a PDSCH to which cooperative communication is applied based on conditions similar to those described above will be referred to as the NC-JT (non-coherent joint transmission) case.

[0293] Determining the priority between A and B can be expressed in various ways, such as selecting the one with a relatively higher priority according to a predetermined priority rule and performing the corresponding action, or omitting or dropping the action for the one with a relatively lower priority.

[0294] In the following disclosure, the above examples will be explained using numerous embodiments, but these embodiments are not necessarily independent, and it is possible to apply one or more embodiments simultaneously or in combination.

[0295] The upper-level signaling may be at least one or a combination of the following signalings.

[0296] - MIB(Master Information Block)

[0297] - SIB (System Information Block) or SIB X (X=1,2,…)

[0298] - RRC (Radio Resource Control)

[0299] - MAC(Medium Access Control)CE(Control Element)

[0300] Furthermore, L1 signaling may be a signaling method that corresponds to at least one or a combination of the following physical layer channels or signaling methods.

[0301] - PDCCH(Physical Downlink Control Channel)

[0302] - DCI(Downlink Control Information)

[0303] - UE-specific DCI

[0304] - Group common DCI

[0305] - Common DCI

[0306] - Scheduling DCI (e.g., DCI used for scheduling downlink or uplink data)

[0307] - Non-scheduling DCI (e.g., DCI not intended to schedule downlink or uplink data)

[0308] - PUCCH(Physical Uplink Control Channel)

[0309] - UCI(Uplink Control Information)

[0310] This disclosure provides a method for rate-matching PDSCH and a method for PUCCH resource determination by monitoring PDCCH repetition transmissions when PDCCH repetition transmission is configured on a terminal.

[0311] A base station can repeatedly transmit a PDCCH to provide a higher PDCCH reception confidence level to a terminal. Hereinafter, the repeatedly transmitted PDCCH may contain the same DCI. For the sake of explanation, the repeated transmission of the PDCCH will be referred to as PDCCH repeat transmission. For PDCCH repeat transmission, the base station can set at least one of the following pieces of information (e.g., first information, second information, third information, etc.) on the terminal.

[0312] In the first piece of information, the base station can set up two or more search spaces for the terminal. The terminal can monitor (or receive) PDCCH using blind decoding in the search spaces. Each of the search spaces may be separated by a unique and distinct index (or ID (identity)). Each search space setting may include at least one of the following pieces of information.

[0313] The search space configuration may include information about the CORESET to which the search space belongs. For example, each search space may belong to the same CORESET, or they may belong to different CORESETs.

[0314] The search space configuration may include information about the number of PDCCH candidates at each aggregation level in the search space. Here, at least 1, 2, 4, 8, and 16 aggregation levels may be supported.

[0315] The search space setting may include information about symbols (i.e., time) for PDCCH monitoring occasions (PDCCH MOs). This information may include a period and offset per slot, and information about the symbol in which a PDCCH monitoring occasion begins within a slot. Here, the information about the symbol in which a PDCCH monitoring occasion begins within a slot can be represented by a bitmap (e.g., 14 bits), where the Nth bit of the bitmap indicates whether a PDCCH monitoring occasion begins at the Nth OFDM symbol in the slot. If the Nth bit of the bitmap is "1", then a PDCCH monitoring occasion begins at the Nth OFDM symbol in the slot. If the Nth bit of the bitmap is "0", then a PDCCH monitoring occasion does not begin at the Nth OFDM symbol in the slot.

[0316] In the second piece of information, the base station can set up two or more search spaces in which PDCCH is repeatedly transmitted to the terminal. The base station can set up the two or more search spaces in which PDCCH is repeatedly transmitted to the terminal using the index (or ID (identity)) of the two or more search spaces in which PDCCH is repeatedly transmitted. Here, the search spaces in which PDCCH is repeatedly transmitted can be said to be linked to each other. For reference, the two linked search spaces may have the same aggregation level (e.g., 1, 2, 4, 8, 16) and the same number of PDCCH candidates per aggregation level.

[0317] More specifically, the second piece of information may be set by one of the following two methods:

[0318] First configuration method: A base station can configure a search space group for PDCCH repetitive transmission, and the search space group may include at least two search spaces. The search space group may be distinguished by a unique index (or ID (identity)). The search spaces included in the search space group may be configured by a search space-specific index (or ID (identity)). For example, a base station can configure search space group 1 for PDCCH repetitive transmission, and to include search space 1 and search space 2 in search space group 1, it can configure the terminal with the index (or ID (identity)) {1,2} of each search space. In other words, the index (or ID (identity)) {1,2} of the search spaces may be configured in correspondence with the index (or ID (identity)) of search space group 1.

[0319] Second configuration method: When a base station configures each search space for PDCCH repeat transmission, it can configure the index (or ID) of each search space and the search spaces linked to it. For example, when configuring search space 1 to link search space 1 and search space 2, the base station may include information indicating that search space 2 is linked to the configuration of search space 1. Similarly, when configuring search space 2, the base station may include information indicating that search space 1 is linked to the configuration of search space 2. As an example, the "information indicating that it is linked" may be the index (or ID (identity)) of the linked search space. Furthermore, when configuring each search space, a unique index (or ID (identity)) can be set for the group of search spaces composed of that search space or the linked search spaces.

[0320] In the above example, when setting up search space 1, the settings may include information indicating that search space 2 is linked to the setting up search space 1 (e.g., the index of search space 2) and information indicating that search space 1 and search space 2 are included in search space group 1 (e.g., the index of search space group 1). Similarly, when setting up search space 2, the base station may include information indicating that search space 1 is linked to the setting up search space 2 (e.g., the index of search space 1) and information indicating that search space 2 and search space 1 are included in search space group 1 (e.g., the index of search space group 1). The "information indicating that they are included in a search space group" may be the unique index (or ID (identity)) of the search space group.

[0321] As described above, the two linked search spaces may have the same aggregation level (e.g., 1, 2, 4, 8, 16) and the same number of PDCCH candidates per aggregation level. It can be assumed that the terminal sends the same DCI for the same index PDCCH candidate corresponding to the same aggregation level (e.g., 1, 2, 4, 8, 16) in both search spaces. As a concrete example, the linked search spaces can be assumed to be search space 1 and search space 2. In search space 1 and search space 2, it can be assumed that there are two PDCCH candidates at aggregation level 4 (index=0 and index=1) and one PDCCH candidate at aggregation level 8 (index=0). In this case, the same DCI may be transmitted at the first PDCCH candidate (index=0) where the integration level of search space 1 and search space 2 is 4, the same DCI may be transmitted at the second PDCCH candidate (index=1) where the integration level of search space 1 and search space 2 is 4, and the same DCI may be transmitted at the PDCCH candidate (index=0) where the integration level of search space 1 and search space 2 is 8. Therefore, the terminal can receive the same DCI at each PDCCH candidate in each search space based on the configuration information of the linked search spaces (same integration level (e.g., 1, 2, 4, 8, 16) and the same number of PDCCH candidates per integration level).

[0322] In the following explanation, we can assume that PDCCH candidates corresponding to the same index at the same integration level (e.g., 1, 2, 4, 8, 16) in two search spaces are linked. In the above example, the first PDCCH candidate (index=0) with integration level 4 in search space 1 is linked to the first PDCCH candidate (index=0) with integration level 4 in search space 2; the second PDCCH candidate (index=1) with integration level 4 in search space 1 is linked to the second PDCCH candidate (index=1) with integration level 4 in search space 2; and the first PDCCH candidate (index=0) with integration level 8 in search space 1 is linked to the first PDCCH candidate (index=0) with integration level 8 in search space 2.

[0323] When a base station links two or more search spaces, the base station must always transmit the same DCI at the PDCCH candidates of the linked search spaces. That is, when the base station transmits a first DCI at the linked PDCCH candidates of some of the linked search spaces and a second DCI at the linked PDCCH candidates of some of the other linked search spaces, the first DCI and the second DCI must not be different. From the terminal's perspective, when two or more search spaces are linked, the terminal can always expect that the same DCI will be transmitted at the linked PDCCH candidates of the linked search spaces. That is, when the terminal receives a first DCI at the linked PDCCH candidates of some of the linked search spaces and a second DCI at the linked PDCCH candidates of some of the other linked search spaces, the terminal can expect that the first DCI and the second DCI are not different. In other words, if the first DCI and the second DCI are different, the terminal can determine it to be an error case.

[0324] Under the above assumptions of base station and terminal operation, the terminal can receive linked PDCCH candidates in a linked search space where the same DCI is transmitted in the following manner:

[0325] As a first receiving method, the terminal can independently or separately receive PDCCH candidates in some or one of the linked search spaces. That is, even if the terminal is configured to repeatedly transmit the same DCI in linked PDCCH candidates within the linked search spaces, the terminal can receive the DCI by blind decoding the PDCCH candidates in some or one of the search spaces. In this case, when blind decoding PDCCH candidates in some or one of the search spaces, linked PDCCH candidates in other linked search spaces are not considered, and only the PDCCH candidates in the said some or one of the search spaces may be used. Since blind decoding is performed separately for some or one of the search spaces in this way, it can be expressed as independent or separate. For convenience, this method is called separate PDCCH decoding.

[0326] In individual PDCCH decoding, terminals may have multiple opportunities to receive a PDCCH using different search spaces, and the probability of successful PDCCH reception may increase if these multiple PDCCH reception opportunities pass through different channel environments. For example, if the channel environment of some of the linked search spaces is poor (for example, if the TRP transmitted in that search space is blocked due to high interference in the bandwidth / time it is transmitted, resulting in a low received SNR), the PDCCH can be successfully received in one of the remaining search spaces with a good channel environment. In general, individual PDCCH decoding may be suitable when transmitting linked search spaces in different channel environments.

[0327] As a second receiving method, the terminal can cooperatively or jointly receive linked PDCCH candidates in the linked search space. That is, since the terminal is configured to repeatedly transmit the same DCI for linked PDCCH candidates in the linked search space, it can receive the DCI by soft-combining the decision values ​​(e.g., LLR (log-likelihood ratio) value or a similar decision value used in the decoding process) of the linked PDCCH candidates in the linked search space and performing blind decoding. In this case, since the terminal performs blind decoding using all linked PDCCH candidates in the linked search space, it can be described as cooperative or joint. For convenience, this method is called joint PDCCH decoding. For reference, since the base station always repeatedly transmits the same DCI for linked PDCCH candidates in the linked search space, the terminal can perform joint PDCCH decoding. Joint PDCCH decoding allows the terminal to receive the same DCI multiple times, thus providing not only the gain from the different channel environments offered by individual PDCCH decoding, but also the SNR gain (or channel code gain) from multiple iterations.

[0328] A terminal can perform PDCCH blind decoding by selectively using one of the following methods: individual PDCCH decoding (e.g., first receiving method) or joint PDCCH decoding (e.g., second receiving method). Alternatively, a terminal can perform PDCCH blind decoding using both individual and joint PDCCH decoding. This is determined by the implementation of the terminal, and therefore, the base station cannot force the terminal to perform PDCCH blind decoding using a specific method or to use both methods. In other words, the base station configures that the same DCI is repeatedly transmitted for linked PDCCH candidates in the linked search space, but the terminal can perform PDCCH blind decoding using part or all of the linked search space, and the base station may not know which PDCCH blind decoding method the terminal is using.

[0329] This disclosure aims to resolve misunderstandings between base stations and terminals that arise due to the ambiguity of the PDCCH blind decoding method used by terminals.

[0330] In this disclosure, the operation of the terminal is described in a situation where two search spaces (for example, search space 1 and search space 2) are linked, but this may be extended to a situation where two or more search spaces are linked.

[0331] <First Embodiment: PDSCH Rate Matching Method Based on the Availability of PDCCH Reception (Monitoring)>

[0332] Figure 11 shows an example of PDSCH rate matching considering the possibility of PDCCH reception according to one embodiment of the present disclosure.

[0333] Referring to Figure 11, when a base station-terminal transmits and receives a PDSCH, the resource from which the PDCCH is transmitted (or received) can be assumed to be a resource unavailable for the PDSCH. Here, the resource of the received PDCCH may include linked PDCCH candidates. For example, in Figure 11, the terminal can receive a setting that Search space 1 1100 and Search space 2 1105 are linked, and that PDCCH candidate 1110, which is integration level 16 of Search space 1 1100, and PDCCH candidate 1115, which is integration level 16 of Search space 2 1105, are linked. That is, the terminal is configured to receive the same DCI at PDCCH candidate 1110, which is integration level 16 of Search space 1 1100, and at PDCCH candidate 1115, which is integration level 16 of Search space 2 1105. If a terminal receives (monitors) two linked PDCCH candidates and receives a DCI scheduling a PDSCH on the two PDCCH candidates, the terminal can assume that the time-frequency resources corresponding to both PDCCH candidates are unavailable for the PDSCH.

[0334] Some PDCCH candidates within a linked search space, or a portion of a search space, may not be used (monitored) for PDCCH reception for specific reasons. The terminal does not need to perform blind decoding for PDCCH candidates that cannot be used (monitored) for PDCCH reception. By not performing blind decoding in this way, the terminal's power consumption is reduced, and the unused blind decoding can be used to receive (monitor) other PDCCH candidates.

[0335] For example, PDCCH candidates that overlap with time-frequency resources in at least the following cases (e.g., case 1, case 2, or case 3) may be unavailable for PDCCH reception (monitoring):

[0336] In the first case, PDCCH candidates that overlap with the time-frequency resources used for SSB (SS / PBCH block) are unavailable for PDCCH reception. SSB is available as information regarding the terminal's initial cell connection and the terminal's QCL (quasi-co-located), and therefore the base station must periodically transmit SSB (SS / PBCH block) using the designated time-frequency resources. Consequently, downlink signals (including PDCCH) cannot be transmitted at locations that overlap with the time-frequency resource locations used for the SSB. For reference, the time-frequency location of the SSB may be set in the system information block received during the terminal's cell connection process, or during the RRC configuration process.

[0337] In the second case, PDCCH candidates that overlap with the rate matching resource set by the base station are unavailable for PDCCH reception. The rate matching resource may include at least one of RateMatchPattern, lte-CRS-ToMatchAround, LTE-CRS-PatternList-r16, or availableRB-SetsPerCell. Here, RateMatchPattern is a rate matching resource in the RB (resource block) unit set by the base station on the terminal, lte-CRS-ToMatchAround or LTE-CRS-PatternList-r16 is a rate matching resource in the RE (resource element) unit, and availableRB-SetsPerCell is a rate matching resource in the RB-set (set of RBs) unit. When lte-CRS-ToMatchAround or LTE-CRS-PatternList-r16 is set as a higher-layer signal, PDCCH candidates that overlap with time-frequency resources corresponding to lte-CRS-ToMatchAround or LTE-CRS-PatternList-r16 are always unavailable for PDCCH reception. RateMatchPattern is set as a higher-layer signal, and its availability may be further indicated by the DCI format used to schedule the PDSCH (e.g., DCI format 1_1, DCI format 1_2). If the availability of the RateMatchPattern is not indicated by the DCI format used to schedule the PDSCH, PDCCH candidates that overlap with time-frequency resources corresponding to the RateMatchPattern are unavailable for PDCCH reception. availableRB-SetsPerCell is set as a higher-layer signal and may indicate the available RB sets by DCI format 2_0, which indicates the slot format.

[0338] In a third case, PDCCH candidates that overlap with some symbols in the direction of the symbol are unavailable for PDCCH reception. For example, symbols that are set as uplink symbols, instructed as uplink symbols, or to which uplink signals or channels are scheduled are symbols used for uplink transmission, and therefore PDCCH candidates that overlap with such symbols are unavailable for PDCCH reception. Here, the set uplink symbol may be a symbol set as uplink by tdd-UL-DL-ConfigurationCommon in the system information block (SIB) received during the cell connection process, or by tdd-UL-DL-ConfigurationDedicated in the RRC signal. The instructed uplink symbol may be an uplink symbol instructed in DCI format 2_0 which instructs the slot format. The symbols to which uplink signals or channels are scheduled may be symbols to which PUSCH, SRS, PUCCH, etc. are scheduled in DCI format 0_0 / 0_1 / 0_2 / 1_0 / 1_1 / 1_2. Furthermore, the symbols on which the uplink signal or channel is scheduled may be symbols on which periodic transmission signals and channels configured as higher layers are scheduled, such as PUCCH, which transmits HARQ-ACKs for Configured grant PUSCH, periodic SRS, and SPS PDSCH.

[0339] In the first, second, or third cases described above, time-frequency resources that are unavailable for PDCCH reception (monitoring) can be referred to as reserved resources. However, such a term does not limit the technical scope of this disclosure.

[0340] If some of the linked search spaces or some of the PDCCH candidates within the search spaces are unavailable for PDCCH reception by the terminal for specific reasons, the PDCCH candidates linked to those PDCCH candidates may be used for PDCCH reception. For example, if search space 1 and search space 2 are linked, and some of the search spaces or some of the PDCCH candidates within search space 1 are unavailable for PDCCH reception due to the above-mentioned case (e.g., case 1, case 2, or case 3), i.e., overlap with a reserved resource, the terminal can receive PDCCH using the PDCCH candidates in linked search space 2. Here, the terminal can successfully receive DCI using one PDCCH candidate through the individual PDCCH decoding or joint PDCCH decoding described above.

[0341] It can be assumed that the received DCI schedules a PDSCH, and that the time-frequency resource range of the scheduled PDSCH overlaps with the linked PDCCH. In this case, the base station and terminal must determine which time-frequency resources of the PDSCH are unavailable for the PDSCH in order to successfully transmit and receive the PDSCH. Then, rate matching must be performed based on the resources available for the PDSCH. The following discloses a method by which a terminal determines the resources available for PDSCH reception.

[0342] [Method 1-1] PDSCH rate matching method that does not consider the possibility of reception (monitoring) in each search space

[0343] The terminal can determine the PDSCH rate matching method regardless of whether or not the PDCCH candidate can be received (monitored). Specifically, the terminal can receive a DCI format to schedule a PDSCH on the receiveable PDCCH candidate if at least one of the linked PDCCH candidates is a receiveable PDCCH candidate. The time-frequency resources corresponding to the receiveable PDCCH candidate and all PDCCH candidates linked to the receiveable PDCCH candidate can be determined to be resources unavailable for the PDSCH. In other words, even if a linked PDCCH candidate is a reserved resource (e.g., in the first, second, or third case) and is not used for PDCCH reception (monitoring), the terminal can determine that the time-frequency resources of the linked PDCCH candidate are resources unavailable for the PDSCH.

[0344] Figure 12 shows an example of a PDSCH rate matching method when a PDCCH candidate according to one embodiment of this disclosure overlaps with a reserved resource. More specifically, Figure 12 shows method 1-1 described above.

[0345] Referring to Figure 12, Search space 1 1200 and Search space 2 1205 are linked, and the terminal may be configured to have PDCCH candidate 1210, which is integration level 16 of Search space 1 1200, and PDCCH candidate 1215, which is integration level 16 of Search space 2 1205, linked. That is, the terminal may be configured to receive the same DCI at PDCCH candidate 1210, which is integration level 16 of Search space 1 1200, and PDCCH candidate 1215, which is integration level 16 of Search space 2 1205. In this case, some resources of the PDCCH candidate in Search space 1 1200 overlap with the time-frequency resources of reserved resources (e.g., in the first case, second case, or third case) 1250. Therefore, the terminal does not receive (monitor) the PDCCH at PDCCH candidate 1210 in Search space 1 1200, but it can receive (monitor) the PDCCH at PDCCH candidate 1215 in Search space 2 1205.

[0346] According to Method 1-1, when a terminal receives a DCI to schedule a PDSCH in Search space 2 1205 at candidate PDCCH 1215, the time-frequency resources corresponding to candidate PDCCH 1210 in Search space 1 1200 and candidate PDCCH 1215 in Search space 2 1205 may be included in the time-frequency resources unavailable for the PDSCH. That is, if the time-frequency resource on which the PDSCH is scheduled overlaps with the time-frequency resources of candidate PDCCH 1210 in Search space 1 1200 and candidate PDCCH 1215 in Search space 2 1205, the overlapping resource 1230 is unavailable for the PDSCH.

[0347] By making the determination as in Method 1-1, the terminal does not have to determine whether each PDCCH candidate is usable (monitored), which is superior from a practical standpoint. However, since the terminal knows that the linked PDCCH candidate will not be used, it will not use the time-frequency resources that overlap with the PDCCH candidate, even though they are available for use in the PDSCH, which may lead to resource loss. For example, in Figure 12, resource loss occurs because the terminal did not use PDCCH candidate 1210, which was not received (monitored) in Search space 1 1200, for the PDSCH.

[0348] [Method 1-2] PDSCH rate matching method based on the availability of reception (monitoring) for each search space

[0349] The terminal can determine the PDSCH rate matching method based on whether or not it can receive (monitor) the PDCCH candidates. Specifically, the terminal can receive the DCI format for scheduling the PDSCH using the receiveable PDCCH candidate if at least one of the linked PDCCH candidates is a receivable PDCCH candidate. The terminal can determine whether or not it can receive (monitor) the PDCCH candidate linked to the PDCCH candidate. If the linked PDCCH candidate is a receivable (monitorable) candidate, the terminal can determine that the time-frequency resources corresponding to the linked PDCCH candidate are unavailable for use in the PDSCH. If the linked PDCCH candidate is an unreceivable (monitorable) candidate, the terminal can determine that the time-frequency resources corresponding to the linked PDCCH are available for use in the PDSCH.

[0350] Figure 13 shows an example of a method for determining PDSCH rate matching based on whether or not each PDCCH candidate for each search space is received, according to one embodiment of the present disclosure. More specifically, Figure 13 shows method 1-2 described above.

[0351] Referring to Figure 13, the base station can be configured to link Search space 1 1300 and Search space 2 1305 to the terminal, and to link PDCCH candidate 1310, which is integration level 16 of Search space 1, and PDCCH candidate 1315, which is integration level 16 of Search space 2. In other words, the terminal may be configured to receive the same DCI from PDCCH candidate at integration level 16 of Search space 1 and PDCCH candidate at integration level 16 of Search space 2. Note that some resources of PDCCH candidate in Search space 1 overlap with the time-frequency resource of reserved resource (e.g., first case, second case, or third case) 1350. Therefore, the terminal will not receive (monitor) PDCCH candidate in Search space 1, but it can receive (monitor) PDCCH candidate in Search space 2.

[0352] According to Method 1-2, when a terminal receives a DCI scheduling a PDSCH in a PDCCH candidate in Search space 2, the time-frequency resource 1330 corresponding to the PDCCH candidate in Search space 2 may be included in the time-frequency resources unavailable for the PDSCH. However, since the terminal does not receive (monitor) a PDCCH in a PDCCH candidate in Search space 1, the time-frequency resources corresponding to the PDCCH candidate are available for the PDSCH.

[0353] By making the determination as in Method 1-2, resource loss can be reduced compared to Method 1-1. However, the terminal must determine whether or not to receive (monitor) the PDCCH each time for PDSCH rate matching, which can increase the complexity of the terminal.

[0354] [Method 1-2-1] Reserved resources include only signals and channels set as upper layers (DCI information is ignored).

[0355] In methods 1-2 described above, the reserved resources may include all of the first, second, and third cases. However, the reserved resources may include only some of the cases. As in method 1-2-1, the reserved resources may include only resources that are set as upper layers. More specifically, in the first case, since it is set as an upper layer signal (i.e., SIB and dedicated RRC signal), it may be included in the reserved resources of method 1-2. In the second case, lte-CRS-ToMatchAround or LTE-CRS-PatternList-r16 are set as upper layers and may be included in the reserved resources. In the second case, RateMatchPattern is set as an upper layer and may be additionally indicated by DCI. If RateMatchPattern is not additionally indicated by DCI, RateMatchPattern may be included in the reserved resources. If RateMatchPattern is additionally indicated by DCI, RateMatchPattern does not need to be included in the reserved resources. In the second case, since availableRB-SetsPerCell is specified in DCI format 2_0, it does not need to be included in the reserved resources. In the third case, the configured uplink symbol is configured as a higher layer and therefore may be included in the reserved resources. In addition, among the symbols on which uplink signals or channels are scheduled, periodic transmission signals and channels such as PUCCH, which transmits HARQ-ACK for Configured grant PUSCH, periodic SRS, and SPS PDSCH configured as higher layers, may be included in the reserved resources. However, the specified uplink symbol or uplink signals and channels scheduled in DCI format do not need to be included in the reserved resources.

[0356] As in Method 1-2-1, since the reserved resource includes only the time-frequency resources of the signal or channel set as the upper layer, the terminal may have two advantages. Firstly, since the reserved resource is determined only by the upper layer signal, the reserved resource does not change midway. Therefore, the terminal can determine the reserved resource with low complexity.

[0357] Secondly, when reserved resources include resources indicated by DCI, DCI reception may change the reserved resources, and when reserved resources change, the ability to receive (monitor) PDCCH candidates may change, which can affect PDSCH rate matching. Therefore, when reserved resources include resources indicated by DCI, misunderstandings may occur in PDSCH rate matching between base stations and terminals. However, since reserved resources only include signals or channels set as higher layers, such misunderstandings can be prevented.

[0358] [Method 1-2-2] Includes signals and channels set as upper layers in reserved resources, and signals and channels indicated in DCI.

[0359] In method 1-2-1 described above, reserved resources included only signals and channels set as higher layers, and did not include signals and channels indicated by DCI. However, some signals and channels indicated by DCI may be included in reserved resources. Here, we will describe the signals and channels indicated by DCI that may be included in reserved resources.

[0360] As a first example, all signals and channels indicated by DCI in the first, second, and third cases described above may be included in the reserved resources. That is, the reserved resources include all signals and channels corresponding to the first, second, and third cases.

[0361] As a second example, even if the RateMatchPattern in the second case is instructed by the DCI, the RateMatchPattern may be included in the reserved resources by the DCI. That is, if the DCI instructs the PDSCH that the RateMatchPattern is an unavailable resource, the RateMatchPattern may be included in the reserved resources. Even if the RateMatchPattern instructed by the DCI is included in the reserved resources in this way, since the DCI is the DCI that schedules the PDSCH, misunderstandings can be avoided in rate matching of the PDSCH between the base station and the terminal.

[0362] As a third example, the uplink symbols, uplink channels, and signals indicated in the DCI in the third case may be included in the reserved resources. The reason for selectively including only the uplink is that the base station uses the said area as an uplink and therefore cannot use it for downlink reception such as PDCCH reception and PDSCH reception. Therefore, even if the reserved resources include the uplink symbols, uplink channels, and signals indicated in the DCI, PDSCH reception is not possible with these symbols, so no misunderstanding occurs regarding the PDSCH rate between the terminal and the base station.

[0363] As a fourth example, in the second or third case, channels and signals indicated by DCI received in the common search space may be included in the reserved resources. However, channels and signals indicated by DCI received in the UE-specific search space do not need to be included in the reserved resources. This is because DCI received in the common search space may have higher reliability.

[0364] As a fifth example, in the second or third case, channels and signals indicated by DCI received in the UE-specific search space may be included in the reserved resources. However, channels and signals indicated by DCI received in the common search space do not need to be included in the reserved resources. This is because, in the case of the UE-specific search space, it is possible to set QCL settings and aggregation levels suitable for the terminal, which can result in higher reliability.

[0365] A base station can configure information about reserved resources on a terminal. This information may include information about the signals and channels included in the reserved resources. For example, in order to include only some of the channels and signals indicated by the DCI in the reserved resources, the base station can configure information about some of the channels and signals indicated by the DCI on the terminal.

[0366] [Method 1-3] PDSCH rate matching method when the wideband RS of the CORESET to which the linked PDCCH belongs overlaps with a reserved resource in any of the REs that receive it.

[0367] A terminal may set a wideband RS (reference signal) for a specific CORESET. In this case, the terminal can assume that all REs corresponding to the RS of the CORESET were transmitted by the same precoder. Therefore, the terminal can estimate the channels of the entire CORESET using the REs. If a wideband RS is not set, the terminal can assume that only the REs corresponding to the RS within the REG (resource element group) bundle of the CORESET are transmitted by the same precoder.

[0368] If a CORESET wideband RS is set on the terminal, and the RE corresponding to the RS overlaps with a reserved resource, the terminal must decide whether or not PDCCH reception (monitoring) is possible with the CORESET. In methods 1-1 to 1-2 described above, the time-frequency resource of the PDCCH candidate overlapped with a reserved resource, so the PDCCH candidate was clearly unusable for PDCCH reception (monitoring). However, here, the PDCCH candidate did not overlap with a reserved resource, but a part of the RE corresponding to the RS of the CORESET to which the PDCCH candidate belonged overlapped with a reserved resource. Therefore, the terminal can estimate the channel based on the non-overlapping RE and receive (monitor) the PDCCH candidate.

[0369] As a first example, when a CORESET wideband RS is set on a terminal, if the RE corresponding to the RS overlaps with a reserved resource, the terminal can determine that PDCCH reception (monitoring) is not possible with the CORESET. Furthermore, since reception is not possible, the PDCCH candidate resource can be used for PDSCH transmission.

[0370] As a second example, when a CORESET wideband RS is set on a terminal, if the RE corresponding to the RS overlaps with a reserved resource, the terminal can determine that PDCCH reception (monitoring) is possible with the CORESET. Furthermore, since reception is determined to be possible, the resource of the PDCCH candidate cannot be used for PDSCH transmission.

[0371] If, for example, a wideband RS is set in the first CORESET to which some of the linked search spaces configured on the terminal belong (associated), but a wideband RS is not set in the second CORESET to which the remaining search spaces belong (associated), the terminal must determine the resources available for PDSCH in the first or second CORESET. Based on the following examples 1 to 4, we propose a method for the terminal to determine the resources available for PDSCH in the first or second CORESET.

[0372] As a first example, if a terminal successfully receives a DCI that schedules a PDSCH for a PDCCH candidate in a PDCCH candidate in a search space associated with the first CORESET among the linked search spaces, it can determine that the resources corresponding to the PDCCH candidate in the first CORESET and the REs corresponding to the RS of the first CORESET are resources unavailable for PDSCH. The terminal can also determine that resources corresponding to the PDCCH candidate in the second CORESET linked to the aforementioned PDCCH candidate are also resources unavailable for PDSCH. However, the terminal can determine that the REs corresponding to the RS of the second CORESET are resources usable for PDSCH. This is because the second CORESET did not have a wideband RS set. The first example is equally applicable when a DCI that schedules a PDSCH is received for a PDCCH candidate in a PDCCH candidate in a search space associated with the second CORESET among the linked search spaces.

[0373] As a second example, if a terminal successfully receives a DCI that schedules a PDSCH for a PDCCH candidate in a PDCCH candidate in a search space associated with the first CORESET among the linked search spaces, the terminal can determine that the resources corresponding to the PDCCH candidate in the first CORESET and the REs corresponding to the RS in the first CORESET are resources that cannot be used for PDSCH. Furthermore, the terminal can determine that the resources corresponding to the PDCCH candidate in the second CORESET linked with the PDCCH candidate and the REs corresponding to the RS in the second CORESET are resources that cannot be used for PDSCH. In this second example, if a wideband RS is set in one CORESET, the terminal can determine resources that will not be used for PDSCH in a similar manner to if a wideband RS were set in a CORESET where a wideband RS is not set. This second example can also be applied in the same way when a DCI that schedules a PDSCH is received for a PDCCH candidate in a PDCCH candidate in a search space associated with the second CORESET among the linked search spaces.

[0374] As a third example, if a terminal successfully receives a DCI that schedules a PDSCH for a PDCCH candidate in a search space associated with the second CORESET among the linked search spaces, the terminal can determine that the resource corresponding to the PDCCH candidate in the second CORESET linked to the PDCCH candidate is a resource unavailable for PDSCH. Then, if all PDCCH candidates in the search space associated with the first CORESET overlap with reserved resources, the terminal can determine that the resource corresponding to the PDCCH candidate in the first CORESET and the RE corresponding to the RS in the first CORESET are resources available for PDSCH. That is, since all PDCCH candidates in the search space associated with the first CORESET overlap with reserved resources, all PDCCH candidates in the search space associated with the first CORESET are unreceivable. Since reception of the PDCCH candidates is impossible, the terminal can use the time-frequency resources of the PDCCH candidates for PDSCH.

[0375] As a fourth example, if a terminal successfully receives a DCI scheduling a PDSCH for a PDCCH candidate in a linked search space that is associated with the second CORESET, the terminal can determine that the resource corresponding to the PDCCH candidate in the second CORESET that is linked to the PDCCH candidate is a resource unavailable for PDSCH. Furthermore, if all PDCCH candidates in the search space that is associated with the first CORESET overlap with reserved resources, the terminal can determine that the resource corresponding to the PDCCH candidate in the first CORESET and the RE corresponding to the RS in the first CORESET are resources unavailable for PDSCH. In other words, since all PDCCH candidates in the search space that is associated with the first CORESET overlap with reserved resources, all PDCCH candidates in the search space that is associated with the first CORESET are unreceivable, but the terminal does not need to use the time-frequency resources of the PDCCH candidates for PDSCH.

[0376] The third and fourth examples described above are also applicable when wideband RS is set for the second coreset.

[0377] <Second Embodiment: Method for distinguishing between integrated level 8 and integrated level 16 and rate matching thereunder>

[0378] In the above, it was assumed that when a terminal receives a DCI that schedules a PDSCH, the time-frequency resources used to receive the PDCCH containing the DCI are not used for PDSCH reception. This is based on the assumption that the terminal knows the time-frequency resources used to receive the PDCCH. However, there may be cases where the terminal successfully receives a DCI under certain circumstances, but cannot determine the time-frequency resources used to receive the PDCCH containing the DCI. In the following explanation, this situation will be referred to as an ambiguous situation.

[0379] Figures 14A to 14D illustrate the ambiguous situation regarding AL determination in the examples.

[0380] Referring to Figures 14A to 14D, the base station can set a CORESET 1410 of 1 symbol length on the terminal, and the CORESET may be set using non-interleaved mapping. The base station can then set a search space 1410 belonging to the CORESET on the terminal. The search space may include at least one PDCCH candidate 1405 with an integration level of 8 and at least one PDCCH candidate 1400 with an integration level of 16. That is, the terminal must blind-decode at least one PDCCH candidate with an integration level of 8 and at least one PDCCH candidate with an integration level of 16 in the search space.

[0381] Referring to Figure 14A, a base station can transmit a DCI to schedule a PDSCH at PDCCH candidate 1400 with integration level 16. In this case, the PDCCH candidate includes a total of 16 CCEs, and the time-frequency resources corresponding to these 16 CCEs are not used for the PDSCH. That is, when the base station generates and transmits a PDSCH, it does not use the time-frequency resource area corresponding to the 16 CCEs for PDSCH transmission.

[0382] Referring to Figure 14B, the terminal can perform blind decoding of PDCCH candidate 1405, which is at integration level 8, and PDCCH candidate 1400, which is at integration level 16, in the search space. Here, if the starting CCE index of the PDCCH candidate at integration level 8 and the starting CCE index of the PDCCH candidate at integration level 16 are the same, the terminal can receive the DCI at the PDCCH at integration level 8. This is because, if the signal-to-noise ratio of the eight CCEs corresponding to the PDCCH candidate at integration level 8 is excellent, or if there is strong interference from the remaining eight CCEs, there is a probability that the base station transmitted the DCI at the PDCCH candidate at integration level 16, but it was decoded at the PDCCH candidate at integration level 8. In this case, since the terminal received a DCI that schedules a PDSCH at the PDCCH candidate at integration level 8, the terminal can assume that the eight CCEs corresponding to the PDCCH candidate at integration level 8 will not be used for PDSCH reception. Therefore, the terminal receives the PDSCH in the remaining resource area excluding the time-frequency resource area of ​​the eight CCEs. In this case, the terminal cannot successfully receive the PDSCH because the PDSCH transmitted by the base station and the PDSCH received by the terminal are transmitted / received in different resource areas.

[0383] Referring to Figure 14C, a base station can transmit a DCI scheduling a PDSCH at PDCCH candidate 1405 with integration level 8. In this case, the PDCCH candidate includes a total of 8 CCEs, and the time-frequency resources corresponding to these 8 CCEs are not used for the PDSCH. That is, when the base station generates and transmits the PDSCH, it does not use the time-frequency resource area corresponding to the 8 CCEs for PDSCH transmission.

[0384] Referring to Figure 14D, the terminal can perform blind decoding of PDCCH candidate 1405, which is at integration level 8, and PDCCH candidate 1400, which is at integration level 16, in the search space. Here, if the starting CCE index of the PDCCH candidate at integration level 8 and the starting CCE index of the PDCCH candidate at integration level 16 are the same, the terminal can receive the DCI at the PDCCH at integration level 16. This is because if the signal-to-noise ratio of the 8 CCEs corresponding to the PDCCH candidate at integration level 8 is excellent, and the signal-to-noise ratio of the remaining 8 CCEs is low, there is a probability that the base station transmitted the DCI at the PDCCH candidate at integration level 8, but it was decoded at the PDCCH candidate at integration level 16. In this case, since the terminal received the DCI that schedules the PDSCH at the PDCCH candidate at integration level 16, it can be assumed that the 16 CCEs corresponding to the PDCCH candidate at integration level 16 will not be used for the PDSCH reception. Therefore, the PDSCH is received in the remaining resource area excluding the time-frequency resource area of ​​the 16 CCEs. In this case, the PDSCH transmitted by the base station and the PDSCH received by the terminal are transmitted / received in different resource areas, so the terminal cannot successfully receive the PDSCH.

[0385] Figures 14A to 14D above are examples, and these examples can clearly be extended to other ambiguous situations.

[0386] Thus, the PDCCH candidate from which the base station transmits the DCI may differ from the PDCCH candidate from which the terminal receives the DCI. This can affect the terminal's PDCCH rate matching. Therefore, 3GPP Rel-15 defines the following terminal behavior.

[0387] 3GPP Rel-15 Terminal Operation: With one symbol, CORESET is set as the non-interleaving mapping, and the terminal is monitoring PDCCH candidates at integration level 8 and PDCCH candidates at integration level 16 that start from the same CCE index, if the terminal receives a DCI scheduling a PDSCH on the PDCCH candidate at integration level 8, the terminal will not use the time-frequency resources corresponding to the PDCCH candidate at integration level 16 for PDSCH reception.

[0388] As described above, 3GPP Rel-15 terminal operation assumes that the terminal receives the signal at the higher of the two aggregate levels, aggregate level 16, when there is ambiguity between aggregate level 8 and aggregate level 16. This assumption prevents PDSCH from using the time-frequency resources of the PDCCH candidate at aggregate level 16, resulting in resource loss, but it prevents misunderstandings regarding PDSCH rate matching between the base station and the terminal.

[0389] Figures 15A and 15B show an example of a PDSCH rate matching method in the case of ambiguity in the integration level determination according to one embodiment of the present disclosure.

[0390] Referring to Figures 15A and 15B, the terminal monitors PDCCH candidate 1505 at integration level (AL) 8 and PDCCH candidate 1510 at integration level 16, both starting from the same CCE 1520 in the search space 1500.

[0391] In Figure 15A, when a terminal receives a DCI scheduling a PDSCH on PDCCH candidate 1505 at integration level (AL) 8, the terminal does not use the time-frequency resource 1530 corresponding to a PDCCH at integration level 16 for PDSCH reception.

[0392] In Figure 15B, when a terminal receives a DCI that schedules a PDSCH at a PDCCH candidate 1510 of integration level (AL) 16, the terminal does not use the time-frequency resource 1535 corresponding to the PDCCH of integration level 16 for PDSCH reception.

[0393] Based on Figures 15A and 15B, the same resources are not used for PDSCH transmission regardless of which integration level (AL) PDCCH candidate the terminal receives a DCI scheduling PDSCH for, thus preventing misunderstandings regarding PDSCH rate matching between the base station and the terminal.

[0394] Figure 16 illustrates a situation in which some of the PDCCH candidates according to one embodiment of the present disclosure are not monitored.

[0395] Referring to Figure 16, the terminal is configured to monitor two PDCCH candidates 1605 and 1610, but one of them, PDCCH candidate 1610, overlaps with reserved resource 1650, and therefore this PDCCH candidate is not received (monitored). In the example in Figure 16, PDCCH candidate 1610, which corresponds to integration level (AL) 16, overlaps with reserved resource 1650, and therefore this PDCCH candidate cannot be received (monitored). In this situation, the terminal can receive a DCI scheduling a PDSCH for PDCCH candidate 1605 at integration level 8.

[0396] In the explanation of Figures 15A and 15B above, ambiguity can occur between integration level 8 and integration level 16, and therefore the terminal assumes integration level 16. However, in Figure 16, PDCCH candidates at integration level 16 are not received (monitored), so no further ambiguity occurs between integration level 8 and integration level 16. As a result, the terminal can receive PDSCH assuming integration level 8. In other words, when receiving PDSCH, the terminal does not need to use the time-frequency resource 1630 corresponding to integration level 8 for PDSCH reception.

[0397] Figures 17 to 20 show an example of a PDSCH rate matching method that takes into account the ambiguity of PDCCH repetitive transmission and aggregation level determination, and reserved resources, according to one embodiment of the present disclosure.

[0398] Referring to Figures 17 to 20, a terminal may be configured with two linked search spaces (e.g., search space 1 and search space 2), and each search space may be configured with at least one PDCCH candidate of integration level 8 and at least one PDCCH candidate of integration level 16. The PDCCH candidate of integration level 8 and the PDCCH candidate of integration level 16 may start from the same CCE in both search spaces. In this case, even if the terminal performs individual PDCCH decoding, the terminal may experience integration level ambiguity in both search spaces and search space 2. Moreover, even if the terminal performs joint PDCCH decoding, integration level ambiguity may occur in both search spaces. For reference, the two PDCCH candidates of integration level 8 in both linked search spaces always transmit the same DCI, and the two PDCCHs of integration level 16 always transmit the same DCI.

[0399] In one embodiment of this disclosure, the preferred operation of the terminal may be as follows:

[0400] If at least one of the two linked search spaces monitored by the terminal satisfies the <condition>, and the terminal receives a DCI scheduling a PDSCH on a PDCCH candidate of aggregation level 8 in one or two of the linked search spaces, the terminal does not use time-frequency resources corresponding to a PDCCH candidate of aggregation level 16 for PDSCH reception in both search spaces.

[0401] Here, the conditions are as follows:

[0402] <Conditions>: One symbol, a non-interleaving mapping CORESET is set, and it includes PDCCH candidates of integration level 8 and PDCCH candidates of integration level 16 that start from the same CCE index.

[0403] The aforementioned condition is one of the conditions under which the terminal cannot determine the received PDCCH candidate. The operation of the terminal under the aforementioned condition will now be described, but this operation may also be performed under other conditions under which the terminal cannot determine the received PDCCH candidate.

[0404] The terminal behavior proposed in 3GPP Rel-15 for resolving aggregate-level ambiguity for a single search space can be extended and applied to multiple linked search spaces.

[0405] Referring to Figures 17 to 20, we can consider the case where some PDCCH candidates are not received (monitored) in one of the linked search spaces. PDCCH candidates at integration level 16 in search space 1 are not received (monitored) because they overlap with reserved resources. However, PDCCH candidates at integration level 8 in search space 1, and PDCCH candidates at integration level 8 and integration level 16 in search space 2 may be received (monitored). In this case, the base station can transmit the DCI using one of two methods as follows.

[0406] As a first method, the base station can repeatedly transmit a DCI on linked PDCCH candidates of integrated level 8 in two linked search spaces. That is, the base station can repeatedly transmit the same DCI on PDCCH candidates of integrated level 8 in search space 1 and PDCCH candidates of integrated level 8 in search space 2.

[0407] As a second method, the base station can transmit DCI on the PDCCH candidate at integration level 16 in search space 2. That is, the base station transmits DCI on the PDCCH candidate at integration level 16 in search space 2, but does not need to transmit DCI on the PDCCH candidate at linked integration level 16 in search space 1 because the linked PDCCH candidate at integration level 16 in linked search space 1 overlaps with a reserved resource.

[0408] A terminal can receive a DCI that schedules a PDSCH by blind decoding the PDCCH using either individual PDCCH decoding or a joint PDCCH decoding scheme, as follows. When a terminal receives a DCI that schedules a PDSCH, the resources unavailable for the PDSCH may be determined based on the following method. For reference, the same PDSCH rate matching method can be used here regardless of the terminal's PDCCH decoding assumption (individual PDCCH decoding or joint PDCCH decoding). Therefore, the PDCCH decoding assumption of another terminal may be omitted in the following description.

[0409] [Method 2-1] PDSCH rate matching determination in each linked search space

[0410] An embodiment of [Method 2-1] will be described with reference to Figures 17 and 18. The terminal can determine resources unavailable to the PDSCH in each of the linked search spaces. More specifically, the terminal can determine the integration level in each of the linked search spaces based on the PDCCH received in each of the linked search spaces or the settings of each search space, and can determine resources unavailable to the PDSCH based on the respective search space integration levels.

[0411] Referring to Figure 17, we can assume that the terminal has received PDCCHs 1720 and 1710 of integration level 8 in the linked search spaces 1700 and 1705. The terminal can determine the integration level in each of the two linked search spaces. For example, in search space 2 1705, there are PDCCH candidate 1720 of integration level 8 and PDCCH candidate 1725 of integration level 16 that satisfy the above-mentioned <condition>, so the terminal can determine that the integration level in search space 2 is 16 (because integration level 16 is a superset of integration level 8). In other words, the terminal can assume that the time-frequency resources corresponding to the PDCCH candidates of integration level 16 in search space 2 are unavailable for use in PDCCH. In search space 1 1700, there are no PDCCH candidate 1710 of integration level 8 and PDCCH candidate 1715 of integration level 16 that satisfy the above-mentioned <condition>. This is because PDCCH candidates at integration level 16 in search space 1 are not received (monitored). Therefore, in search space 1, we can assume that the received integration level is integration level 8. In other words, the terminal can assume that the time-frequency resource 1730 corresponding to the PDCCH candidate at integration level 8 in search space 1 is unavailable for PDSCH.

[0412] The terminal behavior shown in Figure 17 above is also applicable when a terminal receives a PDCCH at integration level 16 in the linked search space. That is, even though the terminal receives a PDCCH at integration level 16 in the linked search space, as mentioned above, there is ambiguity between integration level 8 and integration level 16, so the same terminal behavior as when receiving a PDCCH at integration level 8 may be defined.

[0413] When a terminal receives a PDCCH at aggregation level 16 in the linked search space, a different operation than that shown in Figure 17 may be defined.

[0414] Referring to Figure 18, we can assume that the terminal has received PDCCHs 1815 and 1825 with integration level 16 in the linked search spaces 1800 and 1805. The terminal can determine the integration level in each of the two linked search spaces. For example, in search space 2 1805, there are PDCCH candidates 1820 with integration level 8 and 1825 with integration level 16 that satisfy the above-mentioned conditions, so the terminal can determine that the integration level in search space 2 is 16 (because integration level 16 is a superset of integration level 8, it is determined to be integration level 16). In other words, the terminal can assume that the time-frequency resource 1830 corresponding to the PDCCH candidate with integration level 16 in search space 2 is unavailable for use as a PDCCH. In search space 1, there are no PDCCH candidates with integration level 8 or integration level 16 that satisfy the above-mentioned conditions. This is because PDCCH candidate 1815 at integration level 16 in search space 1 is not received (monitored). Therefore, since there are no PDCCH candidates corresponding to the received integration level 16 in search space 1 1800, the terminal can assume that all time-frequency resources in search space 1 are available for PDCCH.

[0415] [Method 2-2] If there is ambiguity in any of the linked search spaces, PDSCH rate matching is determined based on the ambiguous search space.

[0416] An embodiment of [Method 2-2] will be described with reference to Figure 19. The terminal can determine resources unavailable to the PDSCH based on the settings of all linked search spaces to which the received PDCCH is transmitted. More specifically, if ambiguity in the integration level determination occurs in at least one of the linked search spaces to which the received PDCCH is transmitted, the terminal can determine the integration level in the search space where the ambiguity occurred to determine resources unavailable to the PDSCH, and then determine resources unavailable to the PDSCH in the remaining linked search spaces based on the integration level. For example, ambiguity in the integration level determination may occur in a search space that satisfies the above-mentioned <conditions>, i.e., a search space in which one symbol, a non-interleaving mapping CORESET is set, and which includes PDCCH candidates of integration level 8 and PDCCH candidates of integration level 16 starting from the same CCE index.

[0417] Figure 19 shows a PDSCH rate matching method according to one embodiment of the present disclosure, which takes into account PDCCH repetitive transmission, AL determination ambiguity, and reserved resources.

[0418] Referring to Figure 19, it can be assumed that the terminal has received PDCCHs in two linked search spaces 1900 and 1905. Here, the aggregation level of the received PDCCH may be either 8 or 16. The terminal can determine whether there is a search space among the two that satisfies the above-mentioned <condition>. For example, search space 11900 does not satisfy the <condition>, but search space 21905 does. By method 2-2, the terminal can determine the aggregation level in search space 2 where ambiguity regarding the aggregation level determination occurred. The aggregation level in search space 2 may be assumed to be 16 (because aggregation level 16 is a superset of aggregation level 8, it is determined to be aggregation level 16). That is, the terminal can assume that time-frequency resources corresponding to PDCCH candidates with aggregation level 16 in search space 2 are not used for PDSCH. The same aggregation level may be assumed in the remaining search space 1. Therefore, the terminal can assume that in search space 1, the time-frequency resource 1930 corresponding to the PDCCH candidate at integration level 16 is not used for the PDSCH.

[0419] [Method 2-3] If there is ambiguity in any of the linked search spaces, PDSCH rate matching is determined based on the unambiguous search space.

[0420] An embodiment of [Method 2-3] will be described with reference to Figure 20. The terminal can determine resources unavailable to the PDSCH based on the settings of all linked search spaces to which the received PDCCH is transmitted. More specifically, if ambiguity in the integration level determination occurs in at least one of the linked search spaces to which the received PDCCH is transmitted, the terminal can determine the integration level in the search space where no ambiguity occurs to determine resources unavailable to the PDSCH, and then determine resources unavailable to the PDSCH in the remaining linked search spaces based on the integration level. For example, ambiguity in the integration level determination may occur in a search space that satisfies the above-mentioned <conditions>, i.e., a search space in which one symbol, a non-interleaving mapping CORESET is set, and which includes PDCCH candidates of integration level 8 and PDCCH candidates of integration level 16 starting from the same CCE index.

[0421] Figure 20 shows a PDSCH rate matching method according to one embodiment of the present disclosure, taking into account PDCCH repetitive transmission, AL determination ambiguity, and reserved resources.

[0422] Referring to Figure 20, we can assume that the terminal receives PDCCH in two linked search spaces 2000 and 2005. Here, the integration level of the received PDCCH may be either 8 or 16. The terminal can determine whether one of the two search spaces satisfies the above-mentioned <condition>. For example, search space 1 2000 does not satisfy the <condition>, but search space 2 2005 does. By method 2-3, the terminal can determine the integration level in search space 1 where no ambiguity arises in determining the integration level.

[0423] If a terminal receives a PDCCH 2010 with integration level 8 in search space 1, the terminal can assume that integration level 8 is indeed the case. That is, in search space 1, the terminal can assume that the time-frequency resources of candidate PDCCH 2030 with integration level 8 are not used for the PDSCH. The terminal can then assume the same integration level in the remaining search space 2 2005. That is, in search space 2, the terminal can assume that the time-frequency resources of candidate PDCCH 2035 with integration level 8 are not used for the PDSCH.

[0424] If a terminal cannot receive a PDCCH with aggregation level 8 in search space 1, the terminal can assume that no PDCCH candidates with aggregation level 8 were transmitted in search space 1. That is, the terminal can use the time-frequency resources of search space 1 for the PDSCH. In this case, the terminal must determine the aggregation level in search space 2. At this time, since search space 2 satisfies the <condition>, it is preferable to determine it as aggregation level 16 (because aggregation level 16 is a superset of aggregation level 8). That is, the terminal can assume that the time-frequency resources of PDCCH candidates with aggregation level 16 in search space 2 are not used for the PDSCH.

[0425] Method 2-2 or Method 2-3 is a method in which the integration level is determined based on one of the linked search spaces, and the determined integration level is applied to the remaining search spaces. Here, one of the search spaces may be a search space that satisfies the <condition> in Method 2-2, or a search space that does not satisfy the <condition> in Method 2-3.

[0426] Alternatively, the aforementioned search space may be determined regardless of the <condition>. For example, among the linked search spaces, the search space with the lowest (or highest) search space index or ID (identity) may be selected. The terminal can determine the integration level based on the search space with the lowest (or highest) search space index or ID (identity) among the linked search spaces, and apply the determined integration level to the remaining search spaces.

[0427] As yet another example, the earliest (or latest) search space in time may be selected from among the linked search spaces. The terminal can determine the integration level based on the earliest (or latest) search space in time among the linked search spaces and apply the determined integration level to the remaining search spaces. Once one search space is determined, the assumed integration level for the search space may be determined by the method shown in Figures 17 to 20 above.

[0428] In Figures 17 to 20, both search spaces satisfied the condition when there were no reserved resources. Then, due to the reserved resources, one of the two search spaces satisfied the condition, while the other did not. Next, using Figures 21 to 23B, we will explain the case where, even without another reserved resource, one of the two search spaces satisfies the condition, and the other does not. For example, as mentioned above, whether or not the condition is satisfied may be determined by whether the search space has 1 symbol, a non-interleaving mapping CORESET set, and contains a PDCCH candidate of integration level 8 and a PDCCH candidate of integration level 16 that start from the same CCE index.

[0429] Figures 21 to 23 show rate matching of PDSCH in the case of ambiguity in PDCCH repetitive transmission and aggregation level determination according to one embodiment of the present disclosure.

[0430] Referring to Figures 21 to 23B, two search spaces, Search Space 1 and Search Space 2, are set up and linked to the terminal. For reference, the two search spaces may belong to different CORESETs, and different CORESETs may start with different CCE indices linked by the CORESET index (or ID (identity)). For example, PDCCH candidates at integration level 16 in Search Space 1 and Search Space 2 start with CCE index 0. However, PDCCH candidates at integration level 8 in Search Space 2 may start with CCE index 0, while PDCCH candidates at integration level 8 in Search Space 1 may start with CCE index 16. Therefore, the condition is met in the case of Search Space 2, but not in the case of Search Space 1. In such a search space setting, resources that are not used for PDSCH may be determined based on the method described below.

[0431] [Method 2-1] PDSCH rate matching determination in each linked search space

[0432] An embodiment of [Method 2-1] will be described with reference to Figure 21. The terminal can determine resources unavailable to the PDSCH in each of the linked search spaces. More specifically, the terminal can determine the integration level in each of the linked search spaces based on the PDCCH received in each of the linked search spaces or the settings of each search space, and can determine resources unavailable to the PDSCH based on the respective search space integration levels.

[0433] Figure 21 shows PDSCH rate matching in the case of repeated PDCCH transmission and AL determination ambiguity according to one embodiment of the present disclosure.

[0434] Referring to Figure 21, we can assume that the terminal has received PDCCHs 2110 and 2120, which are at integration level 8, in the linked search spaces 2100 and 2105. The terminal can determine the integration level in each of the two linked search spaces. For example, in search space 2 2105, there are PDCCH candidates 2120 at integration level 8 and PDCCH candidate 2125 at integration level 16 that satisfy the above-mentioned <condition>, so the terminal can determine that the integration level in search space 2 is 16 (because integration level 16 is a superset of integration level 8). In other words, the terminal can assume that the time-frequency resource 2135, which corresponds to the PDCCH candidate at integration level 16 in search space 2, is unavailable for use as a PDCCH. In search space 1 2100, there are no PDCCH candidates 2110 at integration level 8 or 2115 at integration level 16 that satisfy the above-mentioned <conditions>. This is because PDCCH candidates at integration level 16 in search space 1 are not received (monitored). Therefore, in search space 1, integration level 8, which is the received integration level, can be assumed. That is, the terminal can assume that the time-frequency resource 2130 corresponding to the PDCCH candidate at integration level 8 in search space 1 is unavailable for use in PDCCH.

[0435] [Method 2-2] If there is ambiguity in any of the linked search spaces, PDSCH rate matching is determined based on the ambiguous search space.

[0436] An embodiment of [Method 2-2] will be described with reference to Figure 22. The terminal can determine resources unavailable to the PDSCH based on the settings of all linked search spaces to which the received PDCCH is transmitted. More specifically, if ambiguity in the integration level determination occurs in at least one of the linked search spaces to which the received PDCCH is transmitted, the terminal can determine the integration level in the search space where the ambiguity occurred to determine resources unavailable to the PDSCH, and then, based on the integration level, determine resources unavailable to the PDSCH in the remaining linked search spaces.

[0437] Figure 22 shows PDSCH rate matching in the case of repeated PDCCH transmission and AL determination ambiguity according to one embodiment of the present disclosure.

[0438] Referring to Figure 22, assume that the terminal receives a PDCCH in two linked search spaces 2200 and 2205. Here, the aggregation level of the received PDCCH may be either 8 or 16. The terminal can determine whether one of the two search spaces satisfies the above-mentioned <condition>. For example, search space 1 2200 does not satisfy the <condition>, but search space 2 2205 does. By method 2-2, the terminal can determine the aggregation level in search space 2 where ambiguity in the aggregation level determination occurred. The aggregation level in search space 2 is assumed to be 16 (because aggregation level 16 is a superset of aggregation level 8, it is determined to be aggregation level 16). That is, the terminal can assume that the time-frequency resource 2235 corresponding to a PDCCH candidate with aggregation level 16 in search space 2 is not used for the PDSCH. For reference, the time-frequency resources of PDCCH candidate 2225 at integration level 16 in search space 2 2205 may include all of the time-frequency resources of PDCCH candidate 2220 at integration level 8. Therefore, for a terminal to assume that time-frequency resources corresponding to PDCCH candidates at integration level 16 in search space 2 are not used for PDSCH is equivalent to the terminal assuming that time-frequency resources corresponding to PDCCH candidates at integration level 8 and PDCCH candidates at integration level 16 in search space 2 are not used for PDSCH.

[0439] Furthermore, based on the aforementioned integration level, it is possible to determine which resources in the remaining search space 1 2200 are not used for PDSCH. In search space 2, we assumed that integration level 16 is the superset (or higher set) of integration level 8 and integration level 16. However, in search space 1, integration level 16 2215 is not the superset of integration level 8 2210. Therefore, preferably, the terminal can assume that in search space 1, the union 2230 of the time-frequency resources corresponding to PDCCH candidate 2210 of integration level 8 and the time-frequency resources corresponding to PDCCH candidate 2215 of integration level 16 is not used for PDSCH. That is, in search space 1, it may be assumed that neither of the two PDCCH candidates, not just one, is used for PDSCH.

[0440] [Method 2-3] If there is ambiguity in any of the linked search spaces, PDSCH rate matching is determined based on the unambiguous search space.

[0441] An embodiment of [Method 2-3] will be described with reference to Figures 23A and 23B. The terminal can determine resources unavailable to the PDSCH based on the settings of all linked search spaces to which the received PDCCH is transmitted. More specifically, if ambiguity in the integration level determination occurs in at least one of the linked search spaces to which the received PDCCH is transmitted, the terminal can determine the integration level in the search space where no ambiguity occurs to determine resources unavailable to the PDSCH, and then determine resources unavailable to the PDSCH in the remaining linked search spaces based on the integration level.

[0442] Figure 23A shows PDSCH rate matching in the case of repeated PDCCH transmission and AL determination ambiguity according to one embodiment of the present disclosure.

[0443] Referring to Figure 23A, the terminal can assume that it has received PDCCH 2310 and 2320 at integration level 8 in the two linked search spaces 2300 and 2305. The terminal can determine whether any of the two search spaces satisfies the above-mentioned <condition>. For example, search space 1 2300 does not satisfy the <condition>, but search space 2 2305 does. Method 2-3 allows the terminal to determine the integration level in search space 1, where no ambiguity arises in determining the integration level. If the terminal receives PDCCH 2310, which is at integration level 8, in search space 1, the terminal can assume that integration level 8 is the case. That is, in search space 1, the terminal can assume that the time-frequency resource 2330, a candidate PDCCH at integration level 8, is not used for the PDCCH. The terminal can then assume the same integration level in the remaining search space 2. In other words, the terminal can assume that the time-frequency resource 2335 of the PDCCH candidate at integration level 8 in the search space 2 is not used for the PDSCH.

[0444] Figure 23B shows PDSCH rate matching in the case of repeated PDCCH transmission and AL determination ambiguity according to one embodiment of the present disclosure.

[0445] Referring to Figure 23B, the terminal can assume that it has received PDCCH 2315 and 2325 at integration level 16 in the two linked search spaces 2300 and 2305. The terminal can determine whether any of the two search spaces satisfies the above-mentioned <condition>. For example, search space 1 2300 does not satisfy the <condition>, but search space 2 2305 does. Method 2-3 allows the terminal to determine the integration level in search space 1 where no ambiguity arises in determining the integration level. If the terminal receives PDCCH 2315 at integration level 16 in search space 1, the terminal can assume that integration level 16 is the case. That is, in search space 1, the terminal can assume that the time-frequency resource 2340, a candidate PDCCH at integration level 16, is not used for the PDSCH. The terminal can then assume the same integration level in the remaining search space 2. In other words, the terminal can assume that the time-frequency resource 2345 of the PDCCH candidate at integration level 16 in the search space 2 will not be used for the PDSCH.

[0446] Figures 24 to 26 are flowcharts illustrating a PDSCH rate matching method according to one embodiment of the present disclosure. More specifically, Figures 24, 25, and 26 show flowcharts for Method 2-1, Method 2-2, and Method 2-3, respectively.

[0447] Referring to Figure 24, at step 2400, the terminal may have multiple search spaces configured from the base station. Each of the multiple search spaces may include at least one PDCCH candidate with integration level 8 and at least one PDCCH candidate with integration level 16.

[0448] At step 2405, the terminal may be configured to have linked search spaces from the base station, among the multiple search spaces, where the same DCI is repeatedly transmitted (i.e., PDCCH repeated transmission).

[0449] At step 2410, the terminal can receive a DCI scheduling a PDSCH in the linked search space.

[0450] At step 2415, the terminal can determine the integration level of the PDCCH candidate to which the DCI is transmitted, based on the setting information of each of the linked search spaces. When determining the integration level in each search space, if the <condition> is met, it can be determined to be integration level 16, and if the <condition> is not met, it can be determined to be integration level 8. Furthermore, when determining the integration level in one search space, it is not necessary to consider the other linked search spaces.

[0451] At 2420 levels, the terminal can rate-match and receive PDSCH based on the aggregation level determined in each search space.

[0452] Referring to Figure 25, at step 2500, the terminal may have multiple search spaces configured from the base station. Each of the multiple search spaces may include at least one PDCCH candidate with integration level 8 and at least one PDCCH candidate with integration level 16.

[0453] At step 2505, the terminal may be configured to have a linked search space from which the same DCI is repeatedly transmitted from the base station among the multiple search spaces.

[0454] At step 2510, the terminal can receive a DCI scheduling a PDSCH in the linked search space.

[0455] At step 2515, the terminal can determine (decide) a search space that satisfies the <condition> based on the setting information of the linked search space.

[0456] At 2520 steps, the terminal can determine the integration level in a search space that satisfies the aforementioned <conditions>. For example, if the <conditions> are met, the terminal can determine that the integration level is 16.

[0457] At step 2525, the terminal can determine the integration level in a search space that does not satisfy the <condition> based on the determined integration level. Since the terminal determined that the integration level of the search space that satisfies the <condition> is 16, it can determine that the integration level of the search space that does not satisfy the <condition> is 16. If, for example, the integration level 16 in the search space that does not satisfy the <condition> is not a hyperset of integration level 8 (i.e., the time-frequency resources of the PDCCH with integration level 16 do not completely contain the time-frequency resources of the PDCCH with integration level 8), the terminal can determine that the integration levels of the search space that does not satisfy the <condition> are 8 and 16.

[0458] At step 2530, the terminal can rate-match and receive PDSCH based on the aggregation level determined in the search space that satisfies the <condition> and the aggregation level determined in the search space that does not satisfy the <condition>. The time-frequency resources of PDCCH candidates with aggregation level 16 in the search space that satisfies the <condition> are not used for PDSCH, and the time-frequency resources of PDCCH candidates with aggregation level 8 and PDCCH candidates with aggregation level 16 in the search space that does not satisfy the <condition> are not used for PDSCH.

[0459] Referring to Figure 26, at step 2600, the terminal may have multiple search spaces configured from the base station. Each of the multiple search spaces may include at least one PDCCH candidate of integration level 8 and at least one PDCCH candidate of integration level 16.

[0460] At step 2605, the terminal may be configured to have a linked search space from which the same DCI is repeatedly transmitted, among the multiple search spaces, from the base station.

[0461] At step 2610, the terminal can receive a DCI scheduling a PDSCH in the linked search space.

[0462] At step 2615, the terminal can determine (decide) which search spaces do not satisfy the <condition> based on the setting information of the linked search spaces.

[0463] At step 2620, the terminal can determine the integration level in a search space that does not satisfy the aforementioned <condition>. Since there is no other integration level ambiguity when the <condition> is not satisfied, the terminal can determine that the integration level assumed when receiving the DCI is the integration level of the search space that does not satisfy the <condition>.

[0464] In 2625 steps, the terminal can determine (decide) the integration level in a search space that satisfies the <condition> based on the determined integration level. The terminal can also determine that the integration level is the same as the integration level in a search space that does not satisfy the <condition>.

[0465] At step 2630, the terminal can rate-match and receive PDSCH based on the aggregation level determined in the search space that does not satisfy the <condition> and the aggregation level determined in the search space that satisfies the <condition>. Assuming the same aggregation level determined in the search space that does not satisfy the <condition> and the search space that satisfies the <condition>, resources not used for PDSCH can be determined.

[0466] [Method 2-4: Including an integrated level indicator]

[0467] Methods 2-1, 2-2, and 2-3 propose a method in which a terminal determines the integration level, while Method 2-4 proposes a method in which a base station transmits information regarding the PDCCH integration level to the DCI.

[0468] A base station can transmit a DCI that schedules a PDSCH, including an indicator that indicates the aggregation level of the PDCCH to which the DCI is transmitting. For example, the indicator may consist of one bit, which can indicate either aggregation level 8 or aggregation level 16. A terminal can receive a DCI that schedules a PDSCH, identify the indicator from the received DCI, and determine the aggregation level using the indicator. The terminal can apply the determined aggregation level to all linked search spaces. That is, time-frequency resources of PDCCH candidates corresponding to the same aggregation level indicated by the indicator in all linked search spaces do not need to be used for PDSCH reception.

[0469] As yet another example, the indicator may be indicated by a specific combination of DCI fields included in the DCI rather than by separate bits. For example, if the MCS (modulation and coding scheme) field included in the DCI received by the terminal indicates a low MCS value, the channel conditions may be poor and can therefore be considered as integration level 16. For example, if the TDRA (time-domain resource assignment) field included in the DCI received by the terminal indicates repeated transmission of PDSCH, the channel conditions may be poor and can therefore be considered as integration level 16.

[0470] As yet another example, the indicator may be indicated by borrowing some of the existing bits of the DCI rather than a separate bit. For example, a specific bit of the FDRA (frequency-domain resource assignment) field included in the DCI received by the terminal may be reused for the indicator purpose. For example, a specific bit of the MCS field included in the DCI received by the terminal may be reused for the indicator purpose. Of the MCS field, the specific bit may be the MSB (most significant bit). When using the MSB bit of the MCS field, the MCS field can indicate 4 bits, and a maximum of 16 code points can be indicated. Here, the maximum of 16 code points may consist of code points corresponding to low MCS and code points that indicate only the modulation order.

[0471] As yet another example, the indicator may be indicated by a separate RNTI. That is, when receiving DCI scrambled with a specific RNTI, the aggregation level of the PDCCH transmitted by the DCI can be considered a specific value (e.g., 8 or 16). Exemplaryly, when receiving DCI scrambled with an MCS-C-RNTI, the terminal can consider the aggregation level of the PDCCH transmitted by the DCI to be 16. This is because the MCS-C-RNTI is used when higher reliability is required.

[0472] For reference, when a terminal receives a DCI for a PDCCH candidate where the integration level is 1, 2, or 4, the terminal may ignore the indicator. In other words, the indicator is available when the terminal receives a DCI for a PDCCH candidate where the integration level is 8 or 16. Furthermore, the indicator is available when the linked search space satisfies the <condition> and the terminal receives a PDCCH candidate at integration level 8 or 16. Otherwise, the terminal may ignore the indicator.

[0473] Alternatively, the terminal can assume one aggregation level without the aforementioned indicator. This means assuming that the base station always transmits PDCCHs at a predetermined aggregation level whenever the <condition> is met. For example, one aggregation level value among 8 or 16 can be assumed. The base station can set one value for the terminal at the higher layer. The terminal can expect to receive only PDCCH candidates corresponding to one aggregation level value, provided there is a linked search space that satisfies the <condition>. For example, if the base station instructs the terminal to set 16 as one value, the terminal will receive (monitor) PDCCH candidates at aggregation level 16, but does not need to receive (monitor) PDCCH candidates at aggregation level 8. Thus, there is no need for further ambiguity regarding the aggregation level.

[0474] <Third Embodiment: Method for distinguishing between integration level 8 and integration level 16, and method for determining PUCCH resources based on the same>

[0475] A terminal may have up to 32 PUCCH resources configured for a PUCCH set. A DCI that schedules a PDSCH or instructs a HARQ-ACK transmission (e.g., an SPS PDSCH release DCI, a DCI that triggers a type-3 HARQ-ACK codebook, a DCI that instructs Scell ​​dormancy, etc.) must indicate one of the up to 32 PUCCH resources. However, currently, such DCIs include a maximum of 3 bits of a PUCCH resource indicator field. Therefore, in addition to the 3-bit PUCCH resource indicator field, other information must also be used to indicate one of the up to 32 PUCCH resources. To this end, 3GPP Rel-15 uses the lowest CCE index of the PDCCH from which the DCI is sent (or the starting CCE index / first CCE index).

[0476] Figure 27 shows a method for determining PUCCH resources according to one embodiment of the present disclosure.

[0477] Referring to Figure 27, the lowest CCE index for the PDCCH X 2700 at integration level 8 is n CCE =16(2755), and the lowest CCE index for PDCCH Y 2705 at integration level 16 is n CCE =0(2750). If a terminal receives a DCI on PDCCH X at integration level 8, the PUCCH resource may be determined by the lowest CCE index, which is 16. In the example in Figure 27, PUCCH resource A (2710) is indicated. If a terminal receives a DCI on PDCCH Y at integration level 16, the PUCCH resource may be determined by the lowest CCE index, which is 0. In the example in Figure 27, PUCCH resource B 2715 is indicated. Thus, since the lowest CCE index of the PDCCH from which the terminal receives the DCI is different, different PUCCH resources may be indicated.

[0478] More specifically, the PUCCH resource may be determined by equation 3.

[0479] [Formula 3]

[0480]

number

[0481] In formula 3, N CCE,p This is the number of CCEs included in CORESET p from which DCI was received, and N CCE,p This is the lowest CCE index (or starting CCE index) of the PDCCH from which DCI was received. Δ PRI This is the value of the PUCCH resource indicator field in DCI, which is one of the values ​​0, 1, 2, 3, 4, 5, 6, or 7. PUCCH r is the number of PUCCH resources set within the PUCCH resource set, greater than or equal to 8 and less than or equal to 32. According to formula 3, r PUCCH is 0, 1, ..., RPUCCH It can have one of the values ​​-1.

[0482] To determine the PUCCH resource using the aforementioned formula 3, the terminal must determine the lowest CCE index (or starting CCE index) of the PDCCH from which the DCI was received. As shown in Figures 15A and 15B and the <Conditions> above, the terminal may have received a DCI, but it may be ambiguous whether the DCI was transmitted on a PDCCH at aggregation level 8 or on a PDCCH at aggregation level 16. However, referring to Figures 15A and 15B and the <Conditions>, a PDCCH at aggregation level 8 and a PDCCH at aggregation level 16 can always start from the same CCE. Therefore, although there is ambiguity in the aggregation level, the terminal can determine the lowest CCE index (or starting CCE index) without ambiguity. In other words, when a terminal receives (monitors) a PDCCH in a search space that includes PDCCH candidates of integration level 8 and PDCCH candidates of integration level 16, with one symbol and a non-interleaving mapping CORESET set, the terminal can unambiguously determine the lowest CCE index (or starting CCE index).

[0483] Linked search spaces may have different lowest CCE indices (or starting CCE indices) for each PDCCH received within each search space. Therefore, in this case, the lowest CCE indices for PDCCH received within one search space must be used. For example, among the linked search spaces, the lowest CCE indices for PDCCH received within the search space with the lowest search space index can be used.

[0484] However, referring to Figure 28, if one search space in a linked search space satisfies the <condition> but the other search space does not, it can be ambiguous as to which CCE index the terminal must use to determine the PUCCH resource.

[0485] As mentioned above, the conditions are as follows:

[0486] <Conditions>: 1 symbol, non-interleaving mapping CORESET is set, and includes PDCCH candidates of integration level 8 and PDCCH candidates of integration level 16 that start from the same CCE index.

[0487] Figure 28 shows an example of a method for determining PUCCH resources in the case of PDCCH repetitive transmission and ambiguity in the aggregation level determination according to one embodiment of the present disclosure.

[0488] Referring to Figure 28, in search space 2 2805 that satisfies the <condition>, the terminal cannot determine whether the aggregation level of the PDCCH from which the DCI was transmitted is 8 or 16. In search space 1 2800 that does not satisfy the <condition>, the terminal can determine which PDCCH was transmitted. However, as mentioned above, the terminal can perform individual PDCCH decoding using only search space 2, and the channel environment corresponding to search space 1 may deteriorate (for example, high interference or blocking of the TRP (transmission and reception point) from which search space 1 is transmitted), allowing the terminal to receive the PDCCH in search space 1. In this case, the terminal can receive the PDCCH using only the PDCCH transmitted in search space 2. Therefore, a problem arises when the terminal tries to determine the lowest CCE index (start CCE index) of the PDCCH it received in search space 1. For reference, as mentioned above, the PUCCH resource can be determined using the search space with the lowest index among the linked search spaces, i.e., the lowest CCE index (starting CCE index) of the PDCCH received in search space 1.

[0489] [Method 3-1] Use the lowest CCE index (starting CCE index) of the PDCCH received in the search space that satisfies the <condition>.

[0490] Referring to Figure 28, in a linked search space that satisfies the <condition> (e.g., search space 2 2805), the lowest CCE index (start CCE index) can be determined without ambiguity, even if there is ambiguity regarding the aggregation level. Therefore, the terminal and base station can determine the PUCCH resource using the lowest CCE index (start CCE index) 2860. In other words, if a terminal receives a PDCCH transmitting a DCI, and the aggregation level of the PDCCH is 8 (2820) or 16 (2825), and the PDCCH satisfies the <condition> in at least one of the linked search spaces, the PUCCH resource can be determined using the lowest CCE index (start CCE index) 2860 of the PDCCH in the search space that satisfies the <condition>. In general cases other than the above, the PUCCH resource can always be determined using the lowest CCE index (start CCE index) of the PDCCH received in a search space with a low index.

[0491] [Method 3-2] Use the lowest CCE index (starting CCE index) of a single integration level, PDCCH.

[0492] Referring to Figure 28, the search space with the lowest search space index is search space 1 2800, and it can be ambiguous whether a PDCCH at integration level 8 or integration level 16 was received in this search space. To resolve this ambiguity, we can assume that it was received at one integration level. For example, we can assume that a PDCCH was always received at a low integration level, i.e., integration level 8 2810. Referring to Figure 28, the terminal has the lowest CCE index (start CCE index) at integration level 8 in search space 1 with the lowest index, n CCEThe PUCCH resource can be determined based on =16(2855). As another example, we can assume that the PDCCH is always received at the highest aggregation level, i.e., aggregation level 16(2815). Referring to Figure 28, the terminal has the lowest CCE index (start CCE index) of aggregation level 16, which is the highest aggregation level in the search space 1 with the lowest index n CCE The PUCCH resource can be determined based on =0 (2850).

[0493] [Method 3-3] Use the lowest CCE index (starting CCE index) of the received PDCCH.

[0494] The terminal can use the lowest CCE index (start CCE index) of the received PDCCH. In this case, the terminal ignores the potential ambiguity regarding the aggregation level of the PDCCH and assumes the received PDCCH is the PDCCH transmitted by the base station.

[0495] Referring to Figure 28, assuming the terminal receives a PDCCH2810 at integration level 8, the lowest CCE index (start CCE index) of the PDCCH at integration level 8 in search space 1 is n, which is the search space with the lowest index. CCE The PUCCH resource can be determined based on =16(2855).

[0496] Because the terminal ignored the ambiguity regarding the PDCCH aggregation level, it may potentially transmit a PUCCH with the wrong PUCCH resource. However, at least the base station can see which PUCCH the terminal might be using.

[0497] For example, referring to Figure 28, the terminal is the lowest CCE index (start CCE index) of the PDCCH at aggregation level 8 of search space 1, which is the search space with the lowest index, n CCEn is the lowest CCE index (starting CCE index) of the PUCCH resource and the PDCCH at integration level 16, determined based on =16. CCE Based on the value = 0, one PUCCH resource is selected from the PUCCH resources determined. Therefore, the base station can determine which PUCCH was used for transmission by receiving and decoding both of those PUCCH resources.

[0498] The method of indicating the integration level of the PDCCH using the DCI described in Method 2-4 above may be applied when determining the PUCCH. The terminal receives the DCI and can obtain an indicator that indicates the integration level from the DCI, and can determine the integration level using the indicator. Based on the integration level, the PDCCH may be selected in the search space with the lowest index, and the PUCCH resource may be determined by the lowest CCE index (start CCE index) of the PDCCH.

[0499] Figure 29 is a flowchart of terminal operation according to one embodiment of the present disclosure. The order of operations in Figure 29 may be changed, two or more operations may be performed in combination, or some steps may be omitted.

[0500] Referring to Figure 29, at step S2910, the terminal can confirm the first and second search space sets. The base station can confirm the first and second search space sets to be set on the terminal and set the first and second search space sets on the terminal.

[0501] As described above, the search space is a set of downlink control channel candidates consisting of CCEs that a terminal should attempt to decode at a given integration level, and there can be various integration levels in which one set consists of 1, 2, 4, 8, or 16 CCEs. The search space set can be defined as the set of search spaces at all configured integration levels.

[0502] Each search space set may be associated with a CORESET. For example, the first search space set may be associated with the first CORESET, and the second search space set may be associated with the second CORESET. A search space index may be assigned to each search space set. The search space index is information for identifying the search space set; for example, the first search space set may be assigned a first index, and the second search space set may be assigned a second index.

[0503] The first and second search space sets may be linked to each other based on configuration information. PDCCH may be repeatedly received based on the linked search space sets. For example, the configuration information may be received from a base station. The configuration information may include information (or identifiers) for linking the first and second search space sets to each other for repeated reception of PDCCH. For example, the configuration information may include the first and / or second information described above.

[0504] For example, the first search space set may include a first PDCCH candidate with CCE integration level 8 and a third PDCCH candidate with CCE integration level 16. The index of the first CCE of the first PDCCH candidate (the index of the starting CCE) may be the same as the index of the first CCE of the third PDCCH candidate (the index of the starting CCE). The second search space set may include a second PDCCH candidate with CCE integration level 8 and a fourth PDCCH candidate with CCE integration level 16. The index of the first CCE of the second PDCCH candidate (the index of the starting CCE) may be different from the index of the first CCE of the fourth PDCCH candidate (the index of the starting CCE). For example, the terminal can verify that the CCEs-to-REGs mapping type of the first CORESET associated with the first search space set is set to non-interleaving mapping, and that the time duration of the first CORESET is one symbol.

[0505] At stage S2920, the terminal can receive a PDCCH. The base station can transmit a PDCCH to the terminal. The PDCCH may receive a DCI that schedules a PDSCH or a DCI that instructs the transmission of a HARQ-ACK (e.g., an SPS PDSCH release DCI, a DCI that triggers a type-3 HARQ-ACK codebook, a DCI that instructs Scell ​​dormancy, etc.). For example, the PDCCH may be received based on a first search space set and a second search space set, respectively. As an example, the PDCCH may be received based on the first PDCCH candidate and the second PDCCH candidate. Or, the PDCCH may be received based on the third PDCCH candidate and the fourth PDCCH candidate.

[0506] At step S2930, the terminal can determine the PUCCH resource. The PUCCH resource may be determined based on the index of the first CCE (or starting CCE) among the CCEs for PDCCH.

[0507] For example, if the second index of the second search space set is smaller than the first index of the first search space set, the first CCE may be determined based on the second search space set. Specifically, the index of the first CCE (or starting CCE) may be determined based on the CCE integration level of the PDCCH candidate associated with the second search space set having a smaller index. As an example, the index of the first CCE of the second PDCCH candidate with CCE integration level 8 in the second search space (the starting CCE index) may be different from the index of the first CCE of the fourth PDCCH candidate with CCE integration level 16 (the starting CCE index). In this case, the index of the first CCE (or starting CCE) may be determined based on the index of the first CCE of the fourth PDCCH candidate with CCE integration level 16 (the starting CCE index).

[0508] The PUCCH resource may be determined by further considering the value of the PUCCH Resource Indicator field in the DCI transmitted via PDCCH.

[0509] At step S2940, the terminal can transmit a PUCCH based on the determined PUCCH resource. The base station can receive the PUCCH from the terminal. For example, the PUCCH may contain HARQ-ACK information.

[0510] The proposed methods and / or embodiments described above (for example, the first embodiment, the second embodiment, the third embodiment, etc.) may be carried out in combination with each other.

[0511] Furthermore, the proposed method and / or embodiments described above (for example, the first embodiment, the second embodiment, the third embodiment, etc.) may be carried out using the terminal and / or base station shown in Figures 30 and 31.

[0512] Figure 30 shows the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0513] Referring to Figure 30, the terminal may include a transceiver comprising a terminal receiver 3000 and a terminal transmitter 3010, a memory (not shown), and a terminal processing unit (or terminal control unit or processor) 3005. The transceiver 3000, 3010, memory, and terminal processing unit 3005 of the terminal may operate according to the terminal communication method described above. However, the components of the terminal are not limited to the example described above. For example, the terminal may include more or fewer components than those described above. The transceiver, memory, and processor may also be implemented in the form of a single chip.

[0514] The transmitting and receiving unit can transmit and receive signals with the base station. Here, the signals may include control information and data. For this purpose, the transmitting and receiving unit may consist of an RF transmitter that upconverts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplified the received signal and downconverts its frequency. However, this is merely one embodiment of the transmitting and receiving unit, and the components of the transmitting and receiving unit are not limited to an RF transmitter and an RF receiver.

[0515] Furthermore, the transmitting and receiving unit can receive signals via a wireless channel and output them to the processor, and transmit signals output from the processor via the wireless channel.

[0516] Memory can store programs and data necessary for the operation of the terminal. It can also store control information or data contained in signals transmitted and received by the terminal. Memory may consist of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. There may also be multiple memory units.

[0517] Furthermore, the terminal processing unit 3005 can control a series of processes to enable the terminal to operate according to the embodiment described above. For example, the processor can control the terminal components to receive DCI, which is composed of two layers, and to receive a large number of PDSCHs simultaneously. For example, the terminal processing unit 3005 checks a first search space set associated with a first CORESET and a second search space set associated with a second CORESET that are linked based on the configuration information. The first search space set having a first index includes a first PDCCH candidate having CCE AL 8 and a third PDCCH candidate having CCE AL 16, and the second search space set having a second index includes a second PDCCH candidate having CCE AL 8 and a fourth PDCCH candidate having CCE AL 16. The terminal processing unit receives PDCCHs via the transmitting / receiving unit based on the first and second PDCCH candidates or the third and fourth PDCCH candidates, and determines a PUCCH resource based on the index of the first CCE. However, if the first index of the first search space set is greater than the second index of the second search space set, the index of the first CCE is determined based on the CCE AL of the PDCCH candidate associated with the second search space set having the second index, and the unit is configured to transmit a PUCCH via the transmitting / receiving unit using the determined PUCCH resource. There may be multiple terminal processing units 3005, and each terminal processing unit 3005 can perform terminal component control operations by executing a program stored in memory.

[0518] Figure 31 shows a base station in a wireless communication system according to one embodiment of the present disclosure.

[0519] Referring to Figure 31, the base station may include a transceiver unit comprising a base station receiver 3100 and a base station transmitter 3110, a memory (not shown), and a base station processing unit (3105, or a base station control unit or processor). The base station's transceiver units 3100, 3110, memory, and base station processing unit 3105 can operate according to the base station communication method described above. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than those described above. The transceiver unit, memory, and processor may also be implemented in the form of a single chip.

[0520] The transmitting / receiving unit can send and receive signals to and from the terminal. Here, the signal may include control information and data. For this purpose, the transmitting / receiving unit may consist of an RF transmitter that upconverts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplified the received signal and downconverts its frequency. However, this is merely one embodiment of the transmitting / receiving unit, and the components of the transmitting / receiving unit are not limited to an RF transmitter and an RF receiver.

[0521] Furthermore, the transmitting and receiving unit can receive signals via the wireless channel and output them to the base station processing unit 3105, and can transmit signals output from the processor via the wireless channel.

[0522] The memory can store programs and data necessary for the operation of the base station. It can also store control information or data contained in the signals transmitted and received by the base station. The memory may consist of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. There may also be multiple memory units.

[0523] The base station processing unit 3105 can control a series of processes so that the base station can operate according to the embodiments of the present disclosure described above. For example, the base station processing unit 3105 can configure a two-layer DCI containing assignment information for multiple PDSCHs and control each component of the base station to transmit it. For example, the base station processing unit 3105 checks a first search space set associated with a first CORESET and a second search space set associated with a second CORESET that are linked based on configuration information, but the first search space set having a first index includes a first PDCCH candidate having CCE AL 8 and a third PDCCH candidate having CCE AL 16, and the second search space set having a second index includes a second PDCCH candidate having CCE AL 8 and a fourth PDCCH candidate having CCE AL 16, and is configured to send a PDCCH to a terminal based on the first and second PDCCH candidates or based on the third and fourth PDCCH candidates, and to receive a PUCCH from the terminal using a PUCCH resource, the PUCCH resource is checked based on the index of the first CCE of the PDCCH, and if the first index of the first search space set is greater than the second index of the second search space set, the index of the first CCE is the CCE of the PDCCH candidate associated with the second search space set having a second index Related to AL.

[0524] There may be multiple base station processing units 3105, and each base station processing unit 3105 can perform control operations for the base station components by executing a program stored in memory.

[0525] The methods described in the claims or specifications of this disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0526] When implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. The one or more programs stored on the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to perform the method according to the embodiments described in the claims or specification of this disclosure.

[0527] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), electrically erasable programmable read-only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs), or other forms of optical storage devices, or magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these combinations. Furthermore, each constituent memory may include multiple instances.

[0528] Furthermore, the program may be stored in an attachable storage device accessible via a communication network such as the Internet, intranet, LAN (Local Area Network), WLAN (Wide LAN), or SAN (Storage Area Network), or a combination thereof. Such a storage device can be connected to the device performing the embodiment of the disclosure via an external port. Alternatively, a separate storage device on the communication network may be connected to the device performing the embodiment of the disclosure.

[0529] In the specific embodiments of the present disclosure described above, the components included in the invention are expressed singly or plurally in the specific embodiments presented. However, the singular or plural expression is selected for the convenience of explanation, according to the presented situation, and the present disclosure is not limited to singly or plural components. Therefore, a component expressed as plural may consist of a singular component, and a component expressed as singular may consist of a plural component. On the other hand, the embodiments of the present disclosure disclosed in this specification and drawings are merely examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it is obvious to a person with ordinary skill in the art to which the present disclosure belongs that other modifications based on the technical idea of ​​the present disclosure are possible. Furthermore, each of the above embodiments may be used in combination as necessary. For example, a base station and a terminal may be operated by combining a part of one embodiment of the present disclosure with a part of another embodiment. For example, a base station and a terminal may be operated by combining a part of the first embodiment and a part of the second embodiment of the present disclosure with a part of a second embodiment. Furthermore, although the above embodiment was presented based on an FDD LTE system, other modifications based on the technical concept of the above embodiment can be implemented for other systems such as TDD LTE systems, 5G, or NR systems.

[0530] On the other hand, in the drawings illustrating the method of the present invention, the order of explanation does not necessarily correspond to the order of execution, and the order of execution may be changed or the methods may be executed in parallel.

[0531] Alternatively, drawings illustrating the method of the present invention may omit some components and include only some components, without departing from the essence of the present invention.

[0532] Furthermore, the methods of the present invention may be implemented by combining some or all of the contents included in each embodiment, without departing from the essence of the invention.

[0533] While this disclosure has been illustrated and described with reference to various embodiments, a person with ordinary skill in the art to which this disclosure belongs will understand that it can be readily modified in other specific forms without departing from the spirit and scope of this disclosure as defined by the attached patent claims and their equivalents. [Explanation of symbols]

[0534] 3000 Terminal Receiver 3005 Terminal Processing Unit 3010 Terminal Transmitter 3100 Base station receiving unit 3105 Base station processing unit 3110 Base station transmitter

Claims

1. A method performed by a terminal in a wireless communication system, The step of receiving setting information for a first search space (SS) set and a second SS set, wherein the first SS set having a first index includes a first PDCCH (physical downlink control channel) candidate having a CCE (control channel element) integration level (AL) 8 and a third PDCCH candidate having a CCE AL 16, and the second SS set having a second index includes a second PDCCH candidate having a CCE AL 8 and a fourth PDCCH candidate having a CCE AL 16, and The step of receiving PDCCH based on the aforementioned setting information, A step in determining a PUCCH (physical uplink control channel) resource based on the index of a first CCE to the PDCCH, wherein if the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE is determined based on a PDCCH candidate having a CCE AL16 associated with the second SS set having the second index. The step of transmitting a PUCCH based on the PUCCH resource determined above. Methods that include...

2. The mapping type of the CCE to REG (resource element group) of the first control resource set (CORESET) associated with the first SS set is set to non-interleaved mapping, and the time length of the first CORESET is 1 symbol. The method according to claim 1, characterized in that the index of the first CCE of the first PDCCH candidate is the same as the index of the first CCE of the third PDCCH candidate.

3. If, in the second SS set, the index of the first CCE of the second PDCCH candidate is different from the index of the first CCE of the fourth PDCCH candidate, the index of the first CCE for the PDCCH is determined from the index of the first CCE of the fourth PDCCH candidate having the CCE AL 16. The method according to claim 2, characterized in that the PDCCH is received based on the first PDCCH candidate and the second PDCCH candidate or based on the third PDCCH candidate and the fourth PDCCH candidate.

4. The second SS set is associated with the second CORESET, The method according to claim 1, characterized in that the PUCCH resource is further determined based on the value of the PUCCH resource indicator field in the downlink control information (DCI) of the PDCCH.

5. The aforementioned configuration information includes information regarding the linking of the first SS set and the second SS set for PDCCH iterations. The method according to claim 1, characterized in that the first SS set and the second SS set are linked based on the setting information.

6. A method performed by a base station in a wireless communication system, Steps include: transmitting configuration information for a first search space (SS) set and a second SS set to a terminal, wherein the first SS set having a first index includes a first PDCCH (physical downlink control channel) candidate having a CCE (control channel element) integration level (AL) 8 and a third PDCCH candidate having a CCE AL 16, and the second SS set having a second index includes a second PDCCH candidate having a CCE AL 8 and a fourth PDCCH candidate having a CCE AL 16; A step of transmitting PDCCH to the terminal based on the aforementioned configuration information, The steps include receiving PUCCH (physical uplink control channel) from the terminal based on the PUCCH (physical uplink control channel) resource and Includes, The PUCCH resource is identified based on the index of the first CCE to the PDCCH, A method wherein, when the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE of the PDCCH is associated with a PDCCH candidate having a CCE AL16 associated with the second SS set having the second index.

7. The mapping type of the CCE to REG (resource element group) of the first control resource set (CORESET) associated with the first SS set is set to non-interleaved mapping, and the time length of the first CORESET is 1 symbol. The index of the first CCE of the first PDCCH candidate is the same as the index of the first CCE of the third PDCCH candidate. The method according to claim 6, characterized in that, in the second SS set, if the index of the first CCE of the second PDCCH candidate is different from the index of the first CCE of the fourth PDCCH candidate, the index of the first CCE for the PDCCH is determined from the index of the first CCE of the fourth PDCCH candidate having the CCE AL 16.

8. The PUCCH resource is further confirmed based on the value of the PUCCH resource indicator field in the downlink control information (DCI) of the PDCCH. The second SS set is associated with the second CORESET, The method according to claim 6, characterized in that the PDCCH is transmitted based on the first PDCCH candidate and the second PDCCH candidate or based on the third PDCCH candidate and the fourth PDCCH candidate.

9. The aforementioned configuration information includes information regarding the linking of the first SS set and the second SS set for PDCCH iterations. The method according to claim 6, characterized in that the first SS set and the second SS set are linked based on the setting information.

10. A terminal in a wireless communication system, Transmitter / receiver unit, Setting information for the first search space (SS) set and the second SS set is received via the transmitting and receiving unit, the first SS set having a first index includes a first PDCCH (physical downlink control channel) candidate having a CCE (control channel element) integration level (AL) 8 and a third PDCCH candidate having a CCE AL 16, the second SS set having a second index includes a second PDCCH candidate having a CCE AL 8 and a fourth PDCCH candidate having a CCE AL 16, The PDCCH is received via the transmitting / receiving unit based on the setting information. Based on the index of the first CCE to the PDCCH, the PUCCH (physical uplink control channel) resource is determined, and if the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE is determined based on the PDCCH candidate having the CCE AL16 associated with the second SS set having the second index. A control unit is configured to transmit a PUCCH based on the determined PUCCH resource via the transmitting / receiving unit, and is functionally connected to the transmitting / receiving unit. A terminal that includes this.

11. The mapping type of the CCE to REG (resource element group) of the first control resource set (CORESET) associated with the first SS set is set to non-interleaved mapping, and the time length of the first CORESET is 1 symbol. The index of the first CCE of the first PDCCH candidate is the same as the index of the first CCE of the third PDCCH candidate. The second SS set is associated with the second CORESET, The terminal according to claim 10, characterized in that, in the second SS set, if the index of the first CCE of the second PDCCH candidate is different from the index of the first CCE of the fourth PDCCH candidate, the index of the first CCE for the PDCCH is determined from the index of the first CCE of the fourth PDCCH candidate having the CCE AL 16.

12. The aforementioned configuration information includes information regarding the linking of the first SS set and the second SS set for PDCCH iterations. The PUCCH resource is further determined based on the value of the PUCCH resource indicator field in the downlink control information (DCI) of the PDCCH. The terminal according to claim 10, characterized in that the PDCCH is received based on the first PDCCH candidate and the second PDCCH candidate or based on the third PDCCH candidate and the fourth PDCCH candidate.

13. A base station in a wireless communication system, Transmitter / receiver unit, The terminal receives configuration information for a first search space (SS) set and a second SS set, the first SS set having a first index includes a first PDCCH (physical downlink control channel) candidate having a CCE (control channel element) integration level (AL) 8 and a third PDCCH candidate having a CCE AL 16, the second SS set having a second index includes a second PDCCH candidate having a CCE AL 8 and a fourth PDCCH candidate having a CCE AL 16, Based on the aforementioned configuration information, PDCCH is transmitted to the terminal. A control unit is configured to receive PUCCH (physical uplink control channel) from the terminal based on the PUCCH (physical uplink control channel) resource, and is functionally connected to the transmitting / receiving unit. Includes, The PUCCH resource is identified based on the index of the first CCE to the PDCCH, When the first index of the first SS set is greater than the second index of the second SS set, the index of the first CCE of the PDCCH is associated with a PDCCH candidate having a CCE AL16 associated with the second SS set having the second index, the base station.

14. The mapping type of the CCE to REG (resource element group) of the first control resource set (CORESET) associated with the first SS set is set to non-interleaved mapping, and the time length of the first CORESET is 1 symbol. The index of the first CCE of the first PDCCH candidate is the same as the index of the first CCE of the third PDCCH candidate. The second SS set is associated with the second CORESET, The base station according to claim 13, characterized in that, in the second SS set, if the index of the first CCE of the second PDCCH candidate is different from the index of the first CCE of the fourth PDCCH candidate, the index of the first CCE for the PDCCH is determined from the index of the first CCE of the fourth PDCCH candidate having the CCE AL 16.

15. The aforementioned configuration information includes information regarding the linking of the first SS set and the second SS set for PDCCH iterations. The base station according to claim 13, characterized in that the PDCCH is transmitted based on the first PDCCH candidate and the second PDCCH candidate or based on the third PDCCH candidate and the fourth PDCCH candidate.

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