Terminal and base station in a wireless communication system and methods performed thereby

Abstract

A terminal and a base station in a wireless communication system and methods performed thereby are disclosed. The terminal includes a transceiver and a controller. The controller is configured to receive, from the base station, information indicating resources to be rate matched. The information is provided through a radio resource control (RRC) message and includes information for time resources and information for frequency resources, monitor, in a search space associated with a control resource set (CORESET), physical downlink control channel (PDCCH) candidates without monitoring PDCCH candidates overlapping with the resources. The resources are defined by a combination of the time resources and the frequency resources, and identify downlink control information (DCI) based on a result of monitoring the PDCCH candidates. The search space is defined by a set of PDCCH candidates for an aggregation level, each PDCCH candidate is defined by a set of control channel elements (CCEs) corresponding to the aggregation level, each CCE consists of six resource element groups (REGs), and each REG is one resource block (RB) across one orthogonal frequency division multiplexing (OFDM) symbol.

Description

[0001] This application is a divisional application of the invention patent application filed on September 6, 2018 (international filing date), with application number 201880058423.5 and invention title "Terminal and Base Station in Wireless Communication System and Method Thereof". Technical Field

[0002] This disclosure generally relates to a method and apparatus for transmitting and receiving downlink control and data channels in a wireless communication system, and more specifically, to a method for a base station to configure or instruct a terminal to use a time-slot-based or non-time-slot-based scheduling scheme, and to a method for a terminal to transmit and receive data according to a configuration or instruction transmitted by a base station. Background Technology

[0003] To meet the growing demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. 5G or pre-5G communication systems are also referred to as "beyond 4G networks" or "late LTE systems." The implementation of 5G communication systems in higher frequency (millimeter wave, mmWave) bands (e.g., the 60 GHz band) is being considered to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are being discussed in 5G communication systems. Furthermore, in 5G communication systems, development is underway to improve system networks based on: advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation. In 5G systems, the following technologies have been developed: Hybrid Frequency Shift Keying (FSK) and Orthogonal Amplitude Modulation (FQAM) and Sliding Window Overlay Coding (SWSC) as Advanced Coding and Modulation (ACM); and Filter Bank Multicarrier (FBMC), Non-Orthogonal Multiple Access (NOMA) and Sparse Code Multiple Access (SCMA) as Advanced Access Technologies.

[0004] The internet is now evolving into the Internet of Things (IoT), in which distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE), a combination of IoT technologies and big data processing technologies connected to cloud servers, has emerged. Because IoT implementation requires technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have recently been studied. Such an IoT environment can provide intelligent internet technology services, creating new value for life by collecting and analyzing data generated between connected things. Through the convergence and combination of existing information technology (IT) with various industrial applications, IoT can be applied to a wide range of fields, including: smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0005] Consistent with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, MTC, and M2M communication can be implemented through beamforming, MIMO, and array antennas. The application of cloud RAN, as a big data processing technology as described above, can also be considered an example of the convergence between 5G and IoT technologies.

[0006] Next-generation wireless communication systems require improvements in the transmission and reception of data and control channels. Summary of the Invention

[0007] Technical issues

[0008] Next-generation wireless communication systems require improvements in the transmission and reception of data and control channels.

[0009] Solution

[0010] 5G systems can be designed to support both slot-based and non-slot-based scheduling techniques. One aspect of this disclosure provides: a method for a base station to configure or instruct a terminal on a slot-based or non-slot-based scheduling scheme, and a method for a terminal to transmit and receive data according to the configuration or instructions transmitted by the base station.

[0011] 5G systems can be designed for base stations to transmit time slot format indicators to terminals via group-common downlink control information (DCI). The time slot format can be configured as a combination of downlink symbols, uplink symbols, and unknown symbols. One aspect of this disclosure provides a method for utilizing unknown symbols.

[0012] 5G systems can be designed to reserve specific time / frequency resources for various purposes. Neither the base station nor the terminal uses the reserved resources for transmission or reception. One aspect of this disclosure provides a method for a base station to transmit DCI and a method for a terminal to monitor the CORESET of DCI, wherein a portion of the control resource set (CORESET) used for transmitting downlink control channels is configured as reserved resources.

[0013] According to one aspect of this disclosure, a method for a terminal in a wireless communication system is provided. The method includes: receiving first information of a configuration control resource set (CORESET) from a base station; receiving second information of a resource configured for rate matching through the base station from the base station; determining at least one physical downlink control channel (PDCCH) candidate in a CORESET that overlaps with the resource; and receiving downlink control information from the base station by excluding the at least one PDCCH candidate from a search space to be monitored in the CORESET.

[0014] According to another aspect of this disclosure, a terminal in a wireless communication system is provided. The terminal includes: a transceiver configured to transmit and receive signals; and a controller configured to receive first information of a configuration control resource set (CORESET) from a base station, receive second information of resources configured for rate matching through the base station from the base station, determine at least one physical downlink control channel (PDCCH) candidate in a CORESET overlapping with the resources, and receive downlink control information from the base station by excluding the at least one PDCCH candidate from a search space to be monitored in the CORESET.

[0015] According to another aspect of this disclosure, a method for using a base station in a wireless communication system is provided. The method includes: transmitting first information of a configuration control resource set (CORESET) to a terminal; transmitting second information of configuring resources for rate matching through the base station to the terminal; and transmitting downlink control information on PDCCH candidates in the CORESET by having the terminal exclude at least one physical downlink control channel (PDCCH) candidate that overlaps with the resource from a search space to be monitored in the CORESET.

[0016] According to another aspect of this disclosure, a base station in a wireless communication system is provided. The base station includes: a transceiver configured to transmit and receive signals; and a controller configured to transmit first information of a configuration control resource set (CORESET) to a terminal; second information of configuring resources for rate matching through the base station to the terminal; and to transmit downlink control information on PDCCH candidates in the CORESET by having the terminal exclude at least one physical downlink control channel (PDCCH) candidate that overlaps with the resource from a search space to be monitored in the CORESET.

[0017] According to another aspect of this disclosure, a terminal in a wireless communication system is provided, the terminal comprising: a transceiver configured to transmit or receive signals; and a controller configured to: receive information from a base station indicating resources for rate matching, wherein the information is provided via a Radio Resource Control (RRC) message and includes information for time resources and information for frequency resources; monitor Physical Downlink Control Channel (PDCCH) candidates in a search space associated with a control resource set CORESET, without monitoring PDCCH candidates that overlap with resources, wherein the resources are defined by a combination of time resources and frequency resources, and PDCCH candidates that overlap with resources are not monitored; and identify Downlink Control Information (DCI) based on the results of monitoring PDCCH candidates, wherein the search space is defined by a set of PDCCH candidates for aggregation levels, each PDCCH candidate being defined by a set of Control Channel Elements (CCEs) corresponding to the aggregation level, each CCE consisting of six Resource Element Groups (REGs), and each REG being a Resource Block (RB) spanning one Orthogonal Frequency Division Multiplexing (OFDM) symbol.

[0018] According to another aspect of this disclosure, a method performed by a terminal in a wireless communication system is provided, the method comprising: receiving from a base station information indicating resources for rate matching, wherein the information is provided via a Radio Resource Control (RRC) message and includes information for time resources and information for frequency resources; monitoring Physical Downlink Control Channel (PDCCH) candidates in a search space associated with a Control Resource Set (CORESET), without monitoring PDCCH candidates that overlap with resources, wherein the resources are defined by a combination of time resources and frequency resources, and PDCCH candidates that overlap with resources are not monitored; and identifying Downlink Control Information (DCI) based on the result of monitoring the PDCCH candidates, wherein the search space is defined by a set of PDCCH candidates for an aggregation level, each PDCCH candidate being defined by a set of Control Channel Elements (CCEs) corresponding to the aggregation level, each CCE consisting of six Resource Element Groups (REGs), and each REG being a Resource Block (RB) spanning one Orthogonal Frequency Division Multiplexing (OFDM) symbol.

[0019] According to another aspect of this disclosure, a base station in a wireless communication system is provided, the base station comprising: a transceiver configured to transmit or receive signals; and a controller configured to: transmit information to a terminal indicating resources for rate matching, wherein the information is provided via a Radio Resource Control (RRC) message and includes information for time resources and information for frequency resources, and transmit downlink signals to the terminal on physical downlink control channel (PDCCH) candidates in a search space associated with a control resource set (CORESET) by excluding PDCCH candidates that overlap with the resources, wherein the resources are defined by a combination of time resources and frequency resources, wherein PDCCH candidates that overlap with the resources are not monitored, and wherein the search space is defined by a set of PDCCH candidates for aggregation levels, each PDCCH candidate being defined by a set of control channel elements (CCEs) corresponding to the aggregation level, each CCE consisting of six resource element groups (REGs), and each REG being a resource block (RB) spanning one orthogonal frequency division multiplexing (OFDM) symbol.

[0020] According to another aspect of this disclosure, a method performed by a base station in a wireless communication system is provided, the method comprising: sending information to a terminal indicating resources for rate matching, wherein the information is provided via a Radio Resource Control (RRC) message and includes information for time resources and information for frequency resources; and sending downlink signals to the terminal on Physical Downlink Control Channel (PDCCH) candidates in a search space associated with a Control Resource Set (CORESET) by excluding PDCCH candidates that overlap with the resources, wherein the resources are defined by a combination of time resources and frequency resources, wherein PDCCH candidates that overlap with the resources are not monitored, and wherein the search space is defined by a set of PDCCH candidates for aggregation levels, each PDCCH candidate being defined by a set of Control Channel Elements (CCEs) corresponding to the aggregation level, each CCE consisting of six Resource Element Groups (REGs), and each REG being a Resource Block (RB) spanning one Orthogonal Frequency Division Multiplexing (OFDM) symbol.

[0021] Advantages of the present invention

[0022] According to various embodiments of the present invention, communication efficiency in next-generation wireless communication systems can be improved. Attached Figure Description

[0023] The above and other aspects, features, and advantages of certain embodiments of this disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0024] Figure 1This is a diagram illustrating the basic time-frequency resource structure used for transmitting downlink data and control channels in an LTE system;

[0025] Figure 2 This is a diagram showing the Physical Downlink Control Channel (PDCCH) and the Enhanced PDCCH (EPDCCH) as downlink physical channels carrying LTE DCI;

[0026] Figure 3 This is a diagram illustrating the basic units of time and frequency resources used for downlink control channels in a 5G system;

[0027] Figure 4 This is a diagram illustrating how to configure the CORESET for transmitting downlink control channels in a 5G wireless communication system;

[0028] Figure 5 This is a diagram illustrating the 5G timeslot format;

[0029] Figure 6 This is a diagram of a method used to transmit DMRS in a 5G communication system;

[0030] Figure 7 This is a diagram illustrating the configuration of the bandwidth portion (BWP) in a 5G communication system;

[0031] Figure 8 This is a diagram of a dynamic time-division duplex (TDD) method based on a time slot format indicator according to an embodiment;

[0032] Figure 9 This is a diagram of the method for utilizing unknown symbols according to an embodiment;

[0033] Figure 10 This is a diagram of a downlink control information transmission method according to an embodiment;

[0034] Figure 11 This is a block diagram of a terminal according to an embodiment;

[0035] Figure 12 This is a block diagram of a base station according to an embodiment. Detailed Implementation

[0036] Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. The same reference numerals are used throughout the drawings to refer to the same or similar parts. To avoid obscuring the subject matter of this disclosure, detailed descriptions of well-known functions and structures incorporated herein are omitted.

[0037] To avoid obscuring the subject matter of this disclosure, detailed descriptions of technical specifications well-known in the art and not directly related to this disclosure have been omitted. Unnecessary descriptions have been omitted to make the subject matter of this disclosure clear.

[0038] For the reasons stated above, some elements in the accompanying drawings are enlarged, omitted, or simplified, and in practice, elements may have different dimensions and / or shapes than those shown in the drawings. Throughout the drawings, identical or equivalent parts are indicated by the same reference numerals.

[0039] The advantages and features of this disclosure, as well as methods of implementing this disclosure, can be more readily understood through the following detailed description and accompanying drawings of the embodiments. However, this disclosure may be embodied in many different forms and is not intended to be limited to the embodiments set forth herein. Rather, embodiments are provided to make this disclosure thorough and complete and to fully convey the contents of this disclosure to those skilled in the art, and this disclosure is defined by the appended claims and their equivalents. Throughout this disclosure, the same reference numerals refer to the same elements.

[0040] It will be understood that each block of a flowchart and / or block diagram, and combinations of blocks in a flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or another programmable data processing device, such that instructions executed via the processor of the computer or other programmable data processing device create means for implementing the functions / actions specified in the flowchart and / or block diagram. These computer program instructions can also be stored in a non-transitory computer-readable storage medium that can instruct the computer or other programmable data processing device to function in a particular manner, such that instructions stored in the non-transitory computer-readable storage medium produce manufacturing embedded instruction means for implementing the functions / actions specified in the flowchart and / or block diagram. Computer program instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device, thereby producing a computer-implemented process, such that instructions executing on the computer or other programmable device provide steps for implementing the functions / actions specified in the flowchart and / or block diagram.

[0041] Furthermore, each block diagram may illustrate a module, segment, or portion of code, which includes at least one or more executable instructions for performing a certain logical function(s). It should also be noted that, in several modifications, the functions of the blocks may be executed in different orders. For example, depending on their function, two consecutive blocks may be executed substantially simultaneously or in reverse order.

[0042] According to embodiments, the term "module" refers to, but is not limited to, software or hardware components that perform certain tasks, such as field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs). Modules can advantageously be configured to reside on addressable storage media and execute on one or more processors. Therefore, modules can include, for example, components (such as software components, object-oriented software components, class components, and task components), processes, functions, attributes, procedures, subroutines, fragments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided in components and modules can be combined into fewer components and modules, or further separated into additional components and modules. Additionally, components and modules can be implemented such that they execute one or more central processing units (CPUs) in a device or secure multimedia card.

[0043] Mobile communication systems have evolved to include: high-speed, high-quality packet data communication systems as defined in the 3rd Generation Partnership Project (3GPP) (such as High-Speed ​​Packet Access (HSPA), LTE (or Evolved Universal Terrestrial Radio Access (E-UTRA)) and Advanced LTE (LTE-A)), High-Rate Packet Data (HRPD) as defined in 3GPP2 (3GPP2), and the Institute of Electrical and Electronics Engineers (IEEE) standard 802.16e, which can provide data and multimedia services beyond the earlier voice-oriented services.

[0044] LTE, as a representative broadband wireless communication system, uses Orthogonal Frequency Division Multiplexing (OFDM) in the downlink and Single-Carrier Frequency Division Multiple Access (SC-FDMA) in the uplink. The term "uplink" refers to the radio transmission path from a terminal, interchangeably called a User Equipment (UE) or Mobile Station (MS), to a base station (BS), interchangeably called an Evolved Node B (eNB), while the term "downlink" refers to the radio transmission path from the base station to the terminal. This multiple access scheme is characterized by allocating time-frequency resources for transmitting user-specific data and control information without overlap (i.e., maintaining orthogonality), in order to distinguish between user-specific data and control information.

[0045] As the next-generation communication system after LTE, 5G communication systems should be designed to meet the diverse service requirements of users and service providers. The services supported by 5G systems can be categorized into three types: enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable and low-latency communications (URLLC).

[0046] Compared to the data rates supported by legacy LTE, LTE-A, and LTE-A Pro, eMBB aims to provide exceptionally high data rates. For example, eMBB aims to increase the peak data rate per base station to 20Gbps in the downlink (DL) and 10Gbps in the uplink (UL). Simultaneously, eMBB aims to improve the perceived data rate for users. To meet these demands, it is necessary to improve signal transmission / reception technologies, including MIMO technology. The data rate requirements of 5G communication systems can be met by using frequency bandwidths wider than 20MHz in the 3 to 6 GHz or higher frequency bands (replacing the current 2 GHz LTE band).

[0047] Furthermore, mMTC is considered to support IoT application services. To effectively provide mMTC-based IoT application services, it is necessary to ensure ample access resources for terminals within a cell, improve terminal coverage and battery life, and reduce equipment manufacturing costs. Considering the nature of IoT terminals attached to various sensors and devices to provide communication capabilities, IoT services should be designed to support a large number of terminals within a cell (e.g., 1,000,000 terminals / square kilometer). Due to the nature of IoT services, mMTC terminals may be located in coverage holes such as building basements, requiring wider coverage compared to other services supported in 5G communication systems. Characterized by their low cost and difficulty in battery replacement, mMTC terminals should be designed with long battery life.

[0048] Finally, URLLC targets cellular-based mission-critical communication services requiring ultra-low latency and ultra-high reliability, such as remote robotics and machine control, industrial automation, drones, telemedicine, and emergency alert services. Therefore, URLLC services demand ultra-low latency and ultra-high reliability. For example, URLLC services must meet requirements of air interface latency of less than 0.5 milliseconds and a packet error rate of less than or equal to 10⁻⁵. In this regard, to support URLLC services, 5G systems must support shorter Transmission Time Intervals (TTIs) than other services and allocate extensive resources in the frequency band. Therefore, 5G systems must support short TTIs (shorter than TTIs for other services) for URLLC and allocate extensive resources in the frequency band to ensure the reliability of communication links.

[0049] The three categories of services (eMBB, URLLC, and mMTC) can be reused in a single system. To meet the specific needs of different services, different transmission / reception schemes and parameters can be used to transmit / receive different types of services.

[0050] The following description of the frame structure for LTE and LTE-A systems is provided with reference to the accompanying drawings.

[0051] Figure 1 This is a diagram illustrating the basic time-frequency resource structure used for transmitting downlink data and control channels in an LTE system.

[0052] refer to Figure 1 The horizontal axis represents time, and the vertical axis represents frequency. The smallest transmission unit in the time domain is an OFDM symbol, and Nsymb OFDM symbols 101 form a time slot 102, while two time slots form a subframe 105. Each time slot spans 0.5 ms, and each subframe spans 1.0 ms. A radio frame 104 is a time unit consisting of 10 subframes. In the frequency domain, the smallest transmission unit is a subcarrier, and the total system transmission bandwidth consists of NBW subcarriers 109. In the time-frequency resource structure, the basic resource unit is a resource element (RE) 106 indicated by the OFDM symbol index and subcarrier index. A resource block (RB) (or physical resource block (PRB) 107) is defined by Nsymb consecutive OFDM symbols 101 in the time domain and NRB consecutive subcarriers 108 in the frequency domain. That is, an RB 107 consists of Nsymb x NRB REs 106. Typically, the RB is the smallest data transmission unit. In LTE systems, Nsymb = 7, NRB = 12, and NBW and NRB are proportional to the system transmission bandwidth.

[0053] Next, a description of DCI for LTE and LTE-A systems is provided.

[0054] In LTE systems, DCI is used to transmit downlink or uplink data scheduling information from the eNB to the UE. Depending on the purpose—for example, indicating UL clearance for UL data scheduling or DL ​​clearance for DL ​​data scheduling, indicating the use of small-size control information, indicating whether spatial multiplexing based on multiple antennas is applied, and indicating the use of power control—DCI is classified into different DCI formats. For example, DCI format 1 for DL ​​clearance is configured to include at least the following information.

[0055] - Resource Allocation Type 0 / 1 Flag: The resource allocation type 0 / 1 flag indicates whether the resource allocation scheme is Type 0 or Type 1. Type 0 is used to allocate resources in units of RBGs using a bitmap scheme. In LTE systems, the basic unit of scheduling can be an RB represented by time-frequency domain resources, and an RBG can include multiple RBs and can be the basic unit of scheduling in a Type 0 scheme. Type 1 is used to allocate specific RBs within an RBG.

[0056] - Resource Block Allocation: Resource block allocation indicates the RBs allocated for data transfer. Resources can be determined based on system bandwidth and resource allocation scheme.

[0057] - Modulation and Coding Scheme (MCS): MCS indicates the modulation scheme used for data transmission and the size of the transport block to be transmitted.

[0058] - Hybrid Automatic Repeat Request (HARQ) process number: The HARQ process number indicates the process number of the HARQ.

[0059] - New Data Indicator: The new data indicator indicates whether the HARQ transfer is an initial transfer or a retransmission.

[0060] - Redundant Version: Redundant version indicates a redundant version of HARQ.

[0061] - Transmit Power Control (TPC) Commands for Physical Uplink Control Channel (PUCCH): TPC commands for PUCCH indicate power control commands used for PUCCH as an uplink control channel.

[0062] After undergoing channel coding and modulation processes, DCI can be transmitted on PDCCH or EPDCCH.

[0063] Cyclic Redundancy Check (CRC) is attached to the DCI message payload and scrambled using the UE's Radio Network Temporary Identifier (RNTI). Different types of RNTIs exist for different purposes of the DCI message, such as UE-specific data transmission, power control commands, and random access responses. That is, the RNTI is not explicitly transmitted but is included during the CRC calculation process. When a DCI message is received on the PDCCH, the UE performs a CRC check using the assigned RNTI, and if the CRC check is successful, determines that the message is addressed to itself.

[0064] Figure 2 This is a diagram showing PDCCH 201 and EPDCCH 202 as downlink physical channels carrying LTE DCI.

[0065] refer to Figure 2PDCCH 201 is time-division multiplexed (TDM) with the Physical Downlink Shared Channel (PDSCH) 203, which serves as a data channel, and extended across the entire system bandwidth. The control area used for transmitting PDCCH 201 can be represented by the number of OFDM symbols, indicated by the Control Format Indicator (CFI) transmitted to the UE in the Physical Control Format Indicator Channel (PCFICH). PDCCH 201 is mapped to several OFDM symbols at the beginning of the subframe, enabling the UE to quickly decode downlink scheduling information for decoding the Downlink Shared Channel (DL-SCH) without delay, resulting in a contribution to reducing downlink transmission latency. Assuming the PDCCH conveys a DCI message, when multiple UEs are scheduled in the downlink and uplink, it is possible that multiple UE PDCCHs are transmitted per cell. Cell-specific Reference Signal (CRS) 204 is used as the reference signal for decoding PDCCH 201. CRS 204 is spread across the entire system bandwidth and transmitted in each subframe with different scrambling and resource mappings determined by the cell identifier (ID). Because CRS 204 is a common reference signal used by all UEs within the cell, beamforming of CRS 204 cannot be performed in a UE-specific manner. Therefore, multi-antenna transmission of the LTE PDCCH is limited to open-loop transmission diversity. The number of CRS ports is implicitly communicated to the UE via Physical Broadcast Channel (PBCH) decoding.

[0066] Resource allocation for PDCCH 201 is performed based on Control Channel Elements (CCEs), and a CCE consists of 9 Resource Element Groups (REGs) – i.e., 36 REs. PDCCH 201 can be transmitted on 1, 2, 4, or 8 CCEs, and the number of CCEs depends on the channel coding rate of the DCI message payload. The reason for using different numbers of CCEs is to achieve link adaptation for PDCCH 201. The UE must detect PDCCH 201 without any information about it by blind decoding within a search space that is a set of CCEs. The search space is a group of CCEs consisting of an aggregation level (AL), which is implicitly determined based on a function of the UE identifier and subframe number, rather than explicitly signaled. The UE uses the CCEs within the search space to perform blind decoding of all possible available resource candidates to decode PDCCH 201 and processes information verified as valid for the UE through a CRC test.

[0067] There are two types of search spaces: UE-specific search space and common search space. A group of UEs or all UEs can monitor the common search space of PDCCH 201 to receive cell-specific control information, such as dynamic scheduling for system information and paging messages. For example, by decoding the common search space of PDCCH 201, it is possible to receive DL-SCH scheduling assignment information for transmitting System Information Block-1 (SIB-1), which includes operator information for the cell.

[0068] like Figure 2 As shown, EPDCCH 202 is frequency-multiplexed with PDSCH 203. The eNB can allocate resources appropriately for EPDCCH 202 and PDSCH 203 through scheduling to effectively support coexistence with data transmission to legacy LTE UEs. However, a problem arises as follows: EPDCCH 202 spanning a subframe contributes to transmission latency. It is possible that multiple EPDCCH 202s form an EPDCCH set, for which resources are allocated via PRB pairs. The EPDCCH set location is configured in a UE-specific manner, and the EPDCCH set location information is transmitted via Radio Resource Control (RRC) signaling. A UE can be assigned up to two EPDCCH sets, and one of the EPDCCH sets can be multiplexed with the EPDCCH sets of other UEs.

[0069] Resource allocation for EPDCCH 202 is performed based on Enhanced CCEs (ECCEs), where an ECCE consists of 4 or 8 Enhanced REGs (EREGs), and the number of EREGs per ECCE depends on the Cyclic Prefix (CP) length and subframe configuration information. An EREG consists of 9 REs, and up to 16 EREGs can exist per PRB pair. Depending on the EREG-to-RE mapping scheme, there are two different ways to transmit EPDCCH 202: "centralized" and "distributed." There are six possible ECCE aggregation levels: 1, 2, 4, 8, 16, and 32, selected based on CP length, subframe configuration, EPDCCH format, and transport scheme.

[0070] EPDCCH 202 is transmitted only within the UE-specific search space. Therefore, the UE must monitor the common search space used for PDCCH 201 to receive system information.

[0071] EPDCCH 202 carries a demodulation reference signal (DMRS) 205. The eNB can perform precoding on EPDCCH 202 and use UE-specific beamforming. The UE can decode EPDCCH 202 without notifying the precoding used for EPDCCH 202. EPDCCH 202 is configured with the same DMRS mode as PDSCH 203. However, DMRS 205 can support up to four antenna ports in EPDCCH 202, unlike PDSCH 203. DMRS 205 can be transmitted only in the PRB to which EPDCCH 202 is mapped.

[0072] The port configuration information for DMRS 205 varies depending on the EPDCCH transmission mode. In centralized transmission mode, the antenna port corresponding to the ECCE mapped to EPDCCH 202 is selected based on the UE ID. When multiple UEs share the same ECCE, i.e., in the case of multi-user MIMO transmission, DMRS antenna ports can be assigned to each UE. DMRS 205 can also be transmitted in a shared manner, and in this case, UEs can be distinguished using DMRS scrambling sequences configured via higher-layer signaling. In distributed transmission mode, up to two antenna ports can be supported for DMRS 205 and precoder-based cyclic diversity schemes. DMRS 205 mapped to REs within the same PRB pair can be shared.

[0073] In LTE, the entire PDCCH area consists of a set of CCEs in the logical domain, and there exists a search space composed of these CCEs. The search space is divided into a common search space and a UE-specific search space, and the search space used for LTE PDCCH is defined as shown in Table 1 below.

[0074] [Table 1]

[0075]

[0076] Based on the above definition of the search space for PDCCH, the UE-specific search space is defined as a function of the UE identifier and subframe number, rather than being explicitly signaled. That is, the UE-specific search space can change depending on the subframe, i.e., it changes over time. This allows us to overcome the problem that a search space being used by one UE can be prevented from being used by another user (the blocking problem). Although a UE cannot be scheduled in a subframe because all CCEs being searched by a UE in the same subframe are being used by another terminal, this problem may not occur in the next subframe because the search space changes over time. For example, although the UE-specific search spaces of UE#1 and UE#2 partially overlap in a certain subframe, because the UE-specific search space changes in each subframe, the UE can predict that the overlap may change in the next subframe.

[0077] Based on the above definition of the search space for PDCCH, the common search space is defined by a predetermined set of CCEs so that a group of UEs or all UEs can receive the corresponding PDCCH. That is, the common search space does not change based on the UE identifier or subframe number. Although the common search space is needed to transmit various system messages, it can also be used to transmit UE-specific control information. This indicates that when there are insufficient available resources for scheduling UEs in the UE-specific search space, the common search space can be used as a solution for scheduling UEs.

[0078] The search space is the set of control channel candidates corresponding to the CCEs that the UE attempts to decode for its control channels, and the UE has multiple search spaces for several aggregation levels as groups of CCEs. For LTE PDCCH, the number of PDCCH candidates monitored by the UE within the search space determined according to the aggregation level is listed in Table 2 below.

[0079] [Table 2]

[0080]

[0081] As shown in Table 2 above, the UE-specific search space is used at aggregation levels {1, 2, 4, 8} and has its own PDCCH candidate {6, 6, 2, 2}. The common search space is used at aggregation levels {4, 8} and has its own PDCCH candidate {4, 2}. The reason for using the common search space only at the two aggregation levels {4, 8} is to ensure good coverage, as system messages should reach the cell edge.

[0082] The DCI transmitted in the search space is defined only in certain DCI formats, such as DCI formats 0 / 1A / 3 / 3A / 1C for system information and transmit power control. In the common search space, DCI formats used for spatial multiplexing are not supported. The DCI format to be decoded in a UE-specific search space varies depending on the configured transmission mode. Since the transmission mode is configured via RRC signaling, no accurate subframe number is provided to determine whether the corresponding configuration is valid for the corresponding terminal. Therefore, regardless of the transmission mode, the UE always attempts to decode using DCI format 1A to maintain communication.

[0083] The above provides a description of the downlink control channel and control information transmission / reception methods, as well as the search space for traditional LTE and LTE-A.

[0084] The downlink control channel for 5G communications, which is currently under discussion, is described below with reference to the accompanying drawings.

[0085] Figure 3 This is a diagram illustrating the basic unit 300 of the time and frequency resources of the downlink control channel in a 5G system. (Reference) Figure 3 The REG, which serves as the basic unit of time and frequency resources for the control channel, consists of one OFDM symbol 301 in the time domain and 12 subcarriers 302 (i.e., one RB) in the frequency domain. By assuming one OFDM symbol as the basic unit of control channel resources in the time domain, data and control channels can be multiplexed within a single subframe. The control channel is followed by the data channel to reduce processing time at the UE, thereby facilitating the fulfillment of latency requirements. By using one RB 302 as the basic unit of control channel resources in the frequency domain, frequency multiplexing of control and data channels can be facilitated.

[0086] By concatenating multiple REGs, various control channel regions of different sizes can be configured. For example, assuming the basic unit for downlink control channel resource allocation in 5G is CCE 304, then CCE 304 can be composed of multiple REGs. Figure 3 The REG 303 depicted consists of 12 REs, and assuming a CCE consists of 6 REs, then a CCE 304 consists of 72 REs. If a downlink control area is configured, the control area can consist of multiple CCEs 304, and a downlink control channel can be mapped to one or more CCEs based on the AL in the control area. The CCEs constituting the control area are distinguished by CCE numbers, which are assigned in a logical mapping manner.

[0087] The basic unit of downlink control channel resources, namely Figure 3 The REG 303 depicted may include the RE to which the DCI is mapped and the RE to which the DMRS 305, serving as a reference signal for decoding the DCI, is mapped. The number of antenna ports used to transmit the downlink control channel can be considered when mapping the DMRS 305. Figure 3 The scenario using two antenna ports is described. DMRS 306 and DMRS 307 can be transmitted separately for antenna port #0 and antenna port #1, respectively. DMRS for different antenna ports can be multiplexed in various ways. Figure 3 This describes the case where DMRS used for different antenna ports are mapped to different REs to maintain orthogonality. For example... Figure 3 As described, DMRS can be either Frequency Division Multiplexing (FDMed) or Code Division Multiplexing (CDMed). DMRS can be configured in various DMRS modes in association with the number of antenna ports.

[0088] Figure 4 This is a diagram illustrating how CORESET is configured to transmit downlink control channels in a 5G wireless communication system according to embodiments of the present disclosure. Figure 4 The time-frequency resource structure is shown, which includes a system bandwidth of 410 in frequency and a time slot of 420 in time. Figure 4 In this embodiment, assuming one time slot consists of 7 OFDM symbols, it includes two CORESETs, namely CORESET #1 401 and CORESET #2 402. CORESET #1 401 and CORESET #2 402 can be configured in the frequency domain within certain subbands 403 of the system bandwidth 410. A CORESET can span one or more OFDM symbols in the time domain and can be referred to as the control resource set duration 404.

[0089] The base station can configure the 5GCORESET to the terminal via higher-layer signaling (e.g., system information, Master Information Block (MIB), and RRC signaling). If the terminal has a CORESET configured, this instructs the base station to provide the terminal with information about the CORESET location, subband, CORESET resource allocation, and CORESET length. This configuration information may include the information listed in Table 3 below.

[0090] [Table 3]

[0091]

[0092] In addition to the information mentioned above, it is also possible to configure the terminal with other information necessary for transmitting the downlink control channel.

[0093] Figure 5 This is a diagram illustrating 5G timeslot format 500.

[0094] refer to Figure 5 In 5G, a time slot 501 can consist of 14 OFDM symbols 502. Time slot 501 can also consist of downlink symbols 503, uplink symbols 505, and an unknown symbol 504. If the symbol is a downlink symbol 503, it indicates that transmission has occurred in the direction from the base station to the terminal; that is, during the corresponding symbol period, the base station transmits and the terminal receives. If the symbol is an uplink symbol 505, it indicates that transmission has occurred in the direction from the terminal to the base station; that is, during the corresponding symbol period, the terminal transmits and the base station receives. If the symbol is an unknown symbol 504, it indicates that there may be no transmission between the base station and the terminal during the corresponding symbol period. However, the unknown symbol 504 can be overridden by another DCI, and in this case, the unknown symbol 504 can be used for a specific purpose as indicated by the DCI's indicator.

[0095] A time slot can consist of an uplink symbol 505, a downlink symbol 503, and an unknown symbol 504, and a certain combination of the uplink symbol 505, downlink symbol 503, and unknown symbol 504 can be called a time slot format. That is, each of the 14 symbols constituting a time slot can be one of the uplink symbol 505, downlink symbol 503, and unknown symbol 504, and the possible number of time slot formats can become 314. Figure 5 This is a diagram illustrating an exemplary time slot format, wherein symbols 1 to 6 are downlink symbols 503, symbols 7 to 9 are unknown symbols 504, and symbols 10 to 14 are uplink symbols 505.

[0096] The base station can notify the terminal of the time slot format via a Time Slot Format Indicator (SFI). The SFI can be transmitted on the Group Common PDCCH. The Group Common PDCCH can convey one or more SFIs, which can indicate different time slot formats for sequentially following time slots. The base station can configure the terminal to monitor the Group Common PDCCH, and in this case, the terminal can monitor the Group Common PDCCH to obtain SFIs. Based on the obtained SFIs, the terminal can obtain the time slot format of one or more specific time slots, and determine whether each symbol is a downlink symbol 503, an uplink symbol 505, or an unknown symbol 504 based on the obtained time slot format.

[0097] The following describes the method for transmitting DMRS, which is considered necessary for decoding PDSCH, in 5G communication systems.

[0098] Figure 6This is a diagram of a method believed to be used in 5G communication systems for transmitting DMRS necessary for decoding PDCCH.

[0099] refer to Figure 6 In 5G communication systems, the location of the DMRS varies depending on the PDSCH mapping type. Figure 6 In the figures, reference numeral 610 indicates PDSCH mapping type A corresponding to slot-based scheduling, while reference numeral 620 indicates PDSCH mapping type B corresponding to non-slot-based or mini-slot-based scheduling. Slot-based scheduling is characterized by scheduling PDSCH on one slot 600, while non-slot-based or mini-slot-based scheduling is characterized by scheduling PDSCH on mini-slots 608 configured with a predetermined number of symbols.

[0100] 5G communication systems support two types of DMRS: First DMRS 601 (or front-loaded DMRS) and Second DMRS 602 (or supplementary DMRS). First DMRS 601 is introduced in 5G to reduce processing time by enabling rapid channel estimation for PDSCH decoding. Second DMRS 602 is introduced in 5G for improved channel estimation performance, phase distortion compensation, and tracking of fast-moving terminals. Transmitting First DMRS 601 for PDSCH decoding is unavoidable, and Second DMRS 602 can be transmitted additionally depending on the base station configuration. Second DMRS 602 can be transmitted repeatedly in the same mode as First DMRS 601. The symbol position used for transmitting First DMRS 601 can vary depending on the PDSCH mapping type. In the case of PDSCH mapping type A 610, First DMRS 601 can be transmitted at the third OFDM symbol (or fourth OFDM symbol). In the case of PDSCH mapping type B 620, the first DMRS 601 can be transmitted at the first OFDM symbol of the resource scheduled for PDSCH. The symbol location for transmitting the second DMRS 602, which is still under discussion, can be fixed or configured by the base station and is notified to the terminal via DCI.

[0101] 5G communication systems support two types of DMRS, and the DMRS type determines the number of ports and the DMRS transmission mode. In DMRS type 1, up to 4 ports can be supported for 1 OFDM symbol transmission and up to 8 ports for 2 OFDM symbol transmission. In DMRS type 2, up to 6 ports can be supported for 1 OFDM symbol transmission and up to 12 ports for 2 OFDM symbol transmission. That is, the maximum number of DMRS ports that can be supported depends on the number of OFDM symbols used for DMRS transmission.

[0102] exist Figure 6 In the embodiments, PDSCH mapping type A 610 is characterized by a first DMRS 601 that maps to the third OFDM symbol 604 and the fourth OFDM symbol 605 respectively, and a second DMRS 602 that maps to the tenth OFDM symbol 606 and the eleventh OFDM symbol 607 respectively.

[0103] The following section describes the BWP configuration method considered to be used in 5G communication systems.

[0104] Figure 7 This is a diagram illustrating an exemplary configuration of the BWP 700 in a 5G communication system.

[0105] refer to Figure 7 The terminal bandwidth 750 is divided into two BWPs, namely BWP#1 701 and BWP#2 702. The base station can configure one or more BWPs to the terminal, and each BWP is configured with the information listed in Table 4 below.

[0106] [Table 4]

[0107]

[0108] In addition to the configuration information described above, other BWP-related parameters can be configured for the terminal. The base station can transmit this information to the terminal via higher-layer signaling (e.g., RRC signaling). At least one of the configured BWPs can be activated. The base station can semi-statically transmit information indicating whether to activate the BWP to the terminal via RRC signaling, a Media Access Control (MAC) control element (CE), or a DCI.

[0109] In 5G, BWP can be configured for various purposes.

[0110] For example, it is possible to configure the BWP for situations where the system bandwidth is wider than the bandwidth supported by the terminal. The terminal can transmit data at a frequency position within the system bandwidth by configuring the frequency position of the BWP to the terminal's example (configuration information 2 in Table 4 above).

[0111] For example, to support different parameter sets, a base station can configure multiple Base-Wide Platforms (BWPs) for a terminal. For instance, to enable a terminal to support data communication with two subcarrier intervals of 15 kHz and 30 kHz, two BWPs with different subcarrier intervals of 15 kHz and 30 kHz can be configured. Frequency division multiplexing (FDMed) can be performed on BWPs with different subcarrier intervals, and if data communication with a specific subcarrier interval is required, the BWP configured with the corresponding subcarrier interval can be activated.

[0112] For example, to reduce terminal power consumption, a base station can configure multiple BWPs with different bandwidths for the terminal. For instance, if a terminal supporting a very wide bandwidth (e.g., 100MHz) always performs data communication via the corresponding bandwidth, this can lead to significant power consumption. For example, given the power consumption, monitoring an unnecessary downlink control channel with a wide bandwidth of 100MHz when there is no service is highly inefficient. To further reduce terminal power consumption, the base station can configure the BWP to a relatively narrow BWP, such as a 20MHz BWP. In this case, the terminal can monitor the 20MHz BWP when there is no service, and if data needs to be transmitted / received or a command is received from the base station, the terminal can transmit / receive data using the 100MHz BWP.

[0113] This disclosure relates to a method and apparatus for transmitting and receiving downlink control and data channels in a wireless communication system.

[0114] As described above, 5G communication systems can support both PDSCH mapping type A (or slot-based scheduling) and PDSCH mapping type B (or non-slot-based scheduling). The DMRS location can vary depending on the scheduling scheme (i.e., slot-based scheduling and non-slot-based scheduling). Therefore, it is necessary to share information in advance between the base station and the terminal regarding whether slot-based or non-slot-based scheduling is used. This disclosure provides a method for a base station to notify a terminal of the scheduling scheme (slot-based / non-slot-based scheduling) to be used, and a method for terminal operation based on the scheduling scheme notification.

[0115] As described above, in 5G, SFI can be transmitted on a group common PDCCH. In this case, the base station can notify the terminal via additional DCI of the purpose of using the unknown symbol in a time slot including downlink, uplink, and unknown symbols. The terminal can use the unknown symbol for the purpose indicated by the indicator received from the base station. This disclosure provides additional signaling for indicating the purpose of the unknown symbol (e.g., downlink transmission, uplink transmission, gap, and measurement), as well as the operation of the base station and the terminal based on the purpose of the unknown symbol.

[0116] In 5G, certain time / frequency resources can be configured as reserved resources for various purposes. Base stations and terminals cannot use these reserved resources for communication. Reserved resources can be used to ensure forward compatibility and can be configured with the highest priority on any time and frequency resources, as determined by the base station. This disclosure provides a method for a base station to transmit downlink control information and a terminal to monitor the CORESET of downlink control information when a portion of the CORESET, designed for transmitting downlink control channels, is configured as a reserved resource.

[0117] Embodiments of this disclosure are described in detail below with reference to the accompanying drawings. Although the description is directed to LTE or LTE-A systems, those skilled in the art will understand that this disclosure can be applied to other communication systems with similar technical backgrounds and channel formats. For example, this disclosure is applicable to 5G communication systems (5G New Radio (NR)) developed after LTE-A. Therefore, those skilled in the art will understand that this disclosure can be applied to other communication / computing systems with minor modifications without departing from the scope and spirit of this disclosure.

[0118] To avoid obscuring the subject matter of this disclosure, detailed descriptions of well-known functions and structures incorporated herein have been omitted. Furthermore, the following terms are defined in consideration of the functions in this disclosure, and these terms may vary depending on the intent, usage, etc., of the user or operator. Therefore, definitions should be based on the overall content of this disclosure.

[0119] Example 1

[0120] Example 1 relates to a method and apparatus for supporting PDSCH scheduling schemes (i.e., PDSCH mapping type A (time slot-based scheduling) and PDSCH mapping type B (non-time slot-based scheduling)).

[0121] The base station can configure PDSCH mapping type A or PDSCH mapping type B to the terminal via higher-layer signaling (e.g., system information, cell-specific RRC signaling, UE-specific RRC signaling, and MAC CE). If the base station configures PDSCH mapping type A to the terminal, the base station can transmit the first DMRS at the 3rd or 4th OFDM symbol. If the base station configures PDSCH mapping type B to the terminal, the base station can transmit the first DMRS at the first symbol in the resources scheduled for the corresponding PDSCH.

[0122] The terminal can receive configuration information indicating PDSCH mapping type A or PDSCH mapping type B from the base station via higher-layer signaling (e.g., system information, cell-specific RRC signaling, UE-specific RRC signaling, and MAC CE). If PDSCH mapping type A is configured for the terminal, the terminal can receive the first DMRS at the 3rd or 4th OFDM symbol. If PDSCH mapping type B is configured for the terminal, the terminal can receive the first DMRS at the first OFDM symbol of the resources scheduled for PDSCH.

[0123] The following describes the method for configuring PDSCH mapping type A or PDSCH mapping type B from a base station to a terminal.

[0124] Example 1-1

[0125] In Example 1-1, the base station can configure the PDSCH mapping type A or B for each BWP to the terminal.

[0126] The base station can configure the PDSCH mapping type (PDSCH mapping type A or B) of each BWP to the terminal via a part of the BWP configuration.

[0127] The base station can transmit configuration information to the terminal via higher-layer signaling (e.g., UE-specific RRC signaling and MAC CE signaling).

[0128] That is, the base station can configure the PDSCH mapping type for each BWP to the terminal. Specifically, the base station can configure BWP#1 and BWP#2 to the terminal. The configuration information for each BWP can determine the corresponding PDSCH mapping type for the BWP. For example, it may be possible to configure each of BWP#1 and BWP#2 using PDSCH mapping type A or B.

[0129] If the base station configures PDSCH mapping type A to a BWP of the terminal, the base station can transmit the first DMRS at the 3rd or 4th OFDM symbol in the PDSCH of the corresponding BWP. If the base station configures PDSCH mapping type B to a specific BWP of the terminal, the base station can transmit the first DMRS at the 1st OFDM symbol in the resources scheduled for the PDSCH of the corresponding BWP.

[0130] The terminal can receive the PDSCH mapping type for each BWP from the base station.

[0131] The terminal can receive information indicating the PDSCH mapping type of the corresponding BWP via a part of the BWP configuration.

[0132] The terminal can determine the DMRS position in the PDSCH scheduled in the corresponding BWP based on configuration information indicating the specific PDSCH mapping type of the BWP. If a BWP is configured with PDSCH mapping type A, the terminal can receive the first DMRS at the 3rd or 4th OFDM symbol in the corresponding BWP. If a BWP is configured with PDSCH mapping type B, the terminal can receive the first DMRS at the 1st OFDM symbol of the resource scheduled for the PDSCH of the corresponding BWP.

[0133] According to Embodiment 1-1, this method is advantageous in that it enables the configuration of multiple PDSCH mapping types to a terminal in a BWP-specific manner. This indicates that the terminal can be configured with both PDSCH mapping types A and B simultaneously. For example, if BWP#1 and BWP#2 are configured with PDSCH mapping types A and B respectively, the base station can schedule PDSCH transmissions in BWP#1 with PDSCH mapping type A and in BWP#2 with PDSCH mapping type B.

[0134] In Example 1-1, BWP can be replaced with component carriers in carrier aggregation (CA). That is, the base station can configure the PDSCH mapping type for each component carrier to the terminal, and the terminal can determine the PDSCH reception scheme for each carrier based on the configuration information.

[0135] Examples 1-2

[0136] In Examples 1-2, the base station can configure the PDSCH mapping type (PDSCH mapping type A or B) for each CORESET to the terminal for PDSCH scheduled via DCI transmitted on the corresponding CORESET.

[0137] The base station can also use a portion of the configuration information for the CORESET used to carry the downlink control channel to configure the PDSCH mapping type (PDSCH mapping type A or B) for each CORESET for PDSCH scheduled via DCI transmitted on the corresponding CORESET.

[0138] The base station can transmit configuration information to the terminal via higher-layer signaling (e.g., UE-specific RRC signaling and MAC CE signaling).

[0139] The base station can configure one or more CORESETs to the terminal via higher-layer signaling (e.g., MIB, SIB, and RRC signaling). For example, the base station can configure CORESET #1 and CORESET #2 to the terminal. The base station can also configure the terminal with: PDSCH mapping type A for PDSCH scheduled via DCI transmitted on CORESET #1 and PDSCH mapping type B for PDSCH scheduled via DCI transmitted on CORESET #2.

[0140] If a base station wants to transmit a PDSCH to a terminal in PDSCH mapping type A, the base station can transmit a DCI containing scheduling information for the corresponding PDSCH in a CORESET configured in association with PDSCH mapping type A, and in this case, a first DMRS for decoding the corresponding PDSCH can be transmitted at the 3rd or 4th OFDM symbol.

[0141] If a base station wants to transmit a PDSCH to a terminal in PDSCH mapping type B, the base station can transmit a DCI containing scheduling information for the corresponding PDSCH in a CORESET configured with PDSCH mapping type B. In this case, a first DMRS for decoding the corresponding PDSCH can be transmitted at the first OFDM symbol in the resource scheduled for the corresponding PDSCH.

[0142] The terminal can receive configuration information from the base station, which indicates whether the PDSCH mapping type for each CORESET used for PDSCH scheduled via DCI transmitted on the corresponding CORESET is PDSCH mapping type A or B.

[0143] The terminal can also receive configuration information that uses a portion of the CORESET configuration information that conveys the downlink control channel to indicate whether the PDSCH mapping type used for PDSCH scheduled via DCI transmitted on the corresponding CORESET is PDSCH mapping type A or B.

[0144] The terminal can receive configuration information about one or more CORESETs via higher-level scheduling (e.g., MIB, SIB, and RRC signaling). The terminal can perform blind decoding to decode the DCI in the configured CORESET.

[0145] If the UE obtains a DCI conveying PDSCH scheduling information in a CORESET configured with PDSCH mapping type A, then under the assumption of PDSCH mapping type A, the UE can receive the first DMRS for decoding the corresponding PDSCH at the 3rd or 4th OFDM symbol. As a result, the terminal can receive and decode the PDSCH based on the scheduling information carried in the DCI.

[0146] If the UE obtains a DCI conveying PDSCH scheduling information in a CORESET configured with PDSCH mapping type B, then under the assumption of PDSCH mapping type B, the UE can receive the first DMRS for decoding the corresponding PDSCH at the first OFDM symbol in the resource scheduled for the corresponding PDSCH. As a result, the terminal can receive and decode the PDSCH based on the scheduling information carried in the DCI.

[0147] According to embodiments 1-2, this method is advantageous in terms of enabling the configuration of multiple PDSCH mapping types to a terminal. This indicates that the terminal can be configured with both PDSCH mapping types A and B simultaneously. Furthermore, this method is advantageous in maximizing scheduling flexibility by scheduling PDSCH using both PDSCH mapping types A and B across the entire bandwidth of the terminal, not limited to any specific frequency band within the terminal bandwidth. For example, when CORESET #1 and CORESET #2 are configured respectively with PDSCH mapping types A and B, the base station can transmit one DCI for PDSCH scheduling to the terminal in CORESET #1 associated with PDSCH mapping type A, and another DCI for PDSCH scheduling to the terminal in CORESET #2 associated with PDSCH mapping type B.

[0148] In embodiments 1-2, CORESET can be replaced with search space (or sub-search space). That is, the base station can configure the PDSCH mapping type for each search space within CORESET, and the terminal can determine the PDSCH mapping type for scheduling PDSCH based on the configuration information and the DCI of each search space in CORESET.

[0149] Examples 1-3

[0150] In Examples 1-3, each PDSCH mapping type defines the DCI format.

[0151] For example, it may be possible to define DCI format A for scheduling PDSCHs associated with PDSCH mapping type A and DCI format B for scheduling PDSCHs associated with PDSCH mapping type B.

[0152] DCI format A and B can be different sizes.

[0153] DCI formats A and B can use different RNTI scrambling methods. For example, DCI format A can use Ca-RNTI scrambling, while DCI format B can use Cb-RNTI scrambling.

[0154] The base station can be configured to monitor DCI format A corresponding to PDSCH mapping type A, DCI format B corresponding to PDSCH mapping type B, or both DCI formats A and B.

[0155] The base station can transmit the corresponding configuration information to the terminal via higher-layer signaling (e.g., UE-specific RRC signaling and MAC CE signaling).

[0156] If a base station wants to transmit a PDSCH of PDSCH mapping type A to a terminal, the base station can transmit scheduling information about the corresponding PDSCH to the terminal in DCI format A corresponding to PDSCH mapping type A. In this case, the first DMRS for decoding the corresponding PDSCH can be transmitted at the 3rd or 4th OFDM symbol.

[0157] If a base station wants to transmit a PDSCH of PDSCH mapping type B to a terminal, it can transmit scheduling information about the corresponding PDSCH to the terminal in DCI format B corresponding to PDSCH mapping type B. In this case, the first DMRS for decoding the corresponding PDSCH can be transmitted at the first OFDM symbol in the resource scheduled for the corresponding PDSCH.

[0158] The terminal can receive configuration information transmitted by the base station to configure the terminal to monitor DCI format A corresponding to PDSCH mapping type A, DCI format B corresponding to PDSCH mapping type B, or both DCI formats A and B. The base station can transmit the configuration information to the terminal via higher-layer signaling (e.g., UE-specific RRC signaling and MAC CE signaling).

[0159] The terminal can receive configuration information transmitted by the base station via higher-layer signaling (e.g., MIB, SIB, and RRC signaling) to configure the terminal to configure one or more CORESETs. The terminal can perform blind decoding to determine the DCI in the configured CORESET. The terminal can perform blind decoding in (one or more) CORESETs based on the configuration information for DCI format A, DCI format B, or both DCI formats A and B.

[0160] If the terminal detects DCI format A, it can assume that the PDSCH is transmitted via the corresponding DCI schedule with PDSCH mapping type A, and then perform decoding on the corresponding PDSCH to receive the first DMRS at the 3rd or 4th OFDM symbol. As a result, the terminal can receive and decode the PDSCH based on the scheduling information in the DCI.

[0161] If the terminal detects DCI format B, it can assume that the PDSCH is transmitted via the corresponding DCI schedule with PDSCH mapping type B, and then receive the first DMRS for decoding the corresponding PDSCH at the first OFDM symbol in the resource scheduled for the corresponding PDSCH. As a result, the terminal can receive and decode the PDSCH based on the scheduling information in the DCI.

[0162] In embodiments 1-3, it is possible to configure both PDSCH mapping types A and B simultaneously. For example, if the base station configures the terminal to monitor both DCI formats A and B, the base station can transmit scheduling information in DCI format A when PDSCH is transmitted to the corresponding terminal using PDSCH mapping type A; and transmit scheduling information in DCI format B when PDSCH is transmitted to the corresponding terminal using PDSCH mapping type B. According to embodiments 1-3, this method is advantageous in that it maximizes scheduling flexibility by scheduling PDSCH using both PDSCH mapping types A and B throughout the entire bandwidth of the terminal, and not limited to any specific frequency band in the terminal bandwidth. Furthermore, this method is advantageous in that it supports both PDSCH mapping types A and B without additional CORESET configuration.

[0163] Examples 1-4

[0164] In embodiments 1-4, the base station can configure the PDSCH mapping type (PDSCH mapping type A or B) to the terminal via a portion of the configuration information about the first DMRS.

[0165] The base station can transmit configuration information to the terminal via higher-layer signaling (e.g., terminal-specific RRC signaling and MAC CE signaling).

[0166] If the base station configures PDSCH mapping type A to the terminal in association with the first DMRS, the base station can transmit PDSCH to the terminal with PDSCH mapping type A, such that the first DMRS for receiving PDSCH is mapped to the third or fourth OFDM symbol.

[0167] If the base station configures PDSCH mapping type B to the terminal in association with the first DMRS, the base station can transmit PDSCH to the terminal with PDSCH mapping type B, such that the first DMRS mapping for receiving PDSCH is mapped to the first OFDM symbol in the resource corresponding to the PDSCH scheduling.

[0168] The terminal can receive configuration information transmitted by the base station, which is used to configure the terminal using a portion of the configuration information about the first DMRS, employing PDSCH mapping type A or B.

[0169] If the terminal is configured with a PDSCH mapping type A associated with the first DMRS, then under the assumption that the PDSCH is transmitted with PDSCH mapping type A, the terminal can receive the first DMRS for receiving the corresponding PDSCH at the 3rd or 4th OFDM symbol.

[0170] If the terminal is configured with a PDSCH mapping type B associated with the first DMRS, then under the assumption that the PDSCH is transmitted with PDSCH mapping type B, the terminal can receive the first DMRS for receiving the corresponding PDSCH at the first OFDM symbol in the resource scheduled for the corresponding PDSCH.

[0171] Examples 1-5

[0172] In Examples 1-5, the PDSCH mapping type (i.e., PDSCH mapping type A or B) is implicitly determined based on system parameters.

[0173] For example, the PDSCH mapping type can be implicitly determined based on the PDCCH monitoring period.

[0174] The base station can configure the PDCCH monitoring period for the terminal via higher-layer signaling (e.g., RRC signaling). To configure PDCCH mapping type A, the base station can set the terminal's PDCCH monitoring period T to a value greater than or equal to a predetermined threshold η. To configure PDCCH mapping type B, the base station can set the terminal's PDCCH monitoring period T to a value less than the threshold.

[0175] The terminal can receive configuration information, including the PDSCH monitoring period, from the base station via higher-layer signaling (e.g., RRC signaling). If the PDSCH monitoring period T is set to a value greater than or equal to a threshold η, the terminal can assume PDSCH mapping type A. If the PDSCH monitoring period T is set to a value less than the threshold η, the terminal can assume PDSCH mapping type B.

[0176] The threshold η can be a system parameter set to a fixed value, such as a time slot and a subframe.

[0177] Alternatively, the PDSCH mapping type can be determined based on the time pattern used to monitor the PDCCH.

[0178] The base station can configure the time pattern for PDCCH monitoring to the terminal via higher-layer signaling (e.g., RRC signaling). In this case, the time pattern for PDCCH monitoring can be defined as the index of the symbol or time slot for performing PDCCH monitoring.

[0179] To configure PDSCH mapping type A, the base station can configure a time pattern for PDCCH monitoring on a time slot basis for the terminal. That is, the base station can configure a set of time slot indexes indicating the time slots for which PDCCH monitoring is performed. For example, the PDCCH monitoring mode can be configured to perform PDCCH monitoring in time slots 1, 3, 5, and 7 out of 10 time slots.

[0180] To configure PDSCH mapping type B, the base station can configure a time pattern for PDCCH monitoring mode on a symbol-by-symbol basis for the terminal. That is, the base station can configure a symbol index set indicating the symbols for which PDCCH monitoring is performed. For example, the PDCCH monitoring mode can be configured to perform PDCCH monitoring on the 1st, 3rd, 5th, and 7th OFDM symbols out of 14 symbols.

[0181] The terminal can receive configuration information from the base station via higher-layer signaling (e.g., RRC signaling) indicating the time mode used for PDCCH monitoring. If the time mode used for PDCCH monitoring is configured to be in time slots, the terminal can assume PDSCH mapping type A. If the time PDCCH monitoring mode is configured to symbol mode, the terminal can assume PDSCH mapping type B.

[0182] Examples 1-6

[0183] In Examples 1-6, the PDSCH mapping type is dynamically notified to the terminal via DCI.

[0184] The base station can notify the terminal of the PDSCH mapping type (PDSCH mapping type A or B) used for transmitting PDSCH via the DCI that schedules the PDSCH. For example, the base station can use a 1-bit indicator included in the DCI to notify the terminal of the PDSCH mapping type. The terminal can check the indicator field indicating the PDSCH mapping type in the received DCI to determine whether the PDSCH mapping type used for transmitting the PDSCH scheduled via the DCI is PDSCH type A or B.

[0185] Example 2

[0186] Example 2 addresses a dynamic TDD method based on slot format indicators and a method for using unknown symbols for certain uses of slot formats in 5G.

[0187] Example 2-1

[0188] Figure 8 This is a diagram of the dynamic TDD method based on time slot format indicators according to Embodiment 2-1.

[0189] refer to Figure 8 The figure shows 10 time slots 800 with a length indicated by reference numeral 805.

[0190] A specific timeslot can be a fixed timeslot 801. The timeslot of a fixed timeslot 801 is not changed by any additional configuration of the base station and is located at certain points in time (or timeslot indexes) agreed upon between the base station and the terminal. In Embodiment 2-1, timeslots 0 and 5 are shown as fixed timeslots 801. The reason for supporting fixed timeslots 801 is to transmit signals periodically, regardless of the timeslot format used by the system. For example, it may be possible to define a fixed timeslot 801 for transmitting a synchronization signal block (SSB), which is always transmitted periodically in the system.

[0191] A time slot can be a semi-statically configured time slot 802. The base station can configure certain time slots in a certain time slot format and transmit the corresponding configuration information to the terminal via higher-layer scheduling (e.g., system information (SI) and RRC signaling). In Embodiment 2-1, time slots 2 and 8 are depicted as semi-statically configured time slots 802.

[0192] A time slot can be a flexible time slot 803. Although the time slot 803 is referred to as a flexible time slot in this embodiment, it can be referred to as a dynamic time slot or an unknown time slot. The base station can determine the time slot used in the flexible time slot 803 and notify the terminal of the flexible time slot 803 via higher-layer signaling (e.g., SI or RRC signaling). In embodiment 2-1, time slots 1, 3, 4, 6, 7, and 9 are flexible time slots 803.

[0193] The base station can transmit SFIs with flexible timeslot 803 format to the terminal via the group common DCI.

[0194] The base station can configure the terminal to monitor the Group Common DCI at a time slot configured with flexible time slot 803 via higher-layer signaling (e.g., RRC signaling and MAC CE signaling). For example, assuming the Group Common DCI transmitting the SFI is scrambled with a certain RNTI (e.g., SFI-RNTI), the base station can configure the terminal to monitor the Group Common DCI configured with SFI-RNTI. The base station can also configure the terminal to specify the monitoring period and monitoring time pattern for the Group Common DCI. Figure 8 As shown, the base station can configure the terminal to perform group common DCI monitoring in time slots 1, 3, 4, 6, 7, and 9, with 10 time slots in a time period. In this case, the SFI can indicate the time slot format of one or more time slots. For example, the SFI can indicate the time slot format of the time slot carrying the corresponding SFI, or indicate a time slot format of 5 time slots including the time slot carrying the SFI and 4 time slots following that time slot carrying the SFI. The base station can notify the terminal of the number of time slots in the time slot format indicated by the SFI via higher-layer signaling (e.g., RRC signaling and MAC CE signaling).

[0195] The terminal can receive configuration information transmitted by the base station to configure itself to monitor the group common DCI. The terminal can also receive configuration information transmitted by the base station to configure the monitoring period and monitoring time mode for the group common DCI. The terminal can also receive configuration information transmitted by the base station to notify the terminal of the number of time slots in the time slot format indicated by the SFI included in the group common DCI. The terminal can monitor the group common DCI carrying the SFI according to the configuration information received from the base station to obtain time slot format information about one or more time slots based on the received SFI.

[0196] Example 2-2

[0197] As described above, a time slot can consist of downlink, uplink, and unknown symbols, and the combination of downlink, uplink, and unknown symbols is called a time slot format. Symbols designated as unknown symbols can be rewritten in the DCI transmitted from the base station to the terminal. If an unknown symbol is rewritten in the DCI, this indicates that the symbol designated as unknown via the DCI is used for a specific purpose (e.g., downlink, uplink, gap, and measurement), as indicated by the indicators included in the DCI. The term "gap" indicates the handover time required for the terminal to switch from downlink reception to uplink transmission. The term "measurement" indicates the operations performed by the terminal for the following: channel measurements (e.g., Channel State Information (CSI) measurement), power measurements (Reference Signal Received Power (RSRP) measurement), Reference Signal Received Quality (RSRQ) measurement, and Reference Signal Strength Indicator (RSSI) measurement. Example 2-2 pertains to a method for utilizing unknown symbols as indicated via the SFI.

[0198] Figure 9 This is a diagram of the method for utilizing unknown symbols according to Example 2-2.

[0199] refer to Figure 9 Time slot 950 consists of 14 OFDM symbols, and the length of each OFDM symbol is indicated by reference numeral 901 in the attached figure.

[0200] The base station can transmit the SFI to the terminal via the group common DCI. The terminal can obtain time slot format information about the corresponding time slot from the received SFI. That is, the time slot can be configured as a combination of downlink, uplink, and unknown symbols. For example, Figure 9 A time slot format 902 is depicted, consisting of symbols 1, 2, 4, 5, and 6 as downlink symbols, symbols 10, 11, 12, 13, and 14 as uplink symbols, and symbols 3, 7, 8, and 9 as unknown symbols, as indicated via the SFI. A terminal group receiving the same group common DCI can receive the same SFI, and all terminals belonging to that group are assumed to use the same time slot format for their corresponding time slots.

[0201] The base station can also transmit an indicator to the terminal indicating the purpose of the unknown symbol 917. Specifically, the base station can transmit the indicator to the terminal via a UE-specific DCI, which indicates the purpose of the unknown symbol 917 as one of downlink, uplink, gap, and measurement purposes.

[0202] The following describes a method for using the unknown symbol 917 for measurements as indicated by reference numeral 918. This method can be applied to situations where the unknown symbol 917 is used for downlink, uplink, and gaps in the same manner.

[0203] The base station can instruct the terminal via UE-specific DCI to perform a measurement at an unknown symbol 917. In Embodiment 2-2, the base station can instruct UE#1 903 to perform a measurement 918 at the third OFDM symbol, which is designated as one of the unknown symbols 917 via UE-specific DCI as shown by reference numeral 905. The base station can also instruct UE#2 904 to perform a measurement 918 at the seventh OFDM symbol, which is designated as one of the unknown symbols 917 via UE-specific DCI as shown by reference numeral 906.

[0204] The base station can use N bits (N=1) of the UE-specific DCI to indicate one or more unknown symbols 917 to be used for measurement 918.

[0205] For example, the base station can use N=1 bits to instruct the terminal to perform measurements at all unknown symbols 917. That is, when symbols 3, 7, 8, and 9 are designated as unknown symbols 917, the base station can transmit a 1-bit indicator to the terminal indicating whether to perform measurements 918 at all unknown symbols (i.e., symbols 3, 7, 8, and 9).

[0206] For example, a base station can use N bits (N=1) to group the symbol designated as unknown symbol 917 into units (one or more symbols) for a terminal, and indicate the unknown symbol group used for measurement. If the number of unknown symbols is M, and N bits are used to indicate whether a measurement is performed, the M unknown symbols can be divided into N unknown symbol groups, each with ceil(M / N) unknown symbols. The base station can use an N-bit bitmap to indicate the unknown symbol group used for measurement 918 among the N unknown symbol groups.

[0207] refer to Figure 9 Let's elaborate on the description. For example, M (M=4) OFDM symbols, namely the 3rd, 7th, 8th, and 9th OFDM symbols, are unknown symbols, and N bits (N=2) are used to indicate the unknown symbols used for measurement. In this case, the set of unknown symbols can be divided into two groups of unknown symbols. For example, the unknown symbols can be grouped into unknown symbol group #1 {the 3rd symbol, the 7th symbol} and unknown symbol group #2 {the 8th symbol, the 9th symbol}. The base station can use a 2-bit bitmap indicator to indicate that at least one of unknown symbol group #1 and unknown symbol group #2 is used in measurement 918. The indicator can be set as listed in Table 5 below.

[0208] [Table 5]

[0209]

[0210] The size (i.e., N) of the indicator used to indicate the unknown symbol 917 used in measurement 918 can be a fixed value or a value configured via higher-level signaling (e.g., RRC signaling), or implicitly determined based on the number of unknown symbols 917. For example, when the number of unknown symbols 917 is M, N = ceil(M / K) (K = 1).

[0211] If the number of unknown symbols 917 is 0, the base station may not transmit an indicator that indicates the unknown symbols used in measurement 918.

[0212] The terminal can obtain SFI information from the group common DCI transmitted by the base station. Based on the obtained SFI, the terminal can determine the time slot format of the corresponding time slot. The terminal can determine whether to perform measurement 918 in unknown symbol 917 according to the UE-specific DCI instruction transmitted by the base station, as indicated above. If the terminal receives an indicator indicating that measurement 918 should be performed in certain unknown symbols 917, the terminal can perform channel measurements (e.g., CSI measurements), power measurements (e.g., RSRP, RSRQ, RSSI measurements), or other measurements at the corresponding unknown symbol 917.

[0213] Example 3

[0214] In 5G, for various purposes (e.g., forward compatibility, PDSCH rate matching configuration indication, and PUSCH rate matching configuration indication), it is possible to configure certain time and frequency resources as reserved resources.

[0215] The base station can configure certain time / frequency resources as reserved resources to the terminal via higher-layer signaling (e.g., SI and RRC signaling). The time / frequency resources configured as reserved resources cannot be used for any communication between the base station and the terminal.

[0216] The base station configures certain symbols of a time slot as unknown symbols for the terminal via the SFI carried in the group common DCI. These unknown symbols may be overwritten by another DCI. If overwritten by another DCI, the unknown symbol can be used for the purpose indicated by the corresponding DCI. As described above in Embodiment 2, known symbols can be used for purposes such as downlink, uplink, gaps, and measurements. If an unknown symbol is not overwritten, it is assumed to be a reserved resource. That is, unknown symbols not overwritten by another DCI are not used for any communication between the base station and the terminal.

[0217] In the following description, reserved resources configured via higher-level signaling and unknown symbols indicated via group common DCI are collectively referred to as reserved resources.

[0218] Example 3 addresses the operation of the base station and terminal when a portion of the CORESET is configured as reserved resources, such as... Figure 10 As shown.

[0219] Figure 10 It is a diagram 1000 of CORESET 1001 including search space 1005, each of search space 1005 consisting of a set of CCE1006 (or a set of PDCCH candidates).

[0220] refer to Figure 10The time-frequency region including a portion of CORESET 1001 is configured as reserved resource 1002. CORESET 1001 may consist of an area overlapping with reserved resource 1002 (i.e., overlapping area 1003) and an area not overlapping with reserved resource 1002 (i.e., non-overlapping area 1004). The base station may map DCI to resources in non-overlapping area 1004, but not to resources in overlapping area 1003. This is because reserved resource 1002 cannot be used for any communication between the base station and the terminal. The terminal may receive DCI transmitted by the base station only in non-overlapping area 1004 of CORESET 1001.

[0221] The following section provides a description of the DCI transmission method of the base station and the control channel monitoring method of the terminal under the above conditions.

[0222] Example 3-1

[0223] When a portion of CORESET 1001 overlaps with reserved resource 1002, the base station can map the DCI to PDSCH candidates in the search space present in the non-overlapping region 1004. When the search space 1005 consists of eight CCEs 1006 (i.e., CCE 1007, CCE 1008, CCE 1009, CCE 1010, CCE 1011, CCE 1012, CCE 1013, and CCE 1014), five of these eight CCEs 1006 (i.e., CCE 1009, CCE 1010, CCE 1012, CCE 1013, and CCE 1014) are located in the non-overlapping region 1004, as follows... Figure 10 As shown, the base station can map DCI only to PDCCH candidates on CCE 1009, CCE1010, CCE 1012, CCE 1013 and CCE 1014.

[0224] In the case where a portion of CORESET 1001 overlaps with a reserved resource 1002, the terminal can perform blind decoding only in the search space present in the non-overlapping region 1004.

[0225] Example 3-2

[0226] If a portion of CORESET 1001 overlaps with reserved resource 1001, the base station may consider time-frequency resources (total number of REGs or CCEs) in the non-overlapping region 1004 to reconfigure the search space for the corresponding terminal and map the DCI to some PDCCH candidates in the reconfigured search space. The search space can be defined by the following equation (1).

[0227] Search space = f(Y) k , total number of CCEs, CCE index, AL, number of PDCCH candidates, carrier index)...(1)

[0228] In equation (1) above, f(x) represents a function with input x. Based on equation (1) above, the search space Y can be determined. k It represents any value that can be applied to the k-th time slot or subframe, and can have an initial value Y determined by the UE ID or a predetermined fixed value. -1 For example, Y can be determined based on the terminal ID of the terminal-specific search space or based on a value agreed upon by all UEs in a public search space. -1 .

[0229] According to equation (1) above, the search space can be expressed as a function of the total number of CCEs existing in the corresponding CORESET. Since CCEs are groups of REGs, each REG consists of 1 symbol in the time domain and 12 subcarriers in the frequency domain, the total number of CCEs is determined by configuring the entire time-frequency resources of the CORESET.

[0230] If CORESET 1001 partially overlaps with reserved resource 1002, the base station can recalculate the search space by replacing the total number of CCEs present in the non-overlapping area 1004 with the total number of CCEs present in the entire CORESET 1001. This can be expressed by the following equation (2).

[0231] Search space = f(Y) k (2) The total number of CCEs in the non-overlapping region, CCE index, AL, number of PDCCH candidates, carrier index)...

[0232] The base station can transmit the DCI to the corresponding terminal on a PDCCH candidate that exists in the search space recalculated by the above equation (2).

[0233] If CORESET 1001 partially overlaps with reserved resource 1002, the terminal may recalculate its search space by considering the time-frequency resources (total number of REGs or CCEs) in the non-overlapping region 1004 and perform blind decoding in the recalculated search space. The terminal may also recalculate the search space in the non-overlapping region 1004 of CORESET 1001 using the above equation (2).

[0234] Example 3-3

[0235] The base station can transmit DCI on a PDCCH candidate in CORESET 1001. If the time-frequency resources of the PDCCH candidate to be transmitted partially overlap with reserved resources 1002, the base station can perform rate matching to transmit the corresponding PDCCH. Figure 10 For example, a base station can transmit DCI on PDCCH candidates corresponding to CCEs 1007, 1008, 1009, and 1010. In this case, CCEs 1007 and 1008 are located in reserved resource 1002. Therefore, the base station can perform rate matching to transmit PDCCH using CCEs 1009 and 1010 located in non-overlapping area 1004 instead of CCEs 1007 and 1008 located in overlapping area 1003.

[0236] If CORESET 1001 partially overlaps with reserved resource 1002, the terminal can perform blind decoding in the search space based on the assumption that PDCCHs are transmitted after rate matching in the overlapping region 1003. For example, the terminal can perform blind decoding on the overlapping region 1003. For example, in the case of performing blind decoding on the PDCCHs corresponding to CCEs 1007, 1008, 1009, and 1010 in its search space, the terminal can perform blind decoding on the PDCCHs corresponding to CCEs 1009 and 1010, which are the remaining PDCCHs after rate matching of CCEs 1007 and 1008 located in the overlapping region 1003.

[0237] Examples 3-4

[0238] If CORESET 1001 partially overlaps with reserved resource 1002, the base station may not transmit any DCI to the UE in the corresponding CORESET 1001.

[0239] If CORESET 1001 partially overlaps with reserved resource 1002, the terminal may not monitor the corresponding CORESET 1001, i.e., may not perform blind decoding.

[0240] Example 4

[0241] In 5G communication systems, base stations can provide terminals with various configuration information (e.g., parameters listed in Table 3) regarding the CORESET used for transmitting downlink control channels via higher-layer signaling (e.g., RRC signaling). Example 4 pertains to a method for configuring the REG binding size as part of the CORESET configuration information.

[0242] In 5G communication systems, the REG binding size of the downlink control channel can vary depending on the symbol length of the CORESET. Table 6 below shows the relationship between the control area length and the REG binding size.

[0243] [Table 6]

[0244]

[0245] In Example 4, a method is provided to minimize signal overhead when the REG binding size varies depending on the CORESET symbol length.

[0246] The base station can configure the REG binding size to the terminal via higher-layer signaling (e.g., RRC signaling). The REG binding size can be selected from a set of parameter values ​​{X, Y}. The base station can select a value from the set of parameter values ​​and transmit the selected value to the terminal. For example, assuming the REG binding size parameter value set is {X, Y}, the base station can select one of X and Y, and notify the terminal of the selected value.

[0247] The terminal can receive configuration information indicating the REG binding size from the base station via higher-layer signaling (e.g., RRC signaling). The terminal can interpret the REG binding size value received from the base station based on the pre-configured CORESET symbol length.

[0248] Additionally, if the terminal receives the REG binding size value X from the base station, the terminal can perform the following operations based on the CORESET symbol length information.

[0249] Operation 1: If the length of the CORESET symbol configured for the terminal is A or B, the terminal can assume that the REG binding size is Z.

[0250] Operation 2: If the length of the CORESET symbol configured for the terminal is C, the terminal can assume that the REG binding size is X' (≠X).

[0251] If the base station configures the REG binding size to Y for the terminal, the terminal can apply the REG binding size Y as is.

[0252] In Example 4, it can be assumed that X = 2, X′ = 3, Y = 6, A = 1, B = 2 and C = 3.

[0253] Each terminal and base station consists of a transmitter, a receiver, and a processor, respectively, to implement the methods of the above embodiments, such as... Figure 11 and 12As shown. To support the downlink control and data channel transmission method of the base station and the downlink control and data channel reception method of the terminal as described in the above embodiments, the transmitter, receiver and processor of each of the base station and the terminal operate according to each embodiment.

[0254] Figure 11 This is a block diagram of terminal 1100 according to an embodiment.

[0255] refer to Figure 11 Terminal 1100 may include processor 1101, receiver 1102 and transmitter 1103.

[0256] Processor 1101 can control the overall operation of terminal 1100. For example, processor 1101 can control other components differently to complete the PDSCH mapping type configuration method, unknown symbol configuration method, CORESET monitoring method, and CORESET configuration method described in the above embodiments. Receiver 1102 and transmitter 1103 can be collectively referred to as transceivers. Transceivers can transmit signals to and receive signals from base stations. Signals may include control information and data. Transceivers may include: a radio frequency (RF) transmitter for up-conversion and amplification of the signals to be transmitted; and an RF receiver for low-noise amplification and down-conversion of the received signals. Transceivers can output signals received through a radio channel to processor 1101 and transmit signals output from processor 1101 through a radio channel.

[0257] Figure 12 This is a block diagram illustrating the configuration of a base station 1200 according to an embodiment.

[0258] refer to Figure 12 The base station 1200 may include a processor 1201, a receiver 1202, and a transmitter 1203.

[0259] Processor 1201 can control the overall operation of base station 1200. For example, processor 1201 can control other components to perform the PDSCH mapping type configuration method, unknown symbol configuration method, CORESET monitoring method, and CORESET configuration method described in the above embodiments. Receiver 1202 and transmitter 1203 can be collectively referred to as transceivers. Transceivers can transmit signals to and receive signals from terminals. Signals may include control information and data. Transceivers may include: an RF transmitter for up-conversion and amplification of the signals to be transmitted; and an RF receiver for low-noise amplification and down-conversion of the received signals. Transceivers can output signals received via a radio channel to processor 1201 and transmit signals output from processor 1201 via a radio channel.

[0260] As stated above, this disclosure is advantageous in the following respects: by employing effective initial cell access and paging methods, it facilitates the efficient provision of services with diverse needs in 5G wireless communication systems that support various parameter sets.

[0261] The embodiments and accompanying drawings disclosed herein aid in the explanation and understanding of this disclosure, but are not intended to limit its scope. It will be apparent to those skilled in the art that variations and modifications may be made thereto without departing from the scope of this disclosure as defined by the appended claims and their equivalents. Embodiments may be combined, in whole or in part, if desired.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, information indicating resources associated with a physical downlink shared channel (PDSCH) for which rate matching is to be performed, wherein the information is provided through a radio resource control (RRC) message and includes information for time resources and information for frequency resources; monitoring, in a search space associated with a control resource set (CORESET), first physical downlink control channel (PDCCH) candidates that do not overlap with the resources, wherein the resources are defined by a combination of time resources and frequency resources; and wherein second PDCCH candidates that overlap with the resources are not monitored; and identifying downlink control information (DCI) based on a result of monitoring the first PDCCH candidates, wherein the search space is defined by a set of PDCCH candidates for an aggregation level, each PDCCH candidate is defined by a set of control channel elements (CCEs) corresponding to an aggregation level, each CCE consists of six resource element groups (REGs), and each REG is one resource block (RB) across one orthogonal frequency division multiplexing (OFDM) symbol.

2. The method of claim 1, wherein, the search space includes resources to be monitored in the CORESET.

3. The method of claim 1, wherein, the first PDCCH candidates consist of a set of CCEs that do not overlap with the resources.

4. The method of claim 1, wherein, the second PDCCH candidates are mapped to one or more subcarriers that overlap with subcarriers of any RB of the resources in a slot, and wherein the resources are not available for the PDSCH. 5.A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a terminal, information indicating resources associated with a physical downlink shared channel (PDSCH) for which rate matching is to be performed, wherein the information is provided through a radio resource control (RRC) message and includes information for time resources and information for frequency resources; and transmitting, to the terminal, a downlink signal on first physical downlink control channel (PDCCH) candidates in a search space associated with a control resource set (CORESET) by excluding second PDCCH candidates that overlap with the resources, wherein the resources are defined by a combination of time resources and frequency resources, wherein the second PDCCH candidates that overlap with the resources are not monitored, and wherein the search space is defined by a set of PDCCH candidates for an aggregation level, each PDCCH candidate is defined by a set of control channel elements (CCEs) corresponding to an aggregation level, each CCE consists of six resource element groups (REGs), and each REG is one resource block (RB) across one orthogonal frequency division multiplexing (OFDM) symbol.

6. The method of claim 5, wherein, the search space includes resources to be monitored in the CORESET, and wherein the first PDCCH candidates consist of a set of CCEs that do not overlap with the resources.

7. The method of claim 5, wherein, the second PDCCH candidates are mapped to one or more subcarriers that overlap with subcarriers of any RB of the resources in a slot, and wherein the resources are not available for the PDSCH. 8.A terminal in a wireless communication system, the terminal comprising: at least one transceiver; and at least one processor communicatively coupled to the at least one transceiver; and at least one memory communicatively coupled to the at least one processor storing instructions executable by the at least one processor, alone or in any combination, to cause the terminal to: receive, from a base station, information indicating resources associated with a physical downlink shared channel (PDSCH) to be rate matched, wherein the information is provided through a radio resource control (RRC) message and includes information for time resources and information for frequency resources, monitor, in a search space associated with a control resource set (CORESET), first physical downlink control channel (PDCCH) candidates that do not overlap with the resources, wherein the resources are defined by a combination of time resources and frequency resources, and wherein second PDCCH candidates that overlap with the resources are not monitored, and identify downlink control information (DCI) based on a result of monitoring the first PDCCH candidates, wherein the search space is defined by a set of PDCCH candidates for an aggregation level, each PDCCH candidate is defined by a set of control channel elements (CCEs) corresponding to the aggregation level, each CCE consists of six resource element groups (REGs), and each REG is one resource block (RB) across one orthogonal frequency-division multiplexing (OFDM) symbol.

9. The terminal according to claim 8, wherein the search space includes resources to be monitored in the CORESET.

10. The terminal of claim 8, wherein, the first PDCCH candidates consist of a set of CCEs that do not overlap with the resources.

11. The terminal of claim 8, wherein, the second PDCCH candidates are mapped to one or more subcarriers in a slot that overlap with subcarriers of any RB of the resources, and wherein the resources are not available for the PDSCH.

12. A base station in a wireless communication system, the base station comprising: at least one transceiver; and at least one processor communicatively coupled to the at least one transceiver; and at least one memory communicatively coupled to the at least one processor storing instructions executable by the at least one processor, alone or in any combination, to cause the base station to: transmit, to a terminal, information indicating resources associated with a physical downlink shared channel (PDSCH) to be rate matched, wherein the information is provided through a radio resource control (RRC) message and includes information for time resources and information for frequency resources, and transmit, to the terminal, a downlink signal on first physical downlink control channel (PDCCH) candidates in a search space associated with a control resource set (CORESET) by excluding second PDCCH candidates that overlap with the resources, wherein the resources are defined by a combination of time resources and frequency resources, wherein the second PDCCH candidates that overlap with the resources are not monitored, and wherein the search space is defined by a set of PDCCH candidates for an aggregation level, each PDCCH candidate is defined by a set of control channel elements (CCEs) corresponding to the aggregation level, each CCE consists of six resource element groups (REGs), and each REG is one resource block (RB) across one orthogonal frequency-division multiplexing (OFDM) symbol.

13. The base station of claim 12, wherein, The search space includes resources in a CORESET to be monitored.

14. The base station of claim 12, wherein, The first PDCCH candidate consists of a set of CCEs that do not overlap with the resources.

15. The base station of claim 12, wherein, The second PDCCH candidate is mapped to one or more subcarriers in a slot that overlap with subcarriers of any RB of the resources, and wherein the resources are not available for PDSCH.

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