Apparatus and method for inter-cell interference control for wireless communication system

Abstract

The disclosure relates to a 5G communication system and an Internet of Things (IoT) technology communication technique supporting higher data rates after convergence of 4G systems and a system thereof. Based on the 5G communication techniques and IoT-related techniques, the disclosure can be applied to intelligent services (e.g., smart home, smart building, smart city, smart or connected car, health care, digital education, retail, security and safety-related services, etc.). In addition, the disclosure relates to a method and an apparatus for performing communication in a wireless communication system including a plurality of cells.

Description

Technical Field

[0001] This disclosure generally relates to methods and apparatus for performing communications in a wireless communication system comprising multiple cells. Background Technology

[0002] To meet the increased demand for wireless data services since the deployment of fourth-generation (4G) communication systems, efforts have been made to develop improved fifth-generation (5G) or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "beyond 4G networks" or "post-LTE" systems. 5G communication systems are considered to be implemented in higher frequency (millimeter-wave (mmWave)) bands (e.g., the 60 GHz band) 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 have been discussed in 5G communication systems.

[0003] 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, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM), sliding window superposition coding (SWSC) are being developed as advanced coding and modulation (ACM), while filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) are being developed 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), combining IoT technology with big data processing technology, has emerged through connectivity with cloud servers. Because IoT implementation requires technological elements such as sensing technology, wireless communication and network infrastructure, wired 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 human life by collecting and analyzing data generated between interconnected things. Through the convergence and integration of existing information technology (IT) and 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] 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. Cloud radio access networks (RAN), as an application of the aforementioned big data processing technologies, can also be considered an example of the integration of 5G and IoT technologies.

[0006] For coexistence between LTE and New Radio (LTE-NR coexistence), NR provides NR User Equipment (UE) with the ability to configure cell-specific reference signal (CRS) modes for LTE. In a UE configured with a single Transmit and Receive Point (TRP), only one CRS mode can be configured per LTE carrier. Therefore, if in a multi-cell environment, multiple neighboring LTE cells use different CRS modes than the UE's serving cell (LTE-NR coexistence cell), the UE may experience considerable interference from these neighboring LTE cells. This problem can be mitigated through appropriate scheduling at the base station, but there are limitations: scheduling can be performed per resource block (RB), and CRS can be mapped per resource element (RE). Summary of the Invention

[0007] Technical issues

[0008] One aspect of this disclosure is to provide a method and apparatus for efficiently providing services.

[0009] Problem Solution

[0010] The present invention aims to solve the above-mentioned problems and disadvantages, and provides at least the following advantages.

[0011] According to one aspect of this disclosure, a method performed by a terminal in a communication system is provided. The method includes receiving configuration information associated with a CRS mode of a cell from a base station via higher-layer signaling; determining the RE of the CRS based on the configuration information; determining whether the Physical Downlink Shared Channel (PDSCH) is received on the RE of the CRS; and receiving the PDSCH from the base station based on the determination, wherein if the PDSCH is received on the RE of the CRS, interference cancellation is performed to receive the PDSCH.

[0012] According to another aspect of this disclosure, a terminal in a communication system is provided. The terminal includes a transceiver; and a controller configured to: receive configuration information associated with a cell's CRS mode from a base station via higher-layer signaling; determine the RE of the CRS based on the configuration information; determine whether a PDSCH is received on the RE of the CRS; and receive the PDSCH from the base station based on the determination, wherein if the PDSCH is received on the RE of the CRS, the PDSCH is received by performing interference cancellation.

[0013] According to another aspect of this disclosure, a method performed by a base station in a communication system is provided. The method includes transmitting configuration information associated with a cell's CRS mode to a terminal via higher-layer signaling; determining the RE of the CRS based on the configuration information; determining whether to transmit a PDSCH on the RE of the CRS; and transmitting the PDSCH to the terminal based on the determination.

[0014] According to another aspect of this disclosure, a base station in a communication system is provided. The base station includes a transceiver; and a controller configured to: transmit configuration information associated with a cell's CRS mode to a terminal via higher-layer signaling; determine the RE of the CRS based on the configuration information; determine whether to transmit a PDSCH on the RE of the CRS; and transmit the PDSCH to the terminal based on the determination.

[0015] Beneficial effects of the invention

[0016] According to the disclosed embodiments, services can be effectively provided in wireless communication systems where NR and LTE networks coexist. Attached Figure Description

[0017] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 This is a diagram illustrating the basic structure of the time-frequency domain according to an embodiment, wherein the time-frequency domain is the radio resource domain for transmitting data or control channels in a 5G system;

[0019] Figure 2 This is a diagram illustrating an example of a time slot structure considered in a 5G system according to an embodiment;

[0020] Figure 3 This is a diagram illustrating an example of configuring a bandwidth portion (BWP) in a 5G communication system according to an embodiment;

[0021] Figure 4 This is a diagram illustrating an example of a control resource set (CORESET) according to an embodiment, through which a downlink control channel is transmitted in a 5G wireless communication system;

[0022] Figure 5 This is a diagram illustrating an example of the basic units of time and frequency resources of a downlink control channel that can be used in 5G according to an embodiment;

[0023] Figure 6 This is a diagram illustrating a method by which a base station and a UE, according to an embodiment, transmit and receive data, taking into account downlink data channel and rate matching resources.

[0024] Figure 7A This is a diagram illustrating an example of the operation of a base station in a wireless communication system according to an embodiment;

[0025] Figure 7B This is a diagram illustrating an example of the operation of a UE in a wireless communication system according to an embodiment;

[0026] Figure 8 This is a diagram illustrating an example of the operation of a UE in a wireless communication system according to an embodiment;

[0027] Figure 9A This is a diagram illustrating an example of the operation of a base station in a wireless communication system according to an embodiment;

[0028] Figure 9B This is a diagram illustrating an example of the operation of a UE in a wireless communication system according to an embodiment;

[0029] Figure 10A This is a diagram illustrating an example of the operation of a UE in a wireless communication system according to an embodiment;

[0030] Figure 10B This is a diagram illustrating an example of the operation of a UE in a wireless communication system according to an embodiment;

[0031] Figure 11 This is a diagram illustrating an example of the operation of a UE in a wireless communication system according to an embodiment;

[0032] Figure 12 This is a block diagram of the UE according to an embodiment; and

[0033] Figure 13 This is a block diagram of a base station according to an embodiment. Detailed Implementation

[0034] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0035] According to the disclosed embodiments, services can be effectively provided in wireless communication systems where NR and LTE networks coexist.

[0036] In describing embodiments of this disclosure, descriptions related to techniques known in the art and not directly related to this disclosure will be omitted. Unnecessary descriptions are omitted to prevent obscuring the main ideas of this disclosure and to more clearly convey them.

[0037] For the same reason, some elements may be exaggerated, omitted, or shown schematically in the accompanying drawings. Furthermore, the size of each element does not perfectly reflect its actual size. In the drawings, identical or corresponding elements have the same reference numerals.

[0038] The advantages and features of this disclosure, and the ways in which they are implemented, will become apparent from the embodiments described in detail below with reference to the accompanying drawings. However, this disclosure is not limited to the embodiments set forth below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose this disclosure and to inform those skilled in the art of its scope, and this disclosure is limited only by the scope of the appended claims. Throughout the specification, the same or similar reference numerals denote the same or similar elements. Furthermore, in describing this disclosure, detailed descriptions of known functions or configurations incorporated herein are omitted where it is determined that such description might unnecessarily obscure the subject matter of the disclosure. The terminology described below is defined in consideration of the functions in this disclosure and may vary depending on the user, the user's intention, or custom. Therefore, the definition of the terminology should be based on the entire contents of the specification.

[0039] In the following description, a base station is an entity that allocates resources to a terminal and can be at least one of a gNode B, eNode B, Node B, BS, radio access unit, base station controller, and a node on a network. A terminal can include a UE, mobile station (MS), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. In this disclosure, "downlink" refers to the radio link through which a base station transmits signals to a terminal, and "uplink" refers to the radio link through which a terminal transmits signals to a base station. Furthermore, although the following description is by way of example directed to LTE or LTE-A Advanced (LTE-A) systems, embodiments of this disclosure can also be applied to other communication systems with similar technical backgrounds or channel types to embodiments of this disclosure. Examples of other communication systems may include 5G mobile communication technology (5G NR) developed in addition to LTE-A, and in the following description, "5G" can be a concept covering existing LTE, LTE-A, and other similar services. Moreover, based on the determination of those skilled in the art, this disclosure can be applied to other communication systems with some modifications without explicitly departing from the scope of this disclosure.

[0040] Here it will be understood that each box shown in the flowchart, and combinations of boxes shown in the flowchart, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to generate a machine such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more boxes of the flowchart. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium that can instruct the computer or other programmable data processing apparatus to operate in a particular manner such that the instructions stored in the computer-usable or computer-readable storage medium generate an article of manufacture including instruction means for implementing the functions specified in the flowchart blocks or blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus, thereby generating a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more boxes of the flowchart.

[0041] Furthermore, each box in the flowchart can represent a module, code segment, or code section, which includes one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions mentioned in the boxes may not appear in a specific order. For example, two boxes shown consecutively may actually be executed substantially simultaneously, or these boxes may sometimes be executed in reverse order, depending on the functions involved.

[0042] As used herein, "unit" refers to a software or hardware element that performs a predetermined function, such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). However, "unit" does not always have a meaning limited to software or hardware. A "unit" can be configured to be stored in addressable memory or to execute one or more processors. Therefore, a "unit" includes, for example, software elements, object-oriented software elements, class or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and parameters. The elements and functions provided by a "unit" can be combined into a smaller number of elements or divided into a larger number of elements. Furthermore, elements and "units" can be implemented as one or more central processing units (CPUs) replicated within a device or secure multimedia card. Additionally, a "unit" may include one or more processors.

[0043] Wireless communication systems have evolved from providing initial voice-oriented services to broadband wireless communication systems that provide high-speed and high-quality packet data services, such as High-Speed ​​Packet Access (HSPA) in the 3rd Generation Partnership Project (3GPP), LTE or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-A, LTE-pro, High-Speed ​​Packet Data (HRPD) in 3GPP2, Ultra Mobile Broadband (UMB), and communication standards such as the Institute of Electrical and Electronics Engineers (IEEE) 802.16e.

[0044] In LTE systems, a representative example of broadband wireless communication systems, Orthogonal Frequency Division Multiplexing (OFDM) is used in the downlink, and Single-Carrier Frequency Division Multiple Access (SC-FDMA) is used in the uplink. The uplink refers to the radio link through which the UE (or MS) transmits data or control signals to the base station (or eNode B), and the downlink refers to the radio link through which the base station transmits data or control signals to the UE. These multiple access methods allow for the differentiation of each user's data or control information to avoid overlap by allocating and manipulating the time-frequency resources to which each user's data or control information will be transmitted, thereby establishing orthogonality.

[0045] As the communication system following LTE, 5G communication systems must support services that simultaneously meet diverse needs, thus freely reflecting various demands from users and service providers. Services considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC).

[0046] eMBB aims to provide higher data transmission rates than those supported by existing LTE, LTE-A, or LTE-Pro systems. For example, in a 5G communication system, from a base station's perspective, eMBB should be able to provide a peak data rate of 20 gigabits per second (Gbps) in the downlink and 10 Gbps in the uplink. Furthermore, 5G communication systems must simultaneously provide both the UE's peak data rate and increased user-aware data rates. To meet these requirements, various improved transmit / receive technologies are needed, including more advanced multi-antenna (multiple-input multiple-output (MIMO)) transmission technologies. Moreover, while LTE systems use a transmission bandwidth of up to 20 MHz in the 2 GHz band to transmit signals, 5G communication systems can meet their required data transmission rates by using a wider frequency bandwidth than 20 MHz in the 3 to 6 GHz or higher bands.

[0047] Meanwhile, mMTC is considering supporting application services such as IoT in 5G communication systems. To effectively deliver IoT, mMTC needs to support large-scale UE access within the cell, improve UE coverage, increase battery life, and reduce UE costs. Because IoT is attached to various sensors and devices to provide communication functions, it must be able to support many UEs within the cell (e.g., 1,000,000 UEs / km²). 2 Furthermore, because mMTC-enabled UEs are likely to be located in shadow areas not covered by the cell, such as building basements, they may require wider coverage compared to other services offered by 5G communication systems due to the nature of the service. mMTC-enabled UEs must be low-cost UEs, and because it is difficult to frequently replace UE batteries, they may require very long battery life, such as 10 to 15 years.

[0048] Finally, URLLC is a cellular-based wireless communication service used for specific purposes (mission-critical). For example, services for remote control of robots or machines, industrial automation, unmanned aerial vehicles, remote healthcare, or emergency alerts could be considered. Therefore, the communication provided by URLLC must offer very low latency and very high reliability. For example, services supporting URLLC must meet an air interface latency of less than 0.5 milliseconds (ms) while also meeting 10... -5 Or a lower packet error rate requirement. Therefore, for services supporting URLLC, 5G communication systems must provide smaller transmission time intervals (TTIs) than other services, while allocating wide resources in the frequency band to ensure the reliability of the communication link.

[0049] The three services of a 5G communication system—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. In this case, different transmit / receive technologies and parameters can be used between services to meet the different requirements of each service. 5G is not limited to these three services.

[0050] The frame structure of a 5G system will be described in more detail below with reference to the accompanying drawings.

[0051] Figure 1 This is a diagram illustrating the basic structure of the time-frequency domain according to an embodiment, wherein the time-frequency domain is the radio resource domain for transmitting data or control information in a 5G communication system.

[0052] refer to Figure 1The horizontal and vertical axes represent the time and frequency domains, respectively. The basic unit of a resource in both the time and frequency domains is an RE 101, which can be defined as an OFDM symbol 102 on the time axis and as a subcarrier 103 on the frequency axis. In the frequency domain, (For example, 12 consecutive REs can be configured into an RB 104.)

[0053] Figure 2 This is a diagram illustrating the time slot structure considered in a 5G communication system according to an embodiment.

[0054] Figure 2 An example of the structure of frame 200, subframe 201, and time slot 202 is shown.

[0055] refer to Figure 2 A frame 200 can be defined as 10 ms. A subframe 201 can be defined as 1 ms. In this case, a frame 200 can consist of a total of 10 subframes 201. Time slots 202 and 203 can be defined as 14 OFDM symbols (i.e., the number of symbols per time slot). =14). A subframe 201 may include one or more time slots 202 and 203, and the number of time slots 202 and 203 in each subframe 201 may vary depending on the subcarrier spacing setting value μ, where μ = 0 at reference numeral 204 and μ = 1 at reference numeral 205. When μ = 0 at 204, a subframe 201 may include one time slot 202, and when μ = 1 at 205, a subframe 201 may include two time slots 203. That is, the number of time slots in each subframe depends on the subcarrier spacing setting value μ. It can change, and accordingly, the number of time slots per frame. It can be changed. The value μ is set according to the interval of each subcarrier. and It can be defined in Table 1 below.

[0056] [Table 1]

[0057]

[0058] Next, we will refer to Figure 3 Provide a detailed description of the BWP configuration in a 5G communication system.

[0059] Figure 3 This is a diagram illustrating an example of a BWP configuration for a 5G communication system according to an embodiment.

[0060] Figure 3An example is shown where UE bandwidth 300 is configured as two BWPs, namely BWP#1 301 and BWP#2 302. The base station can configure one or more BWPs for the UE, and can configure the information shown in Table 2 below for each BWP.

[0061] [Table 2]

[0062]

[0063]

[0064] Beyond the examples above, various parameters related to the BWP can be configured in the UE in addition to the configuration information described above. This information can be sent to the UE by the base station via higher-layer signaling (e.g., Radio Resource Control (RRC) signaling). At least one of one or more configured BWPs can be activated. Whether a configured BWP is activated can be semi-statically sent from the base station to the UE via RRC signaling, or dynamically sent via downlink control information (DCI). Before RRC connection, the UE can receive the initial BWP configuration for initial connection from the base station via the Master Information Block (MIB). More specifically, during the initial access step, the UE can receive configuration information for the CORESET, through which the Physical Downlink Control Channel (PDCCH) can be sent for receiving system information required for initial access (e.g., Residual System Information (RMSI) or System Information Block (SIB) 1). The UE can also receive the search space via the MIB. The CORESET and search space configured by the MIB can be considered as ID 0. The base station can notify the UE of configuration information, such as frequency allocation information, time allocation information, and parameter set for CORESET#0, via the MIB. Furthermore, the base station can notify the UE of configuration information regarding the monitoring period and timing of CORESET#0 via the MIB, i.e., configuration information regarding search space #0. The UE can consider the frequency domain configured as CORESET#0 obtained from the MIB as the initial BWP for initial access. In this case, the ID of the initial BWP can be considered as 0.

[0065] 5G-supported BWP configurations can be used for a variety of purposes.

[0066] When the bandwidth supported by the UE is less than the system bandwidth, the UE can be supported through BWP configuration. For example, the base station can configure the frequency position of the BWP for the UE (configuration information 2), so that the UE can send and receive data at a specific frequency position within the system bandwidth.

[0067] Furthermore, to support different parameter sets, the base station can configure multiple BWPs for the UE. For example, to support sending and receiving data to any UE using subcarrier spacing of 15 kHz and 30 kHz, two BWPs can be configured with subcarrier spacings of 15 kHz and 30 kHz, respectively. Different BWPs can be frequency-division multiplexed (FDM), and the BWP configured for the corresponding subcarrier spacing can be activated when sending / receiving data using a specific subcarrier spacing.

[0068] Furthermore, to reduce UE power consumption, the base station can configure the UE with a BWP of different bandwidths. For example, when the UE supports a very large bandwidth (e.g., 100MHz) and always uses the corresponding bandwidth to send and receive data, it may consume a lot of power. In particular, monitoring the downlink control channel on an unnecessarily large bandwidth of 100MHz is very inefficient in terms of power consumption for the UE when there is no service. To reduce UE power consumption, the base station can configure the UE with a relatively small BWP, such as a 20MHz BWP. When there is no service, the UE can monitor in a 20MHz BWP, and when data is generated, the UE can use a 100MHz BWP to send / receive data according to the base station's instructions.

[0069] In the method of configuring the BWP, the UE can receive the configuration information of the initial BWP via the MIB during the initial access step before RRC connection. More specifically, the UE can receive the configuration of the CORESET for the downlink control channel from the MIB of the physical broadcast channel (PBCH), through which the DCI for scheduling SIBs can be transmitted. The bandwidth of the CORESET configured via the MIB can be regarded as the initial BWP, and with the configured initial BWP, the UE can receive the PDSCH through which SIBs are transmitted. In addition to the purpose of receiving SIBs, the initial BWP can be used for other System Information (OSI), paging, and random access.

[0070] Next, the synchronization signal (SS) / PBCH block in 5G will be described.

[0071] An SS / PBCH block can refer to a physical layer channel block composed of a primary SS (PSS), a secondary SS (SSS), and a PBCH. Specifically, PSS, SSS, PBCH, and SS / PBCH can be defined as follows:

[0072] -PSS: Used as a reference for downlink time / frequency synchronization and provides some information about the cell ID.

[0073] -SSS: Used as a reference for downlink time / frequency synchronization and provides remaining cell ID information not provided by PSS. Additionally, SSS can be used as a reference signal for demodulating PBCH.

[0074] -PBCH: Provides basic system information required for transmitting and receiving data and control channels for the UE. Basic system information may include search space-related control information indicating radio resource mapping information for control channels, and scheduling control information regarding separate data channels used for transmitting system information.

[0075] -SS / PBCH Blocks: SS / PBCH blocks consist of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be sent within 5ms, and each sent SS / PBCH block can be distinguished by an index.

[0076] The UE can detect the PSS and SSS during the initial access phase and can decode the PBCH. The UE can obtain the MIB from the PBCH and receive the CORESET#0 configured therefrom (which may correspond to a CORESET with CORESET index 0). The UE can monitor CORESET#0, assuming the selected SS / PBCH block and the demodulation reference signal (DMRS) transmitted from CORESET#0 are quasi-co-located (QCL). The UE can receive system information transmitted from CORESET#0 as DCI. The UE can obtain the Random Access Channel (RACH) configuration information required for initial access from the received system information. Considering the selected SS / PBCH index, the UE can transmit a Physical RACH (PRACH) to the base station, and the base station receiving the PRACH can obtain information about the SS / PBCH block index selected by the UE. The base station can check which block the UE selects from each SS / PBCH block and can recognize the fact that CORESET#0 associated with the selected block is being monitored.

[0077] Next, we will describe DCI in a 5G communication system in detail.

[0078] In 5G communication systems, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or PDSCH) can be transmitted from the base station to the UE via DCI. For PUSCH or PDSCH, the UE can monitor the DCI format used for backoff and the DCI format used for non-backoff. The DCI format used for backoff may include predefined fixed fields between the base station and the UE, while the DCI format used for non-backoff may include configurable fields.

[0079] Following the channel coding and modulation process, the DCI can be transmitted via the PDCCH. Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled with a Radio Network Temporary ID (RNTI) corresponding to the UE's identifier. Different RNTIs are used depending on the purpose of the DCI message (e.g., UE-specific data transmission, power control command, or random access response). That is, the RNTI is not explicitly transmitted but is included in and transmitted during the CRC calculation process. When a DCI message is received via the PDCCH, the UE uses the assigned RNTI to identify the CRC, and if the CRC identification result is correct, the UE recognizes that the message has been sent.

[0080] For example, the DCI for scheduling PDSCH used for System Information (SI) can be scrambled using SI-RNTI. The DCI for scheduling PDSCH used for Random Access Response (RAR) messages can be scrambled using RA-RNTI. The DCI for scheduling PDSCH used for paging messages can be scrambled using P-RNTI. The DCI for notifying Slot Format Indicator (SFI) can be scrambled using SFI-RNTI. The DCI for notifying Transmit Power Control (TPC) can be scrambled using TPC-RNTI. The DCI for scheduling UE-specific PDSCH or PUSCH can be scrambled using Cell-RNTI (C-RNTI).

[0081] DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, and in this case, CRC can be scrambled with C-RNTI. The DCI format 0_0 with CRC scrambled with C-RNTI can include information such as that shown in Table 3 below.

[0082] [Table 3]

[0083]

[0084]

[0085] DCI format 0_1 ​​can be used as a non-back-off DCI for scheduling PUSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with CRC scrambled with C-RNTI can include information such as that shown in Table 4 below.

[0086] [Table 4]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 1_0 with CRC scrambled with C-RNTI can include information such as that shown in Table 5 below.

[0095] [Table 5]

[0096]

[0097]

[0098] DCI format 1_1 can be used as a non-back-off DCI for scheduling PDSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 1_1 with CRC scrambled with C-RNTI can include information such as that shown in Table 6 below.

[0099] [Table 6]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] The following section describes a method for allocating time-domain resources for data channels in a 5G communication system.

[0106] The base station can configure tables for the UE to allocate time-domain resources for downlink data channels (e.g., PDSCH) and uplink data channels (e.g., PUSCH) via higher-layer signaling (e.g., RRC signaling). The base station can configure a table for PDSCH consisting of a maximum of 16 entries (maxNrofDL-Allocations = 16) and for PUSCH consisting of a maximum of 16 entries (maxNrofDL-Allocations = 16). The time-domain resource allocation information may include, for example, PDCCH-PDSCH time slot timing (corresponding to the time interval in time slots between the time of receiving the PDCCH and the time of sending the PDSCH scheduled by the received PDCCH, denoted by K0) or PDCCH-PUSCH time slot timing (corresponding to the time interval in time slots between the time of receiving the PDCCH and the time of sending the PUSCH scheduled by the received PDCCH, denoted by K2), information regarding the position and length of the starting symbol for scheduling the PDSCH or PUSCH in the time slot, and the mapping type of the PDSCH or PUSCH. For example, the information shown in Table 7 below can be notified from the base station to the UE, and the information shown in Table 8 below can be notified from the UE to the base station.

[0107] [Table 7]

[0108]

[0109] [Table 8]

[0110]

[0111] The base station can notify the UE of one of the entries in the table of time-domain resource allocation information via L1 signaling (e.g., DCI). (For example, the base station uses the "Time-domain Resource Allocation" field in the DCI to indicate this.) The UE can obtain the time-domain resource allocation information of PDSCH or PUSCH based on the DCI received from the base station.

[0112] The following section describes a method for allocating frequency domain resources for data channels in a 5G communication system.

[0113] In 5G, resource allocation type 0 and resource allocation type 1 are supported as methods to indicate frequency domain resource allocation information for downlink data channels (e.g., PDSCH) and uplink data channels (e.g., PUSCH).

[0114] Resource allocation type 0

[0115] RB allocation information can be communicated to the UE from the base station in the form of a bitmap of RB groups (RBGs). In this case, an RBG can consist of a set of consecutive VRBs, and the size P of the RBG can be determined based on the value configured by the higher-layer parameter (rbg-Size) and the size value of the BWP defined in Table 9 below.

[0116] [Table 9]

[0117] BWP size Configuration 1 Configuration 2 1-36 2 4 37-72 4 8 73-144 8 16 145-275 16 16

[0118] Nominal RBG size P

[0119] Size is The total number of RBGs of BWP i (N) RBG It can be defined based on equation (1) as follows:

[0120]

[0121] The size of the first RBG is if The size of the last RBG is Otherwise, the value is P, and the size of all other RBGs is P.

[0122] N RBG Each bit of a bitmap of size bit can correspond to a RBG. RBGs can be indexed starting from the lowest frequency position of the BWP and proceeding in ascending frequency order. For N in the BWP... RBG RBG, RBG#0 to RBG#(N) RBG -1) The RBG bitmap can be mapped from the most significant bit (MSB) to the least significant bit (LSB). When a specific bit in the bitmap is 1, the UE can determine that an RBG corresponding to that bit value has been allocated, and when a specific bit in the bitmap is 0, the UE can determine that an RBG corresponding to that bit value has not been allocated.

[0123] Resource allocation type 1

[0124] RB allocation information can be communicated from the base station to the UE as information about the start position and length of consecutively allocated VRBs. In this case, interleaving or non-interleaving can be additionally applied to the consecutively allocated VRBs. The resource allocation field of resource allocation type 1 can consist of a resource indication value (RIV), which can be determined by the start point of the VRB (RB). start ) and the length of the continuously allocated RB (L) RBs Composed of ) More specifically, the size is The RIV of a BWP can be defined as follows:

[0125] if but

[0126]

[0127] otherwise

[0128]

[0129] Among them, L RBs ≥1 and will not exceed

[0130] The downlink control channel in a 5G communication system will be described in more detail below with reference to the accompanying drawings.

[0131] Figure 4 This is a diagram illustrating an example of CORESET according to an embodiment, wherein a downlink control channel is transmitted in a 5G wireless communication system.

[0132] refer to Figure 4 The UE BWP 410 is configured on the frequency axis, and two control sets, CORESET#1 401 and CORESET#2 402, are configured in a time slot 420 on the time axis. CORESETs 401 and 402 can be configured to specific frequency resources 403 within the entire UE BWP 410 in the frequency domain. One or more OFDM symbols can be configured in the time domain, and this can be defined as the CORESET duration 404. (Reference) Figure 4 As shown in the example, CORESET#1 401 can be configured to a CORESET length of 2 symbols, and CORESET#2 402 can be configured to a CORESET length of 1 symbol.

[0133] In 5G, the CORESET mentioned above can be configured by the base station to the UE via higher-level signaling (e.g., system information, MIB, or RRC signaling). Configuring a CORESET for a UE involves providing information such as the CORESET ID, the frequency location of the CORESET, and the symbol length of the CORESET. For example, Table 10 below shows the information provided for configuring a CORESET.

[0134] [Table 10]

[0135]

[0136]

[0137] In Table 10, the tci-StatesPDCCH (Transmission Configuration Indicator (TCI) status) configuration information may include information about the QCL relationship between one or more SS / PBCH block indices and the DMRS transmitted in the corresponding CORESET or CSI-RS index.

[0138] Figure 5 This is a diagram illustrating an example of the basic unit of time and frequency resources of a downlink control channel that can be used in 5G according to an embodiment.

[0139] refer to Figure 5 The basic unit constituting the time and frequency resources of the control channel can be called a resource element group (REG) 503, and REG 503 can be defined as one OFDM symbol 501 on the time axis and one physical resource block (PRB) 502 on the frequency axis, i.e., 12 subcarriers. The base station can configure the downlink control channel allocation unit by cascading REG 503.

[0140] like Figure 5 As shown, in a 5G communication system, the basic unit to which the downlink control channel is allocated is called a Control Channel Element (CCE) 504, and one CCE 504 can be composed of multiple REG 503s. (Description) Figure 5 As shown in the diagram, REG 503 can consist of 12 REs, and if one CCE 504 consists of 6 REG 503s, then one CCE 504 can consist of 72 REs. When configuring a downlink CORESET, the corresponding area can consist of multiple CCE 504s, and a specific downlink control channel is mapped to one or more CCE 504s and transmitted according to the aggregation level (AL) in the control area. Multiple CCE 504s in a CORESET can be allocated according to a logical mapping method.

[0141] The basic unit of the downlink control channel (i.e., Figure 5 The REG 503 shown may include the RE mapped to by the DCI and the region mapped to by the DMRS as the RS used for decoding the RE. Figure 5As shown, three DMRS 505s can be transmitted within a single REG 503. Depending on AL, the number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16, and different numbers of CCEs can be used to achieve link adaptation of the downlink control channel. For example, when AL = L, a downlink control channel can be transmitted with L CCEs. The UE may need to detect signals without considering information on the downlink control channel, and for blind decoding, a search space indicating the set of CCEs can be defined. Because the search space can be a set of downlink control channel candidates that includes the CCEs the UE should attempt to decode at a given aggregation level, and several aggregation levels can form a bundle with 1, 2, 4, 8, or 16 CCEs, the UE can have multiple search spaces. The search space set can be defined as the set of search spaces across all configured aggregation levels.

[0142] The search space can be categorized into a common search space and a UE-specific search space. A group of UEs or all UEs can check the common search space of the PDCCH to receive dynamic scheduling of cell common control information, such as system information or paging messages. By checking the common search space of the PDCCH, a UE can receive PDSCH scheduling allocation information for transmitting SIBs, including cell operator information. In the case of the common search space, since a group of UEs or all UEs must receive the PDCCH, the common search space can be defined as the set of committed CCEs. UE-specific PDSCH or PUSCH scheduling allocation information can be received by checking the UE-specific search space of the PDCCH. The UE-specific search space can be UE-specifically defined as a function of the UE's identifier and various system parameters.

[0143] In 5G, parameters for the search space used for PDCCH can be configured from the base station to the UE via higher-layer signaling (e.g., SIB, MIB, and RRC signaling). The base station can configure for the UE the number of PDCCH candidates at each aggregation level L, the monitoring period of the search space, the monitoring timing of the search space in symbols within a time slot, the search space type (common search space or UE-specific search space), the combination of DCI format and RNTI to be monitored in the corresponding search space, or the CORESET index for monitoring the UE's search space. Parameters for the search space used for PDCCH can include the information shown in Table 11 below.

[0144] [Table 11]

[0145]

[0146]

[0147] According to the configuration information, the base station can configure one or more search space sets for the UE. The base station can configure search space set 1 and search space set 2 for the UE. In search space set 1, the UE can be configured to monitor DCI format A scrambled with X-RNTI in a common search space, and in search space set 2, the UE can be configured to monitor DCI format B scrambled with Y-RNTI in a UE-specific search space. According to the configuration information, one or more search space sets can exist in either a common search space or a UE-specific search space. For example, search space set #1 and search space set #2 can be configured as a common search space, and search space set #3 and search space set #4 can be configured as UE-specific search spaces.

[0148] In the public search space, combinations of the following DCI formats and RNTI can be monitored. This is not limited to the examples below.

[0149] -DCI format 0_0 / 1_0, with CRC scrambled by C-RNTI, Configuration and Scheduling (CS)-RNTI, SP-CSI-RNTI, Random Access (RA)-RNTI, Temporary Cell (TC)-RNTI, Paging (P)-RNTI, and System Information (SI)-RNTI.

[0150] -DCI format 2_0, with CRC scrambled by SFI-RNTI

[0151] -DCI format 2_1, with CRC scrambled by interrupt (INT)-RNTI.

[0152] -DCI format 2_2, with CRC scrambled by TPC-PUSCH-RNTI and TPC-PUCCH-RNTI.

[0153] -DCI format 2_3, with CRC scrambled by RNTI TPC-SRS

[0154] Within the UE-specific search space, combinations of the following DCI formats and RNTI can be monitored. This is not limited to the examples below.

[0155] -DCI format 0_0 / 1_0, with CRC scrambled by C-RNTI, CS-RNTI, and TC-RNTI.

[0156] -DCI format 1_0 / 1_1, with RNTI specified by CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI, can follow the following definitions and uses.

[0157] C-RNTI: UE-specific PDSCH scheduling objective

[0158] TC-RNTI: UE-specific PDSCH scheduling objective

[0159] CS-RNTI: UE-specific PDSCH scheduling objective with semi-static configuration

[0160] RA-RNTI: PDSCH scheduling objective during the random access phase

[0161] P-RNTI: PDSCH scheduling objective for transmission paging

[0162] SI-RNTI: PDSCH scheduling objective for transmitting system information

[0163] RNTI Inter-frame: Used to indicate whether PDSCH is punched.

[0164] TPC-PUSCH-RNTI: Used to indicate power control commands for the PUSCH.

[0165] TPC-PUCCH-RNTI: Used to indicate the power control command of the PUCCH.

[0166] TPC-SRS-RNTI: Used to indicate the power control command of the SRS.

[0167] The DCI format specified above can follow the definitions shown in Table 12 below.

[0168] [Table 12]

[0169]

[0170]

[0171] In 5G, the search space of CORESET p and the aggregation level L in the search space set s can be represented by equation (2), as shown below.

[0172]

[0173] in:

[0174] -L: Aggregation level

[0175] -n CI Carrier index

[0176] -N CCE,p : The total number of CCEs existing in resource p

[0177] -n μ s,f Time slot index

[0178] -M (L) p,s,maxNumber of PDCCH candidates at aggregation level L

[0179] -m snCI =0,...,M (L) p,s,max -1: PDCCH candidate index at aggregation level L

[0180] -i = 0,...,L-1

[0181] - Y p，-1 =n RNTI ≠0, A0=39827, A1=39829, A2=39839, D=6553'; and

[0182] -n RNTI Terminal Identifier

[0183] In the context of a public search space, Y_(p,n) μ s,f The value can correspond to 0.

[0184] Given a UE-specific search space, Y_(p,n) μ s,f The value can correspond to a value that changes depending on the UE's identifier (C-RNTI or ID configured by the base station for the UE) and time index.

[0185] In 5G, because multiple search space sets can be configured with different parameters (e.g., the parameters in Table 10), the set of search space sets monitored by the UE at each time point can vary. For example, if search space set #1 is configured for time slot X and search space set #2 is configured for time slot Y, and X and Y are different, then the UE can monitor both search space set #1 and search space set #2 in a specific time slot, and can monitor only one of search space set #1 and search space set #2 in another specific time slot.

[0186] When multiple search space sets are configured for a UE, the following conditions can be considered in the method for determining the search space set to be monitored by the UE.

[0187] [Condition 1: Limit the maximum number of PDCCH candidates]

[0188] The number of PDCCH candidates that can be monitored in each time slot does not exceed M. μ M μ It can be defined as being configured with a subcarrier spacing of 15±2 μ The maximum number of PDCCH candidates per time slot in a kHz cell, which can be defined in Table 13 below.

[0189] [Table 13]

[0190] μ <![CDATA[Maximum number of PDCCH candidates per slot and per serving cell (M μ )]]> 0 44 1 36 2 22 3 20

[0191] [Condition 2: Limit the maximum number of CCEs]

[0192] The number of CCEs in each time slot that constitutes the entire search space (the total search space refers to the entire set of CCEs corresponding to the joint region of multiple search space sets) does not exceed C. μ C μ It can be defined as being configured with a subcarrier spacing of 15±2 μ The maximum number of CCEs per time slot in a kHz cell, and can be defined in Table 14 below.

[0193] [Table 14]

[0194] μ <![CDATA[Maximum number of CCEs per time slot and per serving cell (C μ )]]> 0 56 1 56 2 48 3 32

[0195] For ease of explanation, the situation where conditions 1 and 2 are satisfied simultaneously at a specific point in time is defined as "condition A". Therefore, not satisfying condition A can mean not satisfying at least one of the above conditions 1 and 2.

[0196] Depending on the configuration of the base station's search space set, condition A may not be met at a specific time point. If condition A is not met at a specific time point, the UE can select and monitor only some search space sets configured to meet condition A at the corresponding time point, and the base station can send PDCCH to the selected search space sets.

[0197] As a method for selecting some search spaces from the entire set of search spaces, the following approach can be followed.

[0198] When condition A of PDCCH is not met at a specific time point (time slot),

[0199] The UE (or base station) can preferentially select from the search space set that exists at the corresponding time, where the search space type is configured as a common search space, rather than the search space set configured as a UE-specific search space.

[0200] When all search space sets configured as a common search space are selected (i.e., if condition A is satisfied even after selecting all search space sets configured as a common search space), the UE (or base station) can select a search space set configured as a UE-specific search space. In this case, when multiple search space sets are configured as UE-specific search spaces, the search space set with a lower search space set index can have a higher priority. Considering the priority, the UE (or base station) can select a UE-specific search space set within the range that condition A is satisfied.

[0201] In 5G, CORESET can be derived from N in the frequency domain. RB CORESET It consists of RBs, and can be composed of N in the time axis. symb CORESET A CCE consists of 1, 2, 3 symbols. A CCE can consist of 6 REGs, and a REG can be defined as 1 RB for 1 OFDM symbol. In a CORESET, REGs can be indexed in time priority order, starting from REG index 0 (lowest RB) of the first OFDM symbol of the CORESET.

[0202] In 5G, both interleaving and non-interleaving methods are supported as transmission methods for PDCCH. The base station can configure whether to send interleaving or non-interleaving for each CORESET to the UE via higher-layer signaling. Interleaving can be performed on a REG bundle basis. A REG bundle can be defined as a set of one or more REGs. Based on whether to perform interleaving or non-interleaving transmission configured from the base station, the UE can determine the CCE-to-REG mapping method in the corresponding CORESET in the following manner, as shown in Table 15 below.

[0203] [Table 15]

[0204]

[0205] The rate matching operation and the punching operation will be described in detail below.

[0206] When the time and frequency resources A for transmitting any symbol sequence A overlap with any time and frequency resource B, rate matching or puncturing operations can be considered as transmission / reception operations of channel A taking into account resource C in the region where resources A and B overlap. The specific operations can be followed as follows.

[0207] Rate matching operation

[0208] The base station can map and transmit channel A only for the remaining resource areas of all resources A to which symbol sequence A will be sent to the UE, excluding resource C, where resource C corresponds to the area overlapping with resource B. For example, when symbol sequence A consists of {symbol #1, symbol #2, symbol #3, and symbol #4}, resource A is {resource #1, resource #2, resource #3, and resource #4}, and resource B is {resource #3 and resource #5}, the base station can sequentially map symbol sequence A to {resource #1, resource #2, and resource #4}, where {resource #1, resource #2, and resource #4} are the remaining resources in resource A excluding {resource #3} corresponding to resource C, and can then transmit symbol sequence A. As a result, the base station can map symbol sequence {symbol #1, symbol #2, and symbol #3} to {resource #1, resource #2, and resource #4} respectively and transmit it.

[0209] The UE can determine resources A and B based on scheduling information from the base station for symbol sequence A, and through this, the UE can determine resource C, which is the overlapping area of ​​resources A and B. The UE can receive symbol sequence A, assuming that symbol sequence A is sequentially mapped to all remaining areas of resource A except resource C and transmitted. For example, when symbol sequence A consists of {symbol #1, symbol #2, symbol #3, and symbol #4}, resource A is {resource #1, resource #2, resource #3, and resource #4}, and resource B is {resource #3 and resource #5}, the UE can assume that symbol sequence A is sequentially mapped to {resource #1, resource #2, resource #4} (which are the remaining resources in resource A except for {resource #3} corresponding to resource C) for reception. As a result, the UE can assume that symbol sequence {symbol #1, symbol #2, symbol #3} is mapped to {resource #1, resource #2, resource #4} and transmitted, and can perform a series of subsequent reception operations.

[0210] Drilling operation

[0211] When there is a resource C in all resources A used to transmit symbol sequence A to the UE that overlaps with resource B, the base station can map symbol sequence A to the entire resource A, but can not perform transmission in the resource area corresponding to resource C, and can only perform transmission in the remaining resource areas of resource A other than resource C. For example, when symbol sequence A consists of {symbol #1, symbol #2, symbol #3, and symbol #4}, resource A is {resource #1, resource #2, resource #3, and resource #4}, and resource B is {resource #3 and resource #5}, the base station can map symbol sequence A {symbol #1, symbol #2, symbol #3, and symbol #4} to resource A {resource #1, resource #2, resource #3, and resource #4} respectively. It can send only the symbol sequence {symbol #1, symbol #2, and symbol #4} corresponding to {resource #1, resource #2, and resource #4}. {resource #1, resource #2, and resource #4} corresponds to the remaining resources in resource A except for {resource #3} corresponding to resource C, and it is not necessary to send {symbol #3} mapped to {resource #3} corresponding to resource C. As a result, the base station can map the symbol sequence {symbol #1, symbol #2 and symbol #4} to {resource #1, resource #2 and resource #4} respectively and send the symbol sequence {symbol #1, symbol #2 and symbol #4}.

[0212] The UE can determine resources A and B based on scheduling information for symbol sequence A from the base station, and thereby determine resource C, where resource C is the overlapping area of ​​resources A and B. The UE can assume that symbol sequence A is mapped and transmitted in all remaining areas of resource A except for resource C to receive symbol sequence A. For example, when symbol sequence A consists of {symbol #1, symbol #2, symbol #3, and symbol #4}, resource A is {resource #1, resource #2, resource #3, and resource #4}, and resource B is {resource #3 and resource #5}, the UE can assume that symbol sequence A {symbol #1, symbol #2, symbol #3, and symbol #4} is each mapped to resource A {resource #1, resource #2, resource #3, and resource #4}, but {symbol #3} mapped to {resource #3} corresponding to resource C is not sent. The UE can receive the symbol sequence {symbol #1, symbol #2, and symbol #4} corresponding to {resource #1, resource #2, and resource #4}, which is the remaining resource besides {resource #3}. As a result, the UE can assume that the symbol sequence {symbol #1, symbol #2, symbol #3} is mapped to {resource #1, resource #2, resource #4} and sent, and can perform a series of subsequent receiving operations.

[0213] The following describes a method for configuring rate matching resources in a 5G communication system for rate matching purposes. Rate matching refers to adjusting the signal size taking into account the amount of resources available for signal transmission. For example, rate matching of a data channel may refer to adjusting the data size accordingly without mapping and transmitting data channels in specific time and frequency resource areas.

[0214] Figure 6 This is a diagram illustrating a method by which a base station and a UE, according to an embodiment, transmit and receive data, taking into account downlink data channel and rate matching resources.

[0215] refer to Figure 6 The diagram illustrates PDSCH 601 and rate matching resource 602. The base station can configure rate matching resource 602 for the UE via higher-layer signaling (e.g., RRC signaling). The rate matching resource 602 configuration information may include time-domain resource allocation information 603, frequency-domain resource allocation information 604, and periodic information 605. The bitmap corresponding to frequency-domain resource allocation information 604 may be referred to as the "first bitmap," the bitmap corresponding to time-domain resource allocation information 603 may be referred to as the "second bitmap," and the bitmap corresponding to periodic information 605 may be referred to as the "third bitmap." When all or part of the time and frequency resources of the scheduled data channel 601 overlap with the configured rate matching resource 602, the base station can rate match and transmit the data channel 601 within the portion of rate matching resource 602, and the UE can perform reception and decoding assuming that the data channel 601 has been rate matched within the portion of rate matching resource 602.

[0216] The base station can dynamically notify the UE via DCI whether to perform rate matching for the data channel in the configured rate matching resource section through additional configuration (corresponding to the "rate matching indicator" in the DCI format above). Specifically, the base station can select some configured rate matching resources and group them into rate matching resource groups, and can use a bitmap method to indicate to the UE via DCI whether to perform rate matching for the data channel in each rate matching resource group. For example, when four rate matching resources (RMR#1, RMR#2, RMR#3, and RMR#4) are configured, the base station can configure RMG#1 = {RMR#1, RMR#2} and RMG#2 = {RMR#3, RMR#4} as rate matching groups, and can use a 2-bit bitmap in the DCI field to indicate to the UE whether the rate is matched in RMG#1 and RMG#2 respectively. For example, when rate matching is to be performed, it can indicate "1", and when rate matching is not performed, it can indicate "0".

[0217] 5G supports both "RB symbol level" and "RE level" granularity as a method for configuring the aforementioned rate matching resources for the UE. More specifically, the following configuration method can be followed.

[0218] RB symbol level

[0219] For each BWP configured via higher-level signaling, the UE can receive up to four RateMatchPatterns, and a RateMatchPattern can include the following.

[0220] - Reserved resources in a BWP can include resources where the corresponding time and frequency resource regions are configured as a combination of RB-level bitmaps and symbol-level bitmaps on the frequency axis. Reserved resources can span one or two time slots. A time-domain pattern (periodicityAndPattern) can be additionally configured, where the time and frequency domains, consisting of each RB-level and symbol-level bitmap pair, are repeated.

[0221] - This may include time-domain and frequency-domain resource regions configured as CORESET in BWP, as well as resource regions corresponding to time-domain modes configured as search space configurations, wherein the resource regions are repeated in the time-domain mode.

[0222] RE Level

[0223] The UE can receive the following content configured via higher-layer signaling.

[0224] - The configuration information (LTE-CRS-ToMatchAround) used for the RE corresponding to the LTE CRS mode may include the number of LTE CRS ports (nrofCRS-Ports) and the LTE-CRS-vshift(s) value (v-shift), the center subcarrier location information (carrierFreqDL) of the LTE carrier from the reference frequency point (e.g., reference point A), the bandwidth information (carrierBandwidthDL) of the LTE carrier, and the subframe configuration information (mbsfn-SubframConfigList) corresponding to the Multicast-Broadcast Single Frequency Network (MBSFN). The UE can determine the position of the CRS in the NR slot corresponding to the LTE subframe based on the above information.

[0225] - This can include configuration information for one or more resource sets corresponding to ZP CSI-RS in the BWP.

[0226] The rate matching process for LTE CRS described above will be described in detail below. For LTE and NR coexistence (LTE-NR coexistence), NR provides the NR UE with the function of configuring the LTE CRS mode. More specifically, the CRS mode can be provided by RRC signaling, which includes at least one parameter in the ServingCellConfig Information Element (IE) or the ServingCellConfigCommon IE. Examples of this parameter may include lte-CRS-ToMatchAround, lte-CRS-PatternList1-r16, lte-CRS-PatternList2-r16, and CRS-RateMatch-PerCORESETPoolIndex-r16.

[0227] Rel-15 NR provides the functionality to configure one CRS pattern for each serving cell via the lte-CRS-ToMatchAround parameter. In Rel-16 NR, this functionality has been extended to allow configuration of multiple CRS patterns for each serving cell. More specifically, one CRS pattern can be configured per LTE carrier in a UE with a single TRP (Transmit and Receive Point) configuration, one CRS pattern can be configured per LTE carrier in a UE with multiple TRP configurations, and two CRS patterns can be configured per LTE carrier. For example, in a UE with a single TRP configuration, up to three CRS patterns can be configured per serving cell via the lte-CRS-PatternList1-r16 parameter. Additionally or alternatively, CRS can be configured for each TRP in a UE with multiple TRP configurations. That is, a CRS pattern for TRP1 can be configured via the lte-CRS-PatternList1-r16 parameter, and a CRS pattern for TRP2 can be configured via the lte-CRS-PatternList2-r16 parameter. On the other hand, when two TRPs are configured as described above, whether the CRS modes of both TRP1 and TRP2 are applied to a specific PDSCH or only the CRS mode of one TRP is applied is determined by the CRS-RateMatch-PerCORESETPoolIndex-r16 parameter. If the CRS-RateMatch-PerCORESETPoolIndex-r16 parameter is configured to be enabled, only one TRP CRS mode is applied, and in other cases, both TRP CRS modes are applied.

[0228] Table 16 below shows the ServingCellConfig IE including CRS mode, and Table 17 below shows the RateMatchPatternLTE-CRS IE including at least one parameter of CRS mode.

[0229] [Table 16]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235] [Table 17]

[0236]

[0237] As described above, in a UE with a single TRP configuration, only one CRS mode can be configured per LTE carrier. Therefore, in a multi-cell environment, when (multiple) neighboring LTE cells use a different CRS mode than the UE's serving cell (LTE-NR coexisting cell), the UE may receive significant interference from (multiple) neighboring LTE cells. In the above problem, interference to the UE can be reduced through appropriate scheduling of the base station; however, scheduling is performed on a RB-by-RB basis, and CRS is mapped on a RE-by-RE basis, thus presenting limitations. Below, this disclosure proposes a method for minimizing interference from (multiple) neighboring LTE cells in a multi-cell environment as described above.

[0238] “Example 1” can refer to an example of configuring multiple CRS mode information for (multiple) adjacent LTE cells.

[0239] NR base stations can configure CRS mode information for (multiple) neighboring LTE cells for NR UEs.

[0240] In addition to the CRS mode information of the serving cell (LTE-NR coexisting cell), the NR base station can also configure the CRS mode information of (multiple) neighboring LTE cells for the NR UE.

[0241] The CRS mode information configured by the NR base station for the NR UE may include the CRS mode information of the serving cell (LTE-NR coexisting cell) and (multiple) neighboring LTE cells.

[0242] CRS mode information may include an indicator of whether the corresponding CRS mode is used for the serving cell or neighboring LTE cells. Alternatively, it may include an indicator indicating whether the corresponding CRS mode is used for rate matching or interference cancellation.

[0243] Configuration information can be sent from the NR base station to the NR UE via higher-level signaling (e.g., RRC signaling).

[0244] The NR base station can receive CRS mode-related information (e.g., LTE cell ID, number of CRS transmission ports, etc.) from each of the neighboring base stations. shift (and / or transmit power). The NR base station can select at least one LTE serving cell from among multiple LTE serving cells, and can generate CRS mode information to be configured in the UE based on the CRS mode information of the selected multiple LTE serving cells. In the process of selecting at least one LTE serving cell from among multiple LTE serving cells, multiple LTE serving cells with high transmit power can be preferentially selected. The NR base station can send the generated information to the NR UE to configure the CRS mode of the multiple LTE cells adjacent to the NR UE.

[0245] The NR base station can receive information from the UE (e.g., a UE that supports both LTE and NR) about the UE's(s) neighboring LTE serving cells(s) existing in the same frequency band as the serving cell configured in the UE (e.g., LTE cell ID, number of CRS transmission ports, etc.). shift (and / or received power). The NR base station can select at least one LTE serving cell from among multiple LTE serving cells, and can generate CRS mode information to be configured in the UE based on the CRS mode information of the selected multiple LTE serving cells. In the process of selecting at least one LTE serving cell from among multiple LTE serving cells, multiple LTE serving cells with high received power can be preferentially selected. The NR base station can send the generated information to the UE to configure the CRS mode of the multiple LTE cells adjacent to the UE.

[0246] NR UE can receive at least one CRS mode information from the serving cell (LTE-NR coexisting cell) and (multiple) neighboring LTE cells, and can demap PDSCH based on at least one received CRS mode information through rate matching. This is a method in which PDSCH is not mapped to a specific RE that maps (multiple) CRSs based on CRS mode information.

[0247] The NR UE can receive at least one CRS mode information from the serving cell (LTE-NR coexisting cell) and (multiple) neighboring LTE cells, and can demap the PDSCH by interference cancellation based on at least one received CRS mode information. This is a method of mapping the PDSCH to a specific RE that maps (multiple) CRSs based on the CRS mode information.

[0248] The NR UE can receive at least one CRS mode information from the serving cell (LTE-NR coexisting cell) and (multiple) neighboring LTE cells, and can demap the received PDSCH by performing rate matching based on the CRS mode information of the serving cell (LTE-NR coexisting cell), and can demap the received PDSCH by performing interference cancellation based on the CRS mode information of (multiple) neighboring LTE cells.

[0249] NR base stations can generate CRS mode information for the serving cell (LTE-NR coexisting cell) and (multiple) neighboring LTE cells through higher-level signaling (e.g., RRC signaling) and send it to the UE. They can determine the REs that (multiple) CRSs can be mapped to through the CRS mode information, determine whether to map the PDSCH to (multiple) REs, and map and send the PDSCH to the UE based on this determination.

[0250] In (multiple) REs, the NR base station can determine whether the PDSCH maps to (multiple) REs to which the CRS is mapped in the serving cell (LTE-NR coexisting cell) using a rate matching method, and maps to (multiple) REs to which the CRS is mapped in (multiple) neighboring LTE cells using an interference cancellation method.

[0251] According to the disclosure, in multiple REs, the NR base station can determine whether the PDSCH is mapped to the multiple REs to which the CRS used in the serving cell (LTE-NR coexisting cell) is mapped using a rate matching method, and whether the multiple REs to which the CRS used in the multiple neighboring LTE cells is mapped are used for interference cancellation and may not involve PDSCH mapping. In other words, the PDSCH is not mapped to the multiple REs to which the CRS used in the serving cell (LTE-NR coexisting cell) is mapped, and the PDSCH can be mapped to the CRS used in the multiple neighboring LTE cells.

[0252] Figure 7A This is a diagram illustrating the operation of an NR base station according to an embodiment.

[0253] refer to Figure 7AIn step 711, the NR base station obtains CRS mode-related information of (multiple) neighboring serving cells. In step 712, it generates configuration information based on the obtained information and sends the generated configuration information to the UE in step 713. In step 714, the NR base station performs RE mapping to the PDSCH of the UE based on the configuration information and sends the PDSCH in step 715.

[0254] Figure 7B This is a diagram used to illustrate the operation of the NR UE according to an embodiment.

[0255] refer to Figure 7B In step 721, the NR UE receives CRS mode-related configuration information from the base station. Subsequently, in step 722, the UE receives the PDSCH sent from the base station, and in step 723, selectively performs interference cancellation operations based on the received CRS mode configuration information. For example, interference cancellation operations can be performed on specific (multiple) REs.

[0256] “Example 2” may refer to an embodiment that includes an interference cancellation method.

[0257] The information about a neighboring LTE cell in the CRS mode information about (multiple) neighboring LTE cells sent by the NR base station to the NR UE in Example 1 may include at least a portion of the list shown in Table 18 below.

[0258] [Table 18]

[0259]

[0260] In Example 1, the information about one neighboring LTE cell in the CRS mode information about (multiple) neighboring LTE cells sent by the NR base station to the NR UE may include at least a portion of the list shown in Table 19 below. The NR UE can obtain v by performing a "mod 6" calculation on the cell ID value of the neighboring LTE cell. shift (v-Shift) value.

[0261] [Table 19]

[0262]

[0263] In Example 1, the information about one neighboring LTE cell in the CRS mode information about (multiple) neighboring LTE cells sent by the NR base station to the NR UE may include at least a portion of the list shown in Table 20 below. The NR UE may assume that the cell ID of (multiple) neighboring LTE cells is the same as the cell ID of the NR cell, and that the cyclic prefix of the neighboring LTE cells is a regular CP.

[0264] [Table 20]

[0265]

[0266]

[0267] Assuming the LTE radio frame boundaries and NR radio frame boundaries of the serving cell (LTE-NR coexisting cell) are aligned, the NR UE can determine the slot index in the LTE radio frame and the OFDM symbol index in the slot. Alternatively, if they are not aligned, the base station can signal the offset to the UE (this offset is, for example, a value per NR slot or per LTE slot), and the UE can determine the slot index in the LTE radio frame and the OFDM symbol index in the slot based on this signaling. Alternatively, the base station can signal whether they are aligned, and when they are not aligned, it can further signal the offset (this offset is, for example, a value in NR slots or in LTE slots). Alternatively, if the offset is not signaled, the NR UE can operate assuming the LTE radio frame boundaries and NR radio frame boundaries of the serving cell (LTE-NR coexisting cell) are aligned.

[0268] The information about one neighboring LTE cell in the CRS mode information about (multiple) neighboring LTE cells sent by the NR base station to the NR UE in Example 1 may include at least a portion of the list in Table 21.

[0269] [Table 21]

[0270]

[0271] As described above, a UE receiving information about (multiple) neighboring LTE cells can generate (multiple) sequences of (multiple) CRSs (Common Reference Streams) for (multiple) neighboring LTE cells based on the received information, and can obtain time-frequency resource mapping information about the CRSs. In this case, the CRS sequences can be generated as follows. In this scenario, m can be the index of the RB (Resource Block) to which the CRS is mapped.

[0272] Reference signal sequence Defined by the following equation (3).

[0273]

[0274] Where n s `l` is the time slot number within the radio frame, and `l` is the OFDM symbol number within the time slot. The pseudo-random sequence `c(i)` is defined in Section 7.2. The pseudo-random sequence generator will use `c(i)` at the beginning of each OFDM symbol... Initialization, where

[0275]

[0276] Based on the CRS sequence obtained in the above-described manner and the time-frequency resource mapping information of the adjacent LTE cells, the channel between the adjacent LTE cells and the UE can be estimated according to the received CRS signals of the adjacent LTE cells. Because the received CRS signal may be mixed with the PDSCH transmission signal of the NR cell due to interference, a continuous interference cancellation (SIC) process may be needed to handle the interference. The SIC process can be configured as follows, or it can be configured in other ways.

[0277] The received signal y of the UE can be described by the following equation (4):

[0278] y = h NR-UE x PDSCH +h LTE-UE x CRS +n......Equation (4)

[0279] in:

[0280] h NR-UE It is the channel between the NR cell and the UE, and it is a value that the UE obtains in advance through PDSCHDM-RS, etc.

[0281] x PDSCH It is data transmitted in the NR cell, and the value is unknown to the UE;

[0282] h LTE-UE It is the channel between adjacent LTE cells and the UE, and it is a value unknown to the UE;

[0283] x CRS It is the CRS signal of the adjacent LTE cell, which is a value obtained in advance by the UE; and

[0284] n is the noise signal.

[0285] In x CRS The received power is greater than x PDSCH Under the assumption of the received power, the UE can perform the following three (3) steps.

[0286] Step 1.h LTE-UE Channel estimation: At this point, because we assume hN R-UE x PDSCH Because of interference, the SINR of the signal to be estimated, i.e., the channel value, is... If this value is not too low, the UE can obtain h. LTE-UE value.

[0287] Step 2. h can be subtracted from the received signal y. LTE-UEx CRS The remaining signal is...

[0288] Step 3.x PDSCH Signal Decoding: At this point, the SNR of the signal to be decoded is... If this value is not too low, the UE may be able to decode successfully.

[0289] Figure 8 This is a diagram used to illustrate the operation of the NR UE according to an embodiment.

[0290] refer to Figure 8 In step 801, the NR UE receives CRS mode-related configuration information from the base station. Then, in step 802, the NR UE receives PDSCH. In step 803, the NR UE generates multiple sequences of CRS based on the CRS mode-related configuration information obtained in step 801, and determines the multiple REs to which the multiple CRSs are mapped. Furthermore, in step 804, the NR UE performs decoding through the SIC procedure.

[0291] “Example 3” may refer to an example describing the classification of interference cancellation / rate matching operations.

[0292] The classification of capabilities through the UE will now be described.

[0293] UE capability information for interference cancellation can be defined as in the first and second embodiments. An NR UE can receive a "UECapabilityEnquiry" message from the NR base station and respond to the NR base station with a message including "UE capability information for interference cancellation". Based on the "UE capability information for interference cancellation" in the UE's response, the NR base station can configure UEs capable of interference cancellation to perform interference cancellation, and can configure UEs incapable of interference cancellation to perform rate matching.

[0294] Figure 9A This is a diagram illustrating the operation of an NR base station according to an embodiment.

[0295] refer to Figure 9A In step 911, the NR base station sends a "UECapabilityEnquiry" message to the NR UE, and in step 912, it receives a "UE Capability" message from the UE regarding interference cancellation capabilities. In step 913, based on the UE Capability message, the NR base station configures the UE's operations (interference cancellation and rate matching). Furthermore, the NR base station can generate CRS mode information for (multiple) neighboring serving cells and configure the CRS mode information in the UE.

[0296] Figure 9BThis is a diagram used to illustrate the operation of the NR UE according to an embodiment.

[0297] refer to Figure 9B In step 921, the NR receives a "UECapabilityEnquiry" message from the NR base station, and in step 922, sends a "UE Capability" message regarding interference cancellation capabilities to the base station. Furthermore, in step 923, the NR UE receives UE operation (interference cancellation, rate matching) configuration information from the base station and can operate according to this configuration information. Additionally, the NR UE can receive CRS mode configuration information from (multiple) neighboring serving cells from the base station.

[0298] The NR UE can operate in a conventional manner before receiving information configurations from (multiple) neighboring LTE cells in the first and second embodiments. That is, it can be assumed that the NR PDSCH is mapped to a RE used to transmit CRS in (multiple) neighboring LTE cells to perform operations. The NR UE can receive information configurations from (multiple) neighboring LTE cells in the first and second embodiments. Based on this configuration, the NR UE can identify the RE transmitting CRS in (multiple) neighboring LTE cells, and if the NR PDSCH is not mapped to the identified RE, it can perform rate matching operations. The NR UE can receive a "UECapabilityEnquiry" message from the NR base station and can respond to the NR base station with UE capability information including interference cancellation for the first and second embodiments. Thereafter, the UE can operate according to the UE capability information. In other words, if interference cancellation is not possible, the UE can later identify (multiple) REs used to transmit CRS in (multiple) neighboring LTE cells based on the information configuration of (multiple) neighboring LTE cells, assuming that the NR PDSCH is not mapped to the identified (multiple) REs, and can perform rate matching operations. On the other hand, if interference cancellation is possible, the UE can later identify (multiple) REs used to transmit CRS in (multiple) neighboring LTE cells based on the information configuration of (multiple) neighboring LTE cells, assuming that the NR PDSCH is mapped to the identified (multiple) REs, and can perform interference cancellation operations according to the first and second embodiments. Table 22 shown below is an example of UE operation and illustrates the above description.

[0299] [Table 22]

[0300]

[0301] The NR UE can operate in a conventional manner before receiving information configurations from (multiple) neighboring LTE cells in the first and second embodiments. That is, it can be assumed that the NR PDSCH is mapped to (multiple) REs used to transmit CRS in (multiple) neighboring LTE cells to perform the operation. The NR UE can receive information configurations from (multiple) neighboring LTE cells in the first and second embodiments. Based on this configuration, the NR UE can identify (multiple) REs transmitting CRS in (multiple) neighboring LTE cells based on the information configuration information from (multiple) neighboring LTE cells, and can assume that the NR PDSCH is not mapped to the identified (multiple) REs, and can perform rate matching operations. The NR UE can receive a "UECapabilityEnquiry" message from the NR base station and can respond to the NR base station with UE capability information including interference cancellation for the first and second embodiments. The NR base station can receive the UE capability information for interference cancellation from the UE and can send configuration information to the UE for subsequent operations (i.e., whether to perform rate matching operations or interference cancellation operations). The configuration information can be sent to the UE via higher-layer signaling (RRC), MAC CE, or DCI. Afterward, the UE can operate according to the base station's configuration information. Table 23 below shows an example of UE operation and illustrates the above description.

[0302] [Table 23]

[0303]

[0304] The difference between the indicated interference cancellation mode and the rate matching mode will now be described.

[0305] The CRS mode information configured by the NR base station for the NR UE may include CRS mode information for the serving cell (LTE-NR coexisting cell) and (multiple) neighboring LTE cells. The base station may send control signals to the UE corresponding to at least some operations (e.g., rate matching, interference cancellation, and legacy behavior) for each CRS mode information. These control signals can be sent to the UE via higher-layer signaling (RRC), MAC CE, or DCI. The UE can perform operations based on a combination of at least one or more control signals.

[0306] For RRC-based configurations, the NR UE can receive CRS mode information and operation indication (interference cancellation indication) information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). Upon receiving this information, the NR UE can perform interference cancellation operations on the RE(multiple) mapped to the CRS of neighboring LTE cell A based on the receive control information.

[0307] The NR UE can receive CRS mode information and operation indication (rate matching indication) information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). Upon receiving this information, the NR UE can perform rate matching operations on the RE(multiple) mapped to the CRS of neighboring LTE cell A based on the receive control information.

[0308] The NR UE can receive CRS mode information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). In this case, the UE can assume that the base station implicitly indicates interference cancellation and can perform interference cancellation operations on the RE(multiple) mapped to the CRS of neighboring LTE cell A based on the receive control information.

[0309] The NR UE can receive CRS mode information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). In this case, the UE can assume that the base station implicitly indicates interference cancellation and can perform rate matching operations on the RE(multiple) mapped to the CRS of neighboring LTE cell A based on the receive control information.

[0310] Unlike the RateMatchPatternLTE-CRS IE in Table 2, the CRS pattern information of neighboring LTE cells or the list of CRS pattern information of neighboring LTE cells can be indicated to the UE by a separate IE that includes at least some lists (such as the lists provided in Tables 18-21).

[0311] Figure 10A This is a diagram used to illustrate the operation of the NR UE according to an embodiment.

[0312] refer to Figure 10A In step 1011, the NR UE receives CRS mode information of (multiple) neighboring cells from the base station via an RRC message. Operation indication (interference cancellation or rate matching) information may be additionally included in the RRC configuration message. Alternatively, the operation indication (interference cancellation or rate matching) information may be included in a separate RRC configuration message. Additionally, the operation in the case of receiving CRS mode information of (multiple) neighboring cells may be implicitly provided. Furthermore, the operation in the case of receiving CRS mode information of (multiple) neighboring cells may be implicitly provided according to the UE's capabilities. In step 1012, the UE performs interference cancellation or rate matching operation based on the received RRC configuration information.

[0313] The configuration based on RRC+L1 / L2 will now be described.

[0314] The NR UE can receive CRS mode information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). Additionally, the NR UE can receive operation instruction (interference cancellation instruction) information from the NR base station via, for example, MAC CE or DCI. Upon receiving this information, the NR UE can perform interference cancellation operations on the RE(multiple) mapped to the CRS of neighboring LTE cell A based on the receive control information. Before receiving the operation instruction (interference cancellation instruction) information, the UE can operate under the assumption of rate matching. The aforementioned operation instruction information can be newly defined in the MAC CE or newly defined in the DCI format. When the operation instruction (interference cancellation instruction) information is defined in the DCI format, the size of the field containing the operation instruction (interference cancellation instruction) information can be based on the number of neighboring LTE cell CRS mode information configured via higher-layer signaling. That is, when information from two neighboring cells is received, it can be 2 bits, and when information from three neighboring cells is received, it can be 3 bits. Thus, the base station can instruct the UE to independently process each of the RE(multiple) mapped to the CRS of neighboring LTE cells.

[0315] The NR UE can receive CRS mode information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). Additionally, the NR UE can receive operation instruction (rate matching instruction) information from the NR base station via, for example, MAC CE or DCI. Upon receiving this information, the NR UE can perform rate matching operations on the RE(multiple) to which the CRS of neighboring LTE cell A is mapped, based on the receive control information. Before receiving the operation instruction (rate matching instruction) information, the UE can operate under the assumption of rate matching. The aforementioned operation instruction information can be newly defined in the MAC CE or newly defined in the DCI format. When the operation instruction (rate matching instruction) information is newly defined in the DCI format, the size of the field containing the operation instruction (rate matching instruction) information can be based on the number of neighboring LTE cell CRS mode information configured via higher-layer signaling. That is, when information from two neighboring cells is received, it can be 2 bits, and when information from three neighboring cells is received, it can be 3 bits. Thus, the base station can instruct the UE to independently process each of the RE(multiple) to which the CRS of neighboring LTE cells is mapped.

[0316] The NR UE can receive CRS mode information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). Additionally, the NR UE can receive operation instruction (interference cancellation and rate matching) information (1 bit) from the NR base station via, for example, MAC CE or DCI. Upon receiving this information, the NR UE can perform interference cancellation or rate matching operations on the RE(multiple) mapped to the CRS of neighboring LTE cell A based on the receive control information. Before receiving the operation instruction (rate matching instruction) information, the UE can operate under the assumption of rate matching. The aforementioned operation instruction information can be newly defined in the MAC CE or newly defined in the DCI format. When the operation instruction (interference cancellation and rate matching) information is defined in the DCI format, the size of the field containing the operation instruction (interference cancellation and rate matching) information can be based on the number of neighboring LTE cell CRS mode information configured via higher-layer signaling. That is, when information from two neighboring cells is received, it can be 2 bits, and when information from three neighboring cells is received, it can be 3 bits. Thus, the base station can instruct the UE to independently process each of the (multiple) REs to which the CRS of the adjacent LTE cell is mapped.

[0317] The NR UE can receive CRS mode information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). Additionally, the NR UE can receive operation indication (interference cancellation and rate matching) information from the NR base station via DCI. The operation indication information can be indicated by the values ​​of at least some of the fields (multiple) already present in the DCI format. For example, the values ​​of the modulation and coding scheme field in the DCI format can be used. Assuming the value of this field ranges from 0 to 31, when a value below a certain value is indicated to the UE via the DCI format, the UE can interpret it as an interference cancellation indication and perform the operation; and when a value above or equal to the certain value is indicated to the UE via the DCI format, the UE can interpret it as a rate matching indication and perform the operation. Conversely, when a value below a certain value is indicated to the UE via the DCI format, the UE can interpret it as a rate matching indication and perform the operation; and when a value above or equal to the certain value is indicated to the UE via the DCI format, the UE can interpret it as an interference cancellation indication and perform the operation. At this point, the NR UE can process all configured REs mapped to the CRS of all neighboring LTE cells in the same way (i.e., all interference cancellation or all rate matching). This specific value can be predefined through NR standard documents (i.e., pre-stored in the UE) or sent to the UE through control information configured for the UE by the NR base station (e.g., RRC settings).

[0318] The NR UE can receive CRS mode information of neighboring LTE cell A from the NR base station via higher-layer signaling (e.g., RRC signaling). Additionally, the NR UE can receive operation indication (interference cancellation and rate matching) information from the NR base station via DCI. The operation indication information can be indicated by the values ​​of at least some of the fields (multiple fields) already present in the DCI format.

[0319] For example, the value of the DMRS sequence initialization field in the DCI format can be used. When 0 is indicated as the field value, the UE can understand and operate to configure the PDSCH DMRS sequence initialization value corresponding to the field value, and also indicate rate matching for CRS. Similarly, when 1 is indicated as the field value, the UE can understand and operate to configure the PDSCH DMRS sequence initialization value corresponding to that field value, and also indicate interference control for CRS (and vice versa). In this case, the NR UE can process all configured REs mapped to CRS for all neighboring LTE cells in the same way (i.e., full interference cancellation or full rate matching). The mapping between the DMRS sequence initialization field value and the rate matching or interference control operation for CRS can be predefined in the NR standard document (i.e., pre-stored in the UE), or sent to the UE via control information configured for the UE by the NR base station (e.g., RRC settings).

[0320] Figure 10B This is a diagram used to illustrate the operation of the NR UE according to an embodiment.

[0321] refer to Figure 10B In step 1021, the NR UE receives CRS mode information from (multiple) neighboring cells from the base station via RRC messages. In step 1022, the NR UE receives DCI from the base station and performs interference cancellation or rate matching operations based on the operation instruction information included in the DCI. Alternatively, the operation instruction information can be received via MAC CE instead of DCI.

[0322] Several TRP scenarios will now be described.

[0323] An NR UE receiving data from multiple TRPs can determine whether to perform interference cancellation or rate matching for each TRP based on the type of the TRP. For example, if each of the multiple TRPs points to a base station in an LTE-NR coexisting cell, rate matching for CRS might be necessary because the interference signal strength received from the TRP closest to the UE is significantly greater than the NR signal strength. On the other hand, because the ratio of NR signal strength to CRS signal strength from the remaining TRPs might be relatively small, CRS interference cancellation might be appropriate. Or conversely, performing CRS interference cancellation from the nearest TRP and rate matching from the remaining TRPs might be appropriate. Therefore, an NR UE can remove a CRS from a specific TRP by performing interference cancellation, and rate matching can be performed on CRS from another TRP.

[0324] At this point, the TRP for performing CRS interference cancellation and CRS rate matching operations can be predefined in the NR standard document (i.e., pre-stored in the UE), or delivered to the UE via control information configured for the UE by the NR base station (e.g., RRC settings). The TRP defined above or configured via control information can be represented as an index value configured for each CORESET, such as the CORESETPoolIndex value, Physical Cell ID (PCID), and / or SSB index. CRS rate matching operations can be applied to CORESETs configured with CORESETPoolIndex = 0, and CRS interference cancellation operations can be applied to CORESETs configured with CORESETPoolIndex = 1.

[0325] Figure 11 This is a diagram used to illustrate the operation of the NR UE according to an embodiment.

[0326] refer to Figure 11 In step 1101, the NR UE receives configuration information for each TRP from the base station. Then, in step 1102, the UE receives PDSCH from multiple TRPs. In step 1103, based on the configuration information received from the base station, the UE performs interference cancellation or rate matching operations for each TRP of each received PDSCH.

[0327] IV. The operations in MBSFN will now be described.

[0328] The NR UE can receive the mbsfn-SubframeConfigList from the NR base station via the RateMatchPatternLTE-CRS IE in Table 2, and can identify time slots corresponding to (overlapping with) MBSFN subframes in LTE within the time slots of the serving cell (LTE-NR coexisting cell). Interference cancellation according to the above embodiments may not be performed in the identified time slots. Rate matching operations can be performed in the identified (multiple) time slots. Alternatively, rate matching can be performed only on (multiple) CRS REs present in the MBSFN subframes.

[0329] The NR UE can receive the "mbsfn-SubframeConfigList" from (multiple) neighboring LTE cells from the NR base station and can identify (overlapping) time slots corresponding to MBSFN subframes in LTE within the time slots of the serving cell (LTE-NR coexisting cell). Interference cancellation may not be performed in the identified time slots. Rate matching operations may be performed in the identified (multiple) time slots. Alternatively, rate matching may be performed only on (multiple) CRS REs present in the MBSFN subframes.

[0330] “Example 4” may refer to an embodiment in which NR PDSCH mapping is performed only at (multiple) CRS REs in some time slots.

[0331] In the above embodiments, the mapping of NR PDSCH to LTE (multiple) CRS REs can be applied to some time slots in the NR time slots. NR PDSCH may not be mapped to LTE (multiple) CRS REs included in the remaining time slots except for some application time slots.

[0332] The NR base station can deliver to the NR UE information about the time slots mapped from the NR PDSCH to (multiple) LTE CRS REs (e.g., at least one of multiple defined time slot patterns and / or a list of time slots). Based on this information, the UE can perform interference cancellation operations according to the above embodiments in the time slots where the NRPDSCH is mapped to (multiple) LTE CRS REs, and perform rate matching operations in the remaining time slots. Furthermore, in the remaining time slots, the NR UE can receive (multiple) LTE CRSs and use (multiple) LTE CRSs to estimate h in equation (2). LTE-UE information.

[0333] The LTE base station can deliver information to the NR UE about the time slots mapped from the NR PDSCH to (multiple) LTE CRS REs (e.g., at least one of multiple defined time slot patterns and / or a list of time slots). Based on this information, the UE can discard (multiple) CRS REs received in the time slots where the mapping from the NR PDSCH to (multiple) LTE CRS REs has been applied, without using them for channel estimation.

[0334] "Example 5" may refer to some or all of the embodiments described above.

[0335] In order to implement the above embodiments of this disclosure, in Figure 12 and 13 The transceivers, memory, and processors of the UE and base station are shown respectively. In the above embodiments, methods for configuring CRS mode information for (multiple) neighboring LTE cells, methods for configuring operations (interference cancellation or rate matching), methods for indicating operations, and methods for exchanging UE capability information are illustrated. Therefore, the transceivers, memory, and processors of the base station and UE must operate according to the above embodiments.

[0336] Figure 12 The structure of the UE according to an embodiment is shown.

[0337] refer to Figure 12 The UE includes a transceiver 1201, a memory 1202, and a processor 1203. However, the components of the UE are not limited to the examples described above. For example, the UE may include more or fewer components than those described above. Furthermore, the transceiver 1201, memory 1202, and processor 1203 may be implemented as a single chip.

[0338] Transceiver 1201 can transmit signals to / receive signals from a base station. These signals may include control information and data. For this purpose, transceiver 1201 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low-noise amplification and down-converting the received signal. Furthermore, transceiver 1201 can receive signals via a wireless channel, output signals to processor 1203, and transmit signals output from processor 1203 via a wireless channel.

[0339] Memory 1202 can store programs and data required for UE operation. Furthermore, memory 1202 can store control information or data included in signals transmitted and received by the UE. Memory 1202 can be configured as a storage medium (such as read-only memory (ROM), random access memory (RAM), hard disk, optical disc (CD)-ROM, and digital multifunction disc (DVD)) or a combination of storage media. Furthermore, memory 1202 can consist of multiple memories and can store programs for removing and decoding interference from one or more REs in the UE's PDSCH.

[0340] The processor 1203 can control a series of processes that the UE can operate according to the above embodiments. For example, the processor 1203 can control the decoding and removal of interference from one or more REREs in the PDSCH.

[0341] Specifically, the processor 1203 can receive CRS mode configuration information from the base station of (multiple) neighboring LTE cells, and can control each configuration of a UE that has interference cancellation operation or rate matching operation in one or more REs in the PDSCH received from the base station based on the CRS mode configuration information from (multiple) neighboring LTE cells of the base station.

[0342] Specifically, the processor 1203 can receive CRS mode configuration information from the base station for (multiple) neighboring LTE cells, and can control each configuration of a UE having interference cancellation operation or rate matching operation in one or more REs in the PDSCH received from the base station based on the CRS mode configuration information of (multiple) neighboring LTE cells and operation indication information delivered by higher-layer signaling or lower-layer signaling (DCI or MAC CE) from the base station.

[0343] Furthermore, the processor 1203 may include multiple processors, and by executing a program stored in the memory 1202, it can perform a method to remove and decode interference from one or more REs in the PDSCH.

[0344] Figure 13 The structure of a base station according to an embodiment is shown.

[0345] refer to Figure 13 The base station includes a transceiver 1301, a memory 1302, and a processor 1303. However, the components of the UE are not limited to the examples described above. For example, the base station may include more or fewer components than those described above. Furthermore, the transceiver 1301, memory 1302, and processor 1303 may be implemented as a single chip.

[0346] Transceiver 1301 can send signals to / receive signals from the UE. These signals may include control information and data. For this purpose, transceiver 1301 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low-noise amplification and down-converting the received signal. Furthermore, transceiver 1301 can receive signals via a wireless channel, output signals to processor 1303, and transmit signals output from processor 1303 via a wireless channel.

[0347] Memory 1302 can store programs and data required for base station operation. Furthermore, memory 1302 can store control information or data included in signals transmitted and received by the base station. Memory 1302 can be configured as a storage medium (such as ROM, RAM, hard disk, CD-ROM, and DVD) or a combination of storage media. Additionally, memory 1302 can consist of multiple memories. Memory 1302 can store programs for generating CRS mode configuration information for (multiple) neighboring LTE cells of the base station and sending information to the UE. Alternatively, memory 1302 can store programs for generating CRS mode configuration information for (multiple) neighboring LTE cells of the base station and sending information to the UE. Additionally, memory 1302 can store programs for generating and transmitting downlink control channels or MAC CEs containing information indicating interference cancellation operations or rate matching operations. Memory 1302 can additionally store data mapping determination programs for (multiple) specific REs in the PDSCH.

[0348] The processor 1303 can control a series of processes that the base station can operate according to the above embodiments of the present disclosure. For example, the processor 1303 can control each configuration of the base station for generating and transmitting CRS mode configuration information of (multiple) neighboring LTE cells, generating and transmitting information indicating interference cancellation operation or rate matching operation, and determining data mapping to (multiple) specific REs in the PDSCH based on the configuration information and operation indication information.

[0349] Furthermore, the processor 1303 may include multiple processors, and by executing programs stored in the memory 1302, it may perform methods for generating and transmitting CRS mode configuration information of (multiple) neighboring LTE cells, methods for instructing interference cancellation operations or rate matching operations, and methods for mapping symbols to (multiple) specific REs in the PDSCH based on configuration information and operation instruction information.

[0350] The methods described in the claims or specification of this disclosure can be implemented by hardware, software, or a combination of hardware and software.

[0351] When these methods are implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors within an electronic device. The at least one program may include instructions causing the electronic device to perform methods according to the various embodiments defined by the appended claims and / or disclosed herein.

[0352] The program (software module or software) can be stored in non-volatile memory, including RAM and flash memory, ROM, electrically erasable programmable ROM (EEPROM), disk storage devices, CD-ROM, DVD, other types of optical storage devices, or magnetic tape. Alternatively, any combination of some or all of the non-volatile memory can form a memory that stores the program. Furthermore, an electronic device may include multiple such memories.

[0353] Furthermore, the program can be stored on an attachable storage device that can be accessed by the electronic device via a communication network, such as the Internet, intranet, local area network (LAN), wide area network (WLAN), storage area network (SAN), or a combination thereof. This storage device can access the electronic device via an external port. Additionally, a standalone storage device on the communication network can access portable electronic devices.

[0354] In the detailed embodiments described above, elements included in this disclosure are represented in a singular or plural form according to the presented embodiments. However, for the sake of convenience, singular or plural forms have been suitably chosen as presented, and this disclosure is not limited to elements expressed in a singular or plural form. Thus, an element represented in a plural form may also include a single element, or an element represented in a singular form may include multiple elements.

[0355] The embodiments of this disclosure described and illustrated in the specification and drawings are merely specific examples presented to readily explain the technical content of this disclosure and aid in understanding it, and are not intended to limit the scope of this disclosure. That is, it will be apparent to those skilled in the art that other variations based on the technical ideas of this disclosure can be implemented. Furthermore, the various embodiments described above can be combined as needed. Moreover, the embodiments of this disclosure can be applied to other communication systems, and other variations based on the technical ideas of the embodiments can also be implemented. For example, the embodiments can be applied to LTE, 5G, and NR systems.

[0356] While this disclosure has been specifically shown and described with reference to certain embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a communication system, the method comprising: Received from the base station via Radio Resource Control (RRC) signaling: Cell-Specific Reference Signal (CRS) mode information of the serving cell, wherein the serving cell is a Long Term Evolution (LTE) - New Radio (NR) coexistence cell, and At least one CRS mode information of at least one neighboring cell, wherein at least one neighboring cell is an LTE cell. The system receives a Media Access Control (MAC) element (CE) from the base station, including a field indicating interference cancellation or rate matching for at least one neighboring cell, wherein the size of the field is based on the amount of at least one CRS mode information from at least one neighboring cell. Based on at least one CRS mode information of at least one neighboring cell, identify the resource elements (REs) of the CRS of at least one neighboring cell. Based on the aforementioned fields, it is determined whether to perform interference cancellation or rate matching to receive the Physical Downlink Shared Channel (PDSCH) on the RE of the CRS in at least one neighboring cell; and Based on the determination, PDSCH is received from the base station. Wherein, if the field indicates interference cancellation for at least one neighboring cell, interference cancellation is performed on the RE of the CRS of the neighboring cell. Wherein, if the field indicates rate matching for at least one neighboring cell, rate matching is performed on the RE of the CRS of the neighboring cells, and Among them, at least one CRS mode information of at least one neighboring cell includes: Information indicating whether the LTE radio frame boundaries and NR radio frame boundaries of the serving cell are aligned, and Information indicating the offset between the LTE radio frame boundaries and NR radio frame boundaries of the serving cell when the LTE radio frame boundaries and NR radio frame boundaries of the serving cell are not aligned.

2. The method according to claim 1, wherein, Receiving the PDSCH based on interference cancellation includes: A CRS sequence is generated based on at least one CRS mode information of the at least one neighboring cell; The channel with the at least one neighboring cell is estimated based on the CRS sequence and the received signals from the at least one neighboring cell; and The PDSCH is received from the base station on the RE of the CRS of the at least one neighboring cell by eliminating the CRS from the received signal based on the CRS sequence and the channel with the at least one neighboring cell.

3. The method according to claim 1, wherein, The decision to perform interference cancellation or rate matching to receive PDSCH on the RE of the CRS of the at least one neighboring cell is based on at least one of the following: Capability information sent to the base station; or Configuration received from the base station based on the capability information.

4. The method according to claim 1, wherein, The decision to perform interference cancellation or rate matching to receive PDSCH on the RE of the CRS of the at least one neighboring cell is based on at least one of the following: The transmit and receive points (TRPs) that send the PDSCH; Multimedia Broadcast Single Frequency Network (MBSFN) subframe configuration; or Defines the configuration for whether the PDSCH is sent on the RE of the CRS in a time slot.

5. A terminal in a communication system, the terminal comprising: transceiver; and The controller is configured as follows: Received from the base station via Radio Resource Control (RRC) signaling: Cell-Specific Reference Signal (CRS) mode information of the serving cell, wherein the serving cell is a Long Term Evolution (LTE) - New Radio (NR) coexistence cell, and At least one CRS mode information of at least one neighboring cell, wherein at least one neighboring cell is an LTE cell. The system receives a Media Access Control (MAC) element (CE) from the base station, including a field indicating interference cancellation or rate matching for at least one neighboring cell, wherein the size of the field is based on the amount of at least one CRS mode information from at least one neighboring cell. Based on at least one CRS mode information of at least one neighboring cell, identify the resource elements (REs) of the CRS of at least one neighboring cell. Based on the aforementioned fields, it is determined whether to perform interference cancellation or rate matching to receive the Physical Downlink Shared Channel (PDSCH) on the RE of the CRS in at least one neighboring cell; and Based on the determination, PDSCH is received from the base station. Wherein, if the field indicates interference cancellation for at least one neighboring cell, interference cancellation is performed on the RE of the CRS of the neighboring cell. Wherein, if the field indicates rate matching for at least one neighboring cell, rate matching is performed on the RE of the CRS of the neighboring cells, and Among them, at least one CRS mode information of at least one neighboring cell includes: Information indicating whether the LTE radio frame boundaries and NR radio frame boundaries of the serving cell are aligned, and Information indicating the offset between the LTE radio frame boundaries and NR radio frame boundaries of the serving cell when the LTE radio frame boundaries and NR radio frame boundaries of the serving cell are not aligned.

6. The terminal according to claim 5, wherein, The interference cancellation-based PDSCH reception includes: A CRS sequence is generated based on at least one CRS mode information of the at least one neighboring cell; The channel with the at least one neighboring cell is estimated based on the CRS sequence and the received signals from the at least one neighboring cell; and By eliminating the CRS from the received signal based on the CRS sequence and the channel with the at least one neighboring cell, the PDSCH is received from the base station on the RE of the CRS of the at least one neighboring cell.

7. The terminal according to claim 5, wherein, The decision to perform interference cancellation or rate matching to receive PDSCH on the RE of the CRS of the at least one neighboring cell is based on at least one of the following: Capability information sent to the base station; or Configuration received from the base station based on the capability information.

8. The terminal according to claim 5, wherein, The decision to perform interference cancellation or rate matching to receive PDSCH on the RE of the CRS of the at least one neighboring cell is based on at least one of the following: The transmit and receive points (TRPs) that send the PDSCH; Multimedia Broadcast Single Frequency Network (MBSFN) subframe configuration; or Defines the configuration for whether PDSCH is sent on the RE of the CRS in a time slot.

9. A method performed by a base station in a communication system, the method comprising: Send to the terminal via Radio Resource Control (RRC) signaling: Cell-Specific Reference Signal (CRS) mode information of the serving cell, wherein the serving cell is a Long Term Evolution (LTE) - New Radio (NR) coexistence cell, and At least one CRS mode information of at least one neighboring cell, wherein at least one neighboring cell is an LTE cell. The terminal sends a Media Access Control (MAC) element (CE) including a field indicating interference cancellation or rate matching for at least one neighboring cell, wherein the size of the field is based on the amount of at least one CRS mode information from at least one neighboring cell. Based on at least one CRS mode information from at least one neighboring cell, identify the resource elements (REs) of the CRS of at least one neighboring cell; and Send the Physical Downlink Shared Channel (PDSCH) to the terminal. Specifically, the PDSCH on the RE of the CRS is associated with interference cancellation or rate matching based on the aforementioned field. Wherein, if the field indicates interference cancellation for at least one neighboring cell, interference cancellation is performed on the RE of the CRS of the neighboring cell. Wherein, if the field indicates rate matching for at least one neighboring cell, rate matching is performed on the RE of the CRS of the neighboring cells, and Among them, at least one CRS mode information of at least one neighboring cell includes: Information indicating whether the LTE radio frame boundaries and NR radio frame boundaries of the serving cell are aligned, and Information indicating the offset between the LTE radio frame boundaries and NR radio frame boundaries of the serving cell when the LTE radio frame boundaries and NR radio frame boundaries of the serving cell are not aligned.

10. The method according to claim 9, wherein, The PDSCH on the RE of the CRS of the at least one neighboring cell is determined to be associated with interference cancellation or rate matching based on at least one of the following: Capability information sent to the base station; or Configuration received from the base station based on the capability information.

11. The method according to claim 9, wherein, The PDSCH on the RE of the CRS of the at least one neighboring cell is determined to be associated with interference cancellation or rate matching based on at least one of the following: The transmit and receive points (TRPs) that send the PDSCH; Multimedia Broadcast Single Frequency Network (MBSFN) subframe configuration; or Defines the configuration for whether PDSCH is sent on the RE of the CRS in a time slot.

12. A base station in a communication system, the base station comprising: transceiver; and The controller is configured as follows: Send to the terminal via Radio Resource Control (RRC) signaling: Cell-Specific Reference Signal (CRS) mode information of the serving cell, wherein the serving cell is a Long Term Evolution (LTE) - New Radio (NR) coexistence cell, and At least one CRS mode information of at least one neighboring cell, wherein at least one neighboring cell is an LTE cell. The terminal sends a Media Access Control (MAC) element (CE) including a field indicating interference cancellation or rate matching for at least one neighboring cell, wherein the size of the field is based on the amount of at least one CRS mode information from at least one neighboring cell. Based on at least one CRS mode information from at least one neighboring cell, identify the resource elements (REs) of the CRS of at least one neighboring cell; and Send the Physical Downlink Shared Channel (PDSCH) to the terminal. Specifically, the PDSCH on the RE of the CRS is associated with interference cancellation or rate matching based on the aforementioned field. Wherein, if the field indicates interference cancellation for at least one neighboring cell, interference cancellation is performed on the RE of the CRS of the neighboring cell. Wherein, if the field indicates rate matching for at least one neighboring cell, rate matching is performed on the RE of the CRS of the neighboring cells, and Among them, at least one CRS mode information of at least one neighboring cell includes: Information indicating whether the LTE radio frame boundaries and NR radio frame boundaries of the serving cell are aligned, and Information indicating the offset between the LTE radio frame boundaries and NR radio frame boundaries of the serving cell when the LTE radio frame boundaries and NR radio frame boundaries of the serving cell are not aligned.

13. The base station according to claim 12, wherein, The PDSCH on the RE of the CRS of the at least one neighboring cell is determined to be associated with interference cancellation or rate matching based on at least one of the following: Capability information sent to the base station; or Configuration received from the base station based on the capability information.

14. The base station according to claim 12, wherein, The PDSCH on the RE of the CRS of the at least one neighboring cell is determined to be associated with interference cancellation or rate matching based on at least one of the following: The transmit and receive points (TRPs) that send the PDSCH; Multimedia Broadcast Single Frequency Network (MBSFN) subframe configuration; or Defines the configuration for whether PDSCH is sent on the RE of the CRS in a time slot.

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