KR20220080654A - Apparatus and method for inter-cell interference management in wireless communication systems - Google Patents

Abstract

The present disclosure relates to a communication technique that converges a 5G communication system for supporting a higher data rate after a 4G system with IoT technology, and a system thereof. The present disclosure provides intelligent services (eg, smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. ) can be applied to In addition, the present disclosure relates to a method and apparatus for performing communication in a wireless communication system composed of multiple cells.

Description

Inter-cell interference control apparatus and method for wireless communication system

The present disclosure relates to a method and apparatus for performing communication in a wireless communication system configured with multiple cells.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system in order to meet the increasing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a 4G network after (Beyond 4G Network) communication system or an LTE system after (Post LTE) system. In order to achieve a high data rate, the 5G communication system is being considered for implementation in a very high frequency (mmWave) band (eg, such as a 60 gigabyte (60 GHz) band). In order to alleviate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud radio access network: cloud RAN), an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Technology development is underway. In addition, in the 5G system, advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), and advanced access technologies such as Filter Bank Multi Carrier (FBMC), NOMA (non orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, in technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication), 5G communication technology is implemented by techniques such as beam forming, MIMO, and array antenna. there will be The application of cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of convergence of 5G technology and IoT technology.

On the other hand, for the coexistence of LTE (Long Term Evolution) and NR (New RAT) (LTE-NR Coexistence), NR provides a function of setting a CRS (Cell Specific Reference Signal) pattern of LTE to an NR terminal. In the Single-TRP configuration terminal, only one CRS pattern per one LTE carrier may be configured. Therefore, in a multi-cell environment, when the adjacent LTE cell(s) uses a different CRS pattern from the terminal's serving cell (LTE-NR coexistence cell), the terminal may receive significant interference from the adjacent LTE cell(s). can experience Although the above problem can reduce interference to the UE through proper scheduling of the base station, scheduling is performed in units of resource blocks (RBs), and CRSs are mapped in units of resource elements (REs), so there is a limit. The present invention relates to this.

The disclosed embodiment is intended to provide an apparatus and method for effectively providing a service.

The present invention for solving the above problems is a method of a terminal in a wireless communication system, the method comprising: receiving cell specific reference signal (CRS) pattern related configuration information from a base station; Receiving a physical downlink shared channel (PDSCH) from the base station; and performing interference cancellation on the PDSCH based on the CRS pattern related configuration information.

According to the disclosed embodiment, it is possible to effectively provide a service in a wireless communication system in which NR and LTE networks coexist.

1 is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a 5G system.
2 is a diagram illustrating an example of a slot structure considered in a 5G system.
3 is a diagram illustrating an example of setting a bandwidth portion in a 5G communication system.
4 is a diagram illustrating an example of a control resource set (CORESET) through which a downlink control channel is transmitted in a 5G wireless communication system.
5 is a diagram illustrating an example of a basic unit of time and frequency resources constituting a downlink control channel that can be used in 5G.
6 is a diagram for describing a method for a base station and a terminal to transmit and receive data in consideration of a downlink data channel and a rate matching resource.
7A is a diagram for explaining an example of an operation of a base station in a wireless communication system according to various embodiments of the present disclosure;
7B is a diagram for explaining an example of an operation of a terminal in a wireless communication system according to various embodiments of the present disclosure;
8 is a diagram for explaining an example of an operation of a terminal in a wireless communication system according to various embodiments of the present disclosure;
9A is a diagram for explaining an example of an operation of a base station in a wireless communication system according to various embodiments of the present disclosure;
9B is a diagram for explaining an example of an operation of a terminal in a wireless communication system according to various embodiments of the present disclosure;
10A is a diagram for explaining an example of an operation of a terminal in a wireless communication system according to various embodiments of the present disclosure;
10B is a diagram for explaining an example of an operation of a terminal in a wireless communication system according to various embodiments of the present disclosure;
11 is a diagram for explaining an example of an operation of a terminal in a wireless communication system according to various embodiments of the present disclosure;
12 is a block diagram of a terminal according to an embodiment of the present invention.
13 is a block diagram of a base station according to an embodiment of the present invention.

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

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

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present disclosure, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the disclosure of the present disclosure to be complete, and common knowledge in the technical field to which the present disclosure belongs It is provided to fully inform those who have the scope of the disclosure, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout. In addition, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration may unnecessarily obscure the subject matter of the present disclosure, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in the present disclosure, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

Hereinafter, the base station, as a subject performing resource allocation of the terminal, may be at least one of gNode B, eNode B, Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, a downlink (DL) is a wireless transmission path of a signal transmitted from a base station to a terminal, and an uplink (UL) is a wireless transmission path of a signal transmitted from a terminal to a flag station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiment of the present disclosure may be applied to other communication systems having a similar technical background or channel type. For example, 5G mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in this, and 5G below may be a concept including existing LTE, LTE-A and other similar services. have. In addition, the present disclosure may be applied to other communication systems through some modifications within a range that does not significantly depart from the scope of the present disclosure as judged by a person having skilled technical knowledge.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible that the instructions stored in the flow chart block(s) produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in blocks to occur out of order. For example, two blocks shown one after another may in fact be performed substantially simultaneously, or it is possible that the blocks are sometimes performed in the reverse order according to the corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and '~ unit' performs certain roles do. However, '-part' is not limited to software or hardware. '~' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Accordingly, as an example, '~' indicates components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card. Also, in an embodiment, '~ unit' may include one or more processors.

A wireless communication system, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2 HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE 802.16e, such as communication standards such as broadband wireless broadband wireless providing high-speed, high-quality packet data service It is evolving into a communication system.

As a representative example of the broadband wireless communication system, in the LTE system, an Orthogonal Frequency Division Multiplexing (OFDM) scheme is employed in a Downlink (DL), and Single Carrier Frequency Division Multiple (SC-FDMA) is used in an Uplink (UL). Access) method is adopted. Uplink refers to a radio link in which a UE (User Equipment) or MS (Mobile Station) transmits data or control signals to a base station (eNode B, or base station (BS)). It means a wireless link that transmits data or control signals. In the multiple access method as described above, the data or control information of each user can be divided by allocating and operating the time-frequency resources to which the data or control information is to be transmitted for each user so that they do not overlap each other, that is, orthogonality is established. can

As a future communication system after LTE, that is, the 5G communication system must be able to freely reflect various requirements of users and service providers, so services that simultaneously satisfy various requirements must be supported. Services considered for the 5G communication system include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), Ultra Reliability Low Latency Communication (URLLC), etc. There is this.

eMBB aims to provide more improved data transfer rates than the data transfer rates supported by existing LTE, LTE-A or LTE-Pro. For example, in the 5G communication system, the eMBB must be able to provide a maximum data rate of 20 Gbps in the downlink and a maximum data rate of 10 Gbps in the uplink from the viewpoint of one base station. In addition, the 5G communication system must provide the maximum transmission speed and, at the same time, provide the increased user perceived data rate of the terminal. In order to satisfy such a requirement, it is required to improve various transmission/reception technologies, including a more advanced multi-antenna (Multi Input Multi Output, MIMO) transmission technology. In addition, while transmitting signals using up to 20 MHz transmission bandwidth in the 2 GHz band used by LTE, the 5G communication system uses a frequency bandwidth wider than 20 MHz in the frequency band of 3 to 6 GHz or 6 GHz or more. The transmission speed can be satisfied.

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in the 5G communication system. In order to efficiently provide the Internet of Things, mMTC requires large-scale terminal access support within a cell, improved terminal coverage, improved battery life, and reduced terminal cost. Since the Internet of Things is attached to various sensors and various devices to provide communication functions, it must be able to support a large number of terminals (eg, 1,000,000 terminals/km2) within a cell. In addition, since a terminal supporting mMTC is highly likely to be located in a shaded area that a cell cannot cover, such as the basement of a building, due to the nature of the service, it may require wider coverage compared to other services provided by the 5G communication system. A terminal supporting mMTC must be composed of a low-cost terminal, and since it is difficult to frequently exchange the battery of the terminal, a very long battery life time such as 10 to 15 years may be required.

Finally, in the case of URLLC, it is a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, remote control of a robot or machine, industrial automation, Unmaned Aerial Vehicle, remote health care, emergency situation A service used for an emergency alert, etc. may be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and at the same time have a requirement of a packet error rate of 10 ^-5 or less. Therefore, for a service that supports URLLC, the 5G system must provide a smaller Transmit Time Interval (TTI) than other services, and at the same time, it is designed to allocate wide resources in the frequency band to secure the reliability of the communication link. items may be required.

The three services of 5G, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. In this case, in order to satisfy different requirements of each service, different transmission/reception techniques and transmission/reception parameters may be used between services. Of course, 5G is not limited to the three services described above.

Hereinafter, the frame structure of the 5G system will be described in more detail with reference to the drawings.

1 is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a 5G system.

(일례로 12)개의 연속된 RE들은 하나의 자원 블록(Resource Block, RB, 104)을 구성할 수 있다. 1 , the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. In the time and frequency domain, the basic unit of resources is a resource element (RE, 101), defined as 1 OFDM (Orthogonal Frequency Division Multiplexing) symbol 102 on the time axis and 1 subcarrier 103 on the frequency axis. can be in the frequency domain

(for example, 12) consecutive REs may constitute one resource block (Resource Block, RB, 104).

2 is a diagram illustrating an example of a slot structure considered in a 5G system.

)=14). 1 서브프레임(201)은 하나 또는 복수 개의 슬롯(202, 203)으로 구성될 수 있으며, 1 서브프레임(201)당 슬롯(202, 203)의 개수는 부반송파 간격에 대한 설정 값 μ(204, 205)에 따라 다를 수 있다. 도 2의 일 예에서는 부반송파 간격 설정 값으로 μ=0(204)인 경우와 μ=1(205)인 경우가 도시되어 있다. μ=0(204)일 경우, 1 서브프레임(201)은 1개의 슬롯(202)으로 구성될 수 있고, μ=1(205)일 경우, 1 서브프레임(201)은 2개의 슬롯(203)으로 구성될 수 있다. 즉 부반송파 간격에 대한 설정 값 μ에 따라 1 서브프레임 당 슬롯 수(

)가 달라질 수 있고, 이에 따라 1 프레임 당 슬롯 수(

)가 달라질 수 있다. 각 부반송파 간격 설정 μ에 따른

및

는 하기의 표 1로 정의될 수 있다.2 shows an example of a structure of a frame 200 , a subframe 201 , and a slot 202 . One frame 200 may be defined as 10 ms. One subframe 201 may be defined as 1 ms, and thus one frame 200 may be composed of a total of 10 subframes 201 . One slot (202, 203) may be defined as 14 OFDM symbols (that is, the number of symbols per slot (

)=14). One subframe 201 may consist of one or a plurality of slots 202 and 203, and the number of slots 202 and 203 per one subframe 201 is a set value μ(204, 205) for the subcarrier interval. ) may vary depending on In the example of FIG. 2 , a case of μ=0 (204) and a case of μ=1 (205) are illustrated as subcarrier spacing setting values. When μ=0 (204), one subframe 201 may consist of one slot 202, and when μ=1 (205), one subframe 201 may consist of two slots 203. can be composed of That is, the number of slots per subframe (

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

) may be different. According to each subcarrier spacing setting μ

and

may be defined in Table 1 below.

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

Next, a bandwidth part (BWP) setting in the 5G communication system will be described in detail with reference to FIG. 3 .

3 is a diagram illustrating an example of setting a bandwidth portion in a 5G communication system.

3 shows an example in which the UE bandwidth 300 is set to two bandwidth parts, that is, a bandwidth part #1 (BWP#1) 301 and a bandwidth part #2 (BWP#2) 302. has been The base station may set one or a plurality of bandwidth portions to the terminal, and may set the following information for each bandwidth portion.

Of course, it is not limited to the above example, and in addition to the configuration information, various parameters related to the bandwidth portion may be configured in the terminal. The information may be transmitted from the base station to the terminal through higher layer signaling, for example, RRC (Radio Resource Control) signaling. At least one bandwidth portion among the set one or a plurality of bandwidth portions may be activated. Whether to activate the set bandwidth portion may be semi-statically transmitted from the base station to the terminal through RRC signaling or may be dynamically transmitted through downlink control information (DCI).

According to some embodiments, the terminal before the RRC (Radio Resource Control) connection may receive an initial bandwidth portion (Initial BWP) for the initial connection from the base station through the MIB (Master Information Block). More specifically, in the terminal, the PDCCH for receiving the system information (Remaining System Information; RMSI or System Information Block 1; may correspond to SIB1) required for initial access through the MIB in the initial access step can be transmitted. Setting information for a control resource set (CORESET) and a search space may be received. The control resource set and the search space set by the MIB may be regarded as identifier (Identity, ID) 0, respectively. The base station may notify the terminal of configuration information such as frequency allocation information, time allocation information, and Numerology for the control resource set #0 through the MIB. In addition, the base station may notify the terminal through the MIB of configuration information on the monitoring period and occasion for the control resource set #0, that is, configuration information on the search space #0. The UE may regard the frequency domain set as the control resource set #0 obtained from the MIB as an initial bandwidth portion for initial access. In this case, the identifier (ID) of the initial bandwidth portion may be regarded as 0.

The configuration of the bandwidth part supported by the 5G may be used for various purposes.

According to some embodiments, when the bandwidth supported by the terminal is smaller than the system bandwidth, this may be supported by setting the bandwidth part. For example, when the base station sets the frequency position (setting information 2) of the bandwidth part to the terminal, the terminal can transmit/receive data at a specific frequency location within the system bandwidth.

Also, according to some embodiments, the base station may set a plurality of bandwidth portions to the terminal for the purpose of supporting different numerologies. For example, in order to support both data transmission and reception using a subcarrier interval of 15 kHz and a subcarrier interval of 30 kHz to a certain terminal, two bandwidth portions may be set to a subcarrier interval of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be subjected to frequency division multiplexing, and when data is transmitted/received at a specific subcarrier interval, a bandwidth portion set for the corresponding subcarrier interval may be activated.

Also, according to some embodiments, for the purpose of reducing power consumption of the terminal, the base station may set a bandwidth portion having a bandwidth of a different size to the terminal. For example, when the terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz and always transmits and receives data using the corresponding bandwidth, very large power consumption may occur. In particular, monitoring an unnecessary downlink control channel with a large bandwidth of 100 MHz in a situation in which there is no traffic may be very inefficient in terms of power consumption. For the purpose of reducing power consumption of the terminal, the base station may set a bandwidth portion of a relatively small bandwidth to the terminal, for example, a bandwidth portion of 20 MHz. In a situation where there is no traffic, the terminal may perform a monitoring operation in the 20 MHz bandwidth portion, and when data is generated, it may transmit/receive data in the 100 MHz bandwidth portion according to the instruction of the base station.

In the method of setting the bandwidth part, terminals before RRC connection (Connected) may receive configuration information for the initial bandwidth part (Initial Bandwidth Part) through the MIB (Master Information Block) in the initial access stage. More specifically, the UE is a control resource set for a downlink control channel through which Downlink Control Information (DCI) for scheduling a System Information Block (SIB) can be transmitted from the MIB of a Physical Broadcast Channel (PBCH). , CORESET) can be set. The bandwidth of the control resource set set as the MIB may be regarded as an initial bandwidth portion, and the UE may receive a Physical Downlink Shared Channel (PDSCH) through which the SIB is transmitted through the configured initial bandwidth portion. In addition to the purpose of receiving the SIB, the initial bandwidth portion may be utilized for other system information (OSI), paging, and random access.

Next, an SS (Synchronization Signal)/PBCH block in 5G will be described.

The SS/PBCH block may mean a physical layer channel block composed of a primary SS (PSS), a secondary SS (SSS), and a PBCH. Specifically, it is as follows.

- PSS: A signal that serves as a reference for downlink time/frequency synchronization and provides some information on cell ID.

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

- PBCH: Provides essential system information necessary for transmitting and receiving data channel and control channel of the terminal. The essential system information may include search space-related control information indicating radio resource mapping information of a control channel, scheduling control information on a separate data channel for transmitting system information, and the like.

- SS/PBCH block: The SS/PBCH block consists of a combination of PSS, SSS, and PBCH. One or a plurality of SS/PBCH blocks may be transmitted within 5 ms, and each transmitted SS/PBCH block may be distinguished by an index.

The UE may detect the PSS and SSS in the initial access stage and may decode the PBCH. The UE may obtain the MIB from the PBCH, and may receive a control resource set (CORESET) #0 (which may correspond to a control resource set having a control resource set index of 0) set therefrom. The UE may perform monitoring on the control resource set #0, assuming that the selected SS/PBCH block and a demodulation reference signal (DMRS) transmitted from the control resource set #0 are QCL (Quasi Co Location). The terminal may receive system information as downlink control information transmitted from the control resource set #0. The UE may obtain RACH (Random Access Channel) related configuration information required for initial access from the received system information. The UE may transmit a physical RACH (PRACH) to the base station in consideration of the selected SS/PBCH index, and the base station receiving the PRACH may obtain information on the SS/PBCH block index selected by the UE. The base station can check which block the terminal selects from each of the SS/PBCH blocks, and can know the fact that the control resource set #0 associated with the selected block is monitored.

Next, downlink control information (DCI) in the 5G system will be described in detail.

In the 5G system, scheduling information for uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink data channel (Physical Downlink Shared Channel, PDSCH)) is through DCI It may be transmitted from the base station to the terminal. The UE may monitor the DCI format for fallback and the DCI format for non-fallback for PUSCH or PDSCH. The DCI format for countermeasures may be composed of a fixed field predetermined between the base station and the terminal, and the DCI format for non-prevention may include a configurable field.

DCI may be transmitted through a Physical Downlink Control Channel (PDCCH), which is a physical downlink control channel, through a channel coding and modulation process. A cyclic redundancy check (CRC) is attached to the DCI message payload, and the CRC may be scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the UE. Different RNTIs may be used according to the purpose of the DCI message, for example, UE-specific data transmission, a power control command, or a random access response. That is, the RNTI is not explicitly transmitted, but is transmitted while being included in the CRC calculation process. Upon receiving the DCI message transmitted on the PDCCH, the UE checks the CRC using the assigned RNTI. If the CRC check result is correct, the UE can know that the message has been transmitted to the UE.

For example, DCI scheduling PDSCH for system information (SI) may be scrambled with SI-RNTI. DCI scheduling a PDSCH for a random access response (RAR) message may be scrambled with an RA-RNTI. DCI scheduling a PDSCH for a paging message may be scrambled with a P-RNTI. DCI notifying SFI (Slot Format Indicator) may be scrambled with SFI-RNTI. DCI notifying Transmit Power Control (TPC) may be scrambled with TPC-RNTI. DCI for scheduling UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

DCI format 0_0 may be used as a DCI for scheduling PUSCH, and in this case, CRC may be scrambled with C-RNTI. DCI format 0_0 in which CRC is scrambled with C-RNTI may include, for example, the following information.

DCI format 0_1 may be used as non-preparation DCI for scheduling PUSCH, and in this case, CRC may be scrambled with C-RNTI. DCI format 0_1 in which CRC is scrambled with C-RNTI may include, for example, the following information.

DCI format 1_0 may be used as a DCI for scheduling PDSCH, and in this case, CRC may be scrambled with C-RNTI. DCI format 1_0 in which CRC is scrambled with C-RNTI may include, for example, the following information.

DCI format 1_1 may be used as non-preparation DCI for scheduling PDSCH, and in this case, CRC may be scrambled with C-RNTI. DCI format 1_1 in which CRC is scrambled with C-RNTI may include, for example, the following information.

Hereinafter, a method of allocating time domain resources for a data channel in a 5G communication system will be described.

The base station provides a table for time domain resource allocation information for a downlink data channel (Physical Downlink Shared Channel; PDSCH) and an uplink data channel (Physical Uplink Shared Channel; PUSCH) to the UE higher layer signaling (e.g., RRC signaling). The base station may set a table consisting of a maximum of maxNrofDL-Allocations = 16 entries for the PDSCH, and may set a table consisting of a maximum of maxNrofUL-Allocations = 16 entries for the PUSCH. The time domain resource allocation information includes, for example, the PDCCH-to-PDSCH slot timing (corresponding to the time interval in slot units between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted by K0) or PDCCH-to-PUSCH slot timing (corresponding to the time interval in slot units between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted by K2), the PDSCH or PUSCH is scheduled in the slot Information on the position and length of the start symbol, a mapping type of PDSCH or PUSCH, etc. may be included. For example, information such as the table below may be notified from the base station to the terminal.

The base station may notify the terminal of one of the entries in the table for the time domain resource allocation information through L1 signaling (eg, DCI) (eg, the 'time domain resource allocation' field in DCI may indicate ). The terminal may acquire time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

Hereinafter, a method of allocating a frequency domain resource for a data channel in a 5G communication system will be described.

In 5G, there are two types, resource allocation type 0 and resource allocation type, as a method of indicating frequency domain resource allocation information for a downlink data channel (Physical Downlink Shared Channel; PDSCH) and an uplink data channel (Physical Uplink Shared Channel; PUSCH). 1 is supported.

resource allocation type 0

- RB allocation information may be notified from the base station to the terminal in the form of a bitmap for a resource block group (RBG). At this time, the RBG may be composed of a set of consecutive VRBs (Virtual RBs), and the size P of the RBG is based on a value set by a higher layer parameter ( rbg-Size ) and the size value of the bandwidth part defined in the table below. can be determined by

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

Nominal RBG size P

인 대역폭 파트 i의 총 RBG의 수 (

)는 하기와 같이 정의될 수 있다.- size

Total number of RBGs in bandwidth part i (

) may be defined as follows.

비트 크기의 비트맵의 각 비트들은 각각의 RBG에 대응될 수 있다. RBG들은 대역폭파트의 가장 낮은 주파수 위치에서 시작하여 주파수가 증가하는 순서대로 인덱스가 부여될 수 있다. 대역폭파트 내의

개의 RBG들에 대하여, RBG#0에서부터 RBG#(

)이 RBG 비트맵의 MSB에서부터 LSB로 매핑될 수 있다. 단말은 비트맵 내의 특정 비트 값이 1일 경우, 해당 비트 값에 대응되는 RBG가 할당되었다고 판단할 수 있고, 비트맵 내의 특정 비트 값이 0일 경우, 해당 비트 값에 대응되는 RBG가 할당되지 않았다고 판단할 수 있다.-

Each bit of the bit-sized bitmap may correspond to each RBG. RBGs may be assigned an index in the order of increasing frequency, starting from the lowest frequency position of the bandwidth part. within the bandwidth

For RBGs, from RBG#0 to RBG#(

) may be mapped from the MSB to the LSB of the RBG bitmap. When a specific bit value in the bitmap is 1, the UE can determine that the RBG corresponding to the bit value is allocated, and when the specific bit value in the bitmap is 0, the RBG corresponding to the bit value is not allocated. can judge

Resource Allocation Type 1

)과 연속적으로 할당된 RB의 길이 (

)로 구성될 수 있다. 보다 구체적으로,

크기의 대역폭파트 내의 RIV는 하기와 같이 정의될 수 있다.- RB allocation information may be notified from the base station to the terminal as information on the start position and length of the continuously allocated VRBs. In this case, interleaving or non-interleaving may be additionally applied to the continuously allocated VRBs. The resource allocation field of resource allocation type 1 may consist of a Resource Indication Value (RIV), and the RIV is the starting point (

) and the length of consecutively allocated RBs (

) can be composed of More specifically,

The RIV in the bandwidth part of the size may be defined as follows.

Hereinafter, a downlink control channel in a 5G communication system will be described in more detail with reference to the drawings.

4 is a diagram illustrating an example of a control resource set (CORESET) through which a downlink control channel is transmitted in a 5G wireless communication system. Figure 4 shows two control resource sets (control resource set #1 (401), control resource set #2 (402) in one slot 420 on the time axis and the UE bandwidth part 410 on the frequency axis. )) is a diagram showing an example in which is set. The control resource sets 401 and 402 may be set in a specific frequency resource 403 within the entire terminal bandwidth portion 410 on the frequency axis. As a time axis, one or a plurality of OFDM symbols may be set, and this may be defined as a Control Resource Set Duration (404). Referring to the example shown in FIG. 4 , the control resource set #1 401 may be set to a control resource set length of 2 symbols, and the control resource set #2 402 may be set to a control resource set length of 1 symbol. can be

The aforementioned set of control resources in 5G may be set by the base station to the terminal through higher layer signaling (eg, system information, master information block (MIB), radio resource control (RRC) signaling). Setting the control resource set to the terminal means providing information such as a control resource set identifier (Identity), a frequency position of the control resource set, and a symbol length of the control resource set. For example, information provided to set the control resource set is as follows.

In Table 10, tci-StatesPDCCH (simply referred to as Transmission Configuration Indication (TCI) state) configuration information is one or a plurality of SS (Synchronization Signals) in a Quasi Co Located (QCL) relationship with DMRS transmitted from a corresponding control resource set. )/Physical Broadcast Channel (PBCH) block (Block) index or CSI-RS (Channel State Information Reference Signal) index information.

5 is a diagram illustrating an example of a basic unit of time and frequency resources constituting a downlink control channel that can be used in 5G. According to FIG. 5, a basic unit of time and frequency resources constituting a control channel may be referred to as a resource element group (REG) 503, and the REG 503 has 1 OFDM symbol 501 on the time axis and 1 PRB on the frequency axis. (Physical Resource Block, 502), that is, it may be defined as 12 subcarriers. The base station may configure a downlink control channel allocation unit by concatenating the REG 503 .

As shown in FIG. 5 , when a basic unit to which a downlink control channel is allocated in 5G is referred to as a control channel element (CCE) 504 , one CCE 504 may include a plurality of REGs 503 . If the REG 503 shown in FIG. 5 is described as an example, the REG 503 may be composed of 12 REs, and if 1 CCE 504 is composed of 6 REGs 503 , then 1 CCE 504 is composed of 6 REGs 503 . ) may consist of 72 REs. When the downlink control resource set is set, the corresponding area may be composed of a plurality of CCEs 504, and a specific downlink control channel may have one or a plurality of CCEs 504 according to an aggregation level (AL) in the control resource set. ) can be mapped and transmitted. The CCEs 504 in the control resource set are divided by numbers, and in this case, the numbers of the CCEs 504 may be assigned according to a logical mapping scheme.

The basic unit of the downlink control channel shown in FIG. 5 , that is, the REG 503 , may include both REs to which DCI is mapped and a region to which the DMRS 505 , which is a reference signal for decoding them, is mapped. As in FIG. 5 , three DMRSs 505 may be transmitted within one REG 503 . The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 according to an aggregation level (AL), and the number of different CCEs is the link adaptation of the downlink control channel. can be used to implement For example, when AL=L, one downlink control channel may be transmitted through L CCEs. The UE needs to detect a signal without knowing information about the downlink control channel. For blind decoding, a search space indicating a set of CCEs is defined. The search space is a set of downlink control channel candidates consisting of CCEs that the UE should attempt to decode on a given aggregation level, and various aggregations that make one bundle with 1, 2, 4, 8, or 16 CCEs. Since there is a level, the terminal may have a plurality of search spaces. A search space set may be defined as a set of search spaces in all set aggregation levels.

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

In 5G, the parameter for the search space for the PDCCH may be set from the base station to the terminal through higher layer signaling (eg, SIB, MIB, RRC signaling). For example, the base station is the number of PDCCH candidates in each aggregation level L, the monitoring period for the search space, the monitoring occasion in symbol units in the slot for the search space, the search space type (common search space or terminal-specific search space), A combination of a DCI format and an RNTI to be monitored in the corresponding search space, a control resource set index for monitoring the search space, etc. may be set to the UE. For example, the parameter for the search space for the PDCCH may include the following information.

According to the configuration information, the base station may set one or a plurality of search space sets to the terminal. According to some embodiments, the base station may set the search space set 1 and the search space set 2 to the terminal. In search space set 1, the UE may be configured to monitor DCI format A scrambled with X-RNTI in the common search space, and in search space set 2, the UE uses DCI format B scrambled with Y-RNTI in the UE-specific search space. It can be set to monitor in

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

In the common search space, a combination of the following DCI format and RNTI may be monitored. Of course, it is not limited to the following examples.

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

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

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

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

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

In the UE-specific search space, a combination of the following DCI format and RNTI may be monitored. Of course, it is not limited to the following examples.

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

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

The specified RNTIs may follow the definitions and uses below.

C-RNTI (Cell RNTI): UE-specific PDSCH scheduling purpose

TC-RNTI (Temporary Cell RNTI): UE-specific PDSCH scheduling purpose

CS-RNTI (Configured Scheduling RNTI): Semi-statically configured UE-specific PDSCH scheduling purpose

RA-RNTI (Random Access RNTI): Used for scheduling PDSCH in the random access phase

P-RNTI (Paging RNTI): PDSCH scheduling purpose for which paging is transmitted

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

INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH is pucturing

TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Purpose of indicating power control command for PUSCH

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

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

The above specified DCI formats may follow the definition below.

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

In 5G, the search space of the aggregation level L in the control resource set p and the search space set s may be expressed as the following equation.

[Equation 1]

- L: Aggregation level

- n _CI : carrier (Carrier) index

- N _CCE,p : The total number of CCEs present in the control resource set p

- n ^μ _s,f : slot index

- M ^(L) _{p, s, max} : the number of PDCCH candidates of aggregation level L

-m _snCI = 0, ..., M ^(L) _p,s,max -1: PDCCH candidate index of aggregation level L

- i = 0, ..., L-1

-

- n _RNTI : terminal identifier

The Y_(p,n ^μ _s,f ) value may correspond to 0 in the case of a common search space.

The Y_(p,n ^μ _s,f ) value may correspond to a value that changes depending on the terminal's identity (C-RNTI or ID set for the terminal by the base station) and the time index in the terminal-specific search space.

In 5G, as a plurality of search space sets can be set with different parameters (eg, parameters in Table 10), the set of search space sets monitored by the UE at every time point may vary. For example, if the search space set #1 is set as the X-slot period, the search space set #2 is set as the Y-slot period, and X and Y are different, the UE searches with the search space set #1 in a specific slot. All of the space set #2 can be monitored, and one of the search space set #1 and the search space set #2 can be monitored in a specific slot.

When a plurality of search space sets are configured for the terminal, the following conditions may be considered in a method for determining the search space set to be monitored by the terminal.

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

The number of PDCCH candidates that can be monitored per slot does not exceed M ^μ . M ^μ may be defined as the maximum number of PDCCH candidates per slot in a cell set to a subcarrier interval of 15·2 ^μ kHz, and may be defined in the table below.

Maximum number of PDCCH candidates per slot and per serving cell (M ^μ ) 0 44 One 36 2 22 3 20

[Condition 2: Limit the maximum number of CCEs]

The number of CCEs constituting the entire search space per slot (here, the total search space means the entire set of CCEs corresponding to the union region of a plurality of search space sets) does not exceed C ^μ . C ^μ may be defined as the maximum number of CCEs per slot in a cell set to a subcarrier interval of 15·2 ^μ kHz, and may be defined in the table below.

Maximum number of CCEs per slot and per serving cell (C ^μ ) 0 56 One 56 2 48 3 32

For convenience of explanation, a situation in which both conditions 1 and 2 are satisfied at a specific time point is defined as “condition A”. Therefore, not satisfying condition A may mean not satisfying at least one of conditions 1 and 2 above.

Depending on the setting of the search space sets of the base station, the condition A may not be satisfied at a specific time point. If condition A is not satisfied at a specific time point, the UE may select and monitor only some of the search space sets configured to satisfy condition A at the corresponding time point, and the base station may transmit the PDCCH to the selected search space set.

The following method may be followed as a method of selecting a partial search space from among the entire set of search spaces.

If condition A for PDCCH is not satisfied at a specific time point (slot),

The terminal (or the base station) may preferentially select a search space set in which the search space type is set as a common search space from among search space sets existing at a corresponding time, over a search space set set as a terminal-specific search space.

When all search space sets set as the common search space are selected (that is, condition A is satisfied even after all search spaces set as the common search space are selected), the terminal (or the base station) uses the terminal-specific search space You can select search space sets set to . In this case, when there are a plurality of search space sets set as the terminal-specific search space, a search space set having a low search space set index may have a higher priority. The terminal (or the base station) may select the terminal-specific search space sets within a range in which condition A is satisfied in consideration of priority.

In 5G, the control resource set set may be composed of N _RB ^CORESET RBs in the frequency domain, and may be composed of N _symb ^CORESET ∈{1,2,3} symbols in the time axis. One CCE may consist of 6 REGs, and a REG may be defined as 1 RB for 1 OFDM symbol. In one control resource set, REGs may be indexed in a time-first order, starting with REG index 0 from the first OFDM symbol of the control resource set, the lowest RB.

In 5G, an interleaved method and a non-interleaved method are supported as a transmission method for the PDCCH. The base station may set whether to transmit interleaving or non-interleaving for each control resource set to the terminal through higher layer signaling. Interleaving may be performed in units of REG bundles. A REG bundle may be defined as a set of one or a plurality of REGs. The UE may determine the CCE-to-REG mapping method in the corresponding control resource set in the following manner based on whether interleaving or non-interleaving transmission configured from the base station is performed.

Hereinafter, a rate matching operation and a puncturing operation will be described in detail.

When the time and frequency resource A to transmit the arbitrary symbol sequence A overlaps the arbitrary time and frequency resource B, rate matching or puncturing is performed with the transmission/reception operation of the channel A considering the resource C of the region where the resource A and the resource B overlap. action may be considered. A specific operation may follow the following contents.

Rate Matching Behavior

- The base station may map and transmit the channel A only for the remaining resource regions except for the resource C corresponding to the region overlapping the resource B among all the resources A for transmitting the symbol sequence A to the terminal. For example, symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol 4}, resource A is {resource #1, resource #2, resource #3, resource #4}, When B is {resource #3, resource #5}, the base station places a symbol sequence on {resource #1, resource #2, resource #4}, which are the remaining resources except for {resource #3} corresponding to resource C from among resource A It can be sent by mapping A sequentially. As a result, the base station may map the symbol sequence {symbol #1, symbol #2, symbol #3} to {resource #1, resource #2, resource #4}, respectively, and transmit it.

The UE may determine the resource A and the resource B from the scheduling information for the symbol sequence A from the base station, and through this, may determine the resource C, which is an area where the resource A and the resource B overlap. The UE may receive the symbol sequence A, assuming that the symbol sequence A is mapped and transmitted in the remaining region except for the resource C among all the resources A. For example, symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol 4}, resource A is {resource #1, resource #2, resource #3, resource #4}, When B is {resource #3, resource #5}, the terminal places a symbol sequence on {resource #1, resource #2, resource #4}, which are the remaining resources except for {resource #3} corresponding to resource C among resource A Assuming that A is mapped sequentially, it can be received. As a result, the terminal assumes that the symbol sequence {symbol #1, symbol #2, symbol #3} is mapped to {resource #1, resource #2, resource #4} and transmitted, respectively, and performs a subsequent series of reception operations. can

Puncturing operation

The base station maps the symbol sequence A to the entire resource A when there is a resource C corresponding to the region overlapping the resource B among all the resources A to which the symbol sequence A is to be transmitted to the terminal, but transmission is performed in the resource region corresponding to the resource C. It is not performed, and transmission may be performed only for the remaining resource regions except for resource C among resource A. For example, symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol 4}, resource A is {resource #1, resource #2, resource #3, resource #4}, When B is {resource #3, resource #5}, the base station converts the symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} to resource A {resource #1, resource #2, resource # 3, resource #4} can be mapped respectively, and the symbol sequence corresponding to {resource#1, resource#2, resource#4}, which is the remaining resources except for {resource#3} corresponding to resource C, among resource A. Only symbol #1, symbol #2, and symbol #4} may be transmitted, and {symbol #3} mapped to {resource #3} corresponding to resource C may not be transmitted. As a result, the base station can map the symbol sequence {symbol #1, symbol #2, symbol #4} to {resource #1, resource #2, resource #4}, respectively, and transmit it.-

The UE may determine the resource A and the resource B from the scheduling information for the symbol sequence A from the base station, and through this, may determine the resource C, which is an area where the resource A and the resource B overlap. The UE may receive the symbol sequence A, assuming that the symbol sequence A is mapped to the entire resource A and transmitted only in the remaining regions except for the resource C in the resource region A. For example, symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol 4}, resource A is {resource #1, resource #2, resource #3, resource #4}, If B is {resource #3, resource #5}, the terminal indicates that the symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} is resource A {resource #1, resource #2, resource # It can be assumed that each is mapped to 3 and resource #4}, but {symbol #3} mapped to {resource #3} corresponding to resource C is not transmitted, and {resource #3 corresponding to resource C among resources A }, a symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to {resource #1, resource #2, resource #4}, which is the remaining resources, may be assumed to be mapped and transmitted. As a result, the terminal assumes that the symbol sequence {symbol #1, symbol #2, symbol #4} is mapped to {resource #1, resource #2, resource #4} and transmitted, respectively, and performs a subsequent series of reception operations. can

Hereinafter, a method of setting a rate matching resource for the purpose of rate matching in a 5G communication system will be described. Rate matching means that the size of the signal is adjusted in consideration of the amount of resources capable of transmitting the signal. For example, rate matching of a data channel may mean that a data size is adjusted accordingly without mapping and transmitting a data channel for a specific time and frequency resource region.

6 is a diagram for describing a method for a base station and a terminal to transmit and receive data in consideration of a downlink data channel and a rate matching resource.

6 shows a downlink data channel (PDSCH) 601 and a rate matching resource 602 . The base station may configure one or more rate matching resources 602 through higher layer signaling (eg, RRC signaling) to the terminal. The rate matching resource 602 configuration information may include time axis resource allocation information 603 , frequency axis resource allocation information 604 , and period information 605 . In the following description, the bitmap corresponding to the frequency-axis resource allocation information 604 corresponds to a “first bitmap”, the bitmap corresponding to the time-axis resource allocation information 603 corresponds to the “second bitmap”, and the period information 605 corresponds to the The bitmap to be used is called "third bitmap". When all or part of the time and frequency resources of the scheduled data channel 601 overlap with the set rate matching resource 602, the base station rate-matches the data channel 601 in the rate matching resource 602 part and transmits it , the terminal may perform reception and decoding after assuming that the data channel 601 is rate matched in the rate matching resource 602 part.

The base station can dynamically notify the terminal through DCI whether to rate-match the data channel in the set rate matching resource part through additional configuration (corresponds to the "rate matching indicator" in the DCI format described above) . Specifically, the base station may select some of the set rate matching resources and group them into a rate matching resource group, and determine whether the data channel for each rate matching resource group has rate matching using a bitmap method to the terminal by DCI. can direct For example, if four rate matching resources, RMR#1, RMR#2, RMR#3, and RMR#4 are set, the base station as a rate matching group RMG#1={RMR#1, RMR#2}, RMG# 2 = {RMR#3, RMR#4} can be set, and by using 2 bits in the DCI field, it is possible to indicate to the UE whether the rate is matched in RMG#1 and RMG#2, respectively, with a bitmap. For example, "1" may be indicated when rate matching is to be performed, and "0" may be indicated when rate matching is not to be performed.

5G supports the granularity of "RB symbol level" and "RE level" as a method of setting the above-described rate matching resource in the terminal. More specifically, the following setting method may be followed.

RB symbol level

The terminal may receive up to four RateMatchPattern for each bandwidth part as upper layer signaling, and one RateMatchPattern may include the following.

- As a reserved resource in the bandwidth part, a resource in which time and frequency resource regions of the corresponding reserved resource are set may be included in a combination of a bitmap of an RB level and a bitmap of a symbol level on the frequency axis. The reserved resource may span one or two slots. A time domain pattern (periodicityAndPattern) in which the time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may be additionally set.

- A time and frequency domain resource region set as a control resource set in the bandwidth part and a resource region corresponding to a time domain pattern set as a search space setting in which the resource region is repeated may be included.

RE level

The UE may receive the following contents configured through higher layer signaling.

- The number of ports (nrofCRS-Ports) and LTE-CRS-vshift(s) of LTE CRS as configuration information (lte-CRS-ToMatchAround) for RE corresponding to the LTE CRS (Cell-specific Reference Signal or Common Reference Signal) pattern (v-shift), the center subcarrier location information (carrierFreqDL) of the LTE carrier from the reference frequency point (eg reference point A), the bandwidth size of the LTE carrier (carrierBandwidthDL) information, MBSFN (Multicast-broadcast single -frequency network) may include subframe configuration information (mbsfn-SubframConfigList) and the like. The UE may determine the location of the CRS in the NR slot corresponding to the LTE subframe based on the above-described information.

- Configuration information for a resource set corresponding to one or more ZP (Zero Power) CSI-RSs in the bandwidth part may be included.

Next, the rate match process for the above-described LTE CRS will be described in detail. For the coexistence of LTE (Long Term Evolution) and NR (New RAT) (LTE-NR Coexistence), NR provides a function for setting a CRS (Cell Specific Reference Signal) pattern of LTE to an NR terminal. More specifically, the CRS pattern may be provided by RRC signaling including at least one parameter in ServingCellConfig IE (Information Element) or ServingCellConfigCommon IE. Examples of the parameter may include lte-CRS-ToMatchAround, lte-CRS-PatternList1-r16, lte-CRS-PatternList2-r16, crs-RateMatch-PerCORESETPoolIndex-r16, and the like.

Rel-15 NR provides a function in which one CRS pattern can be set per serving cell through the lte-CRS-ToMatchAround parameter. In Rel-16 NR, the above function has been extended to enable setting of a plurality of CRS patterns per serving cell. More specifically, a single-TRP (transmission and reception point) configuration terminal may be configured with one CRS pattern per one LTE carrier, and a multi-TRP configuration terminal may have two CRS patterns per one LTE carrier. could be set. For example, in the Single-TRP configuration terminal, up to three CRS patterns per serving cell may be configured through the lte-CRS-PatternList1-r16 parameter. For another example, a CRS may be configured for each TRP in the multi-TRP configuration terminal. That is, the CRS pattern for TRP1 may be set through the lte-CRS-PatternList1-r16 parameter, and the CRS pattern for TRP2 may be set through the lte-CRS-PatternList2-r16 parameter. On the other hand, when two TRPs are configured as described above, whether to apply both the CRS patterns of TRP1 and TRP2 to a specific PDSCH (Physical Downlink Shared Channel) or whether to apply only the CRS pattern for one TRP is crs-RateMatch-PerCORESETPoolIndex It is determined through the -r16 parameter. When the crs-RateMatch-PerCORESETPoolIndex-r16 parameter is set to enabled, only one TRP CRS pattern is applied, and in other cases, both TRP CRS patterns are applied.

Table 16 shows the ServingCellConfig IE including the CRS pattern, and Table 17 shows the RateMatchPatternLTE-CRS IE including at least one parameter for the CRS pattern.

Table 16 - ServingCellConfig IE

Table 17 RateMatchPatternLTE-CRS IE

As mentioned above, only one CRS pattern per one LTE carrier may be configured in the Single-TRP configuration terminal. Therefore, in a multi-cell environment, when the adjacent LTE cell(s) uses a different CRS pattern from the terminal's serving cell (LTE-NR coexistence cell), the terminal may receive significant interference from the adjacent LTE cell(s). can experience Although the above problem can reduce interference to the UE through proper scheduling of the base station, scheduling is performed in units of resource blocks (RBs), and CRSs are mapped in units of resource elements (REs), so there is a limit. Hereinafter, the present invention proposes a method for minimizing interference from adjacent LTE cell(s) in the multi-cell environment as described above.

A. Embodiment 1 (Setting multiple CRS pattern information (s) for adjacent LTE cell (s))

According to one disclosure, the NR base station may set the CRS pattern information(s) of the neighboring LTE cell(s) to the NR terminal.

According to one disclosure, the NR base station may additionally set CRS pattern information for the neighboring LTE cell(s) in addition to the CRS pattern information for the serving cell (LTE-NR coexistence cell) to the NR terminal.

According to one disclosure, the CRS pattern information set by the NR base station to the NR terminal may include CRS pattern information(s) of a serving cell (LTE-NR coexistence cell) and neighboring LTE cell(s).

According to one disclosure, the CRS pattern information may include an indicator of whether the corresponding CRS pattern is for a serving cell or an adjacent LTE cell. Alternatively, an indicator indicating whether the corresponding CRS pattern is for rate-matching or interference cancellation may be included.

According to one disclosure, the configuration information may be transmitted from the NR base station to the NR terminal through higher layer signaling (eg, RRC signaling).

, 전송 power 등)를 수신할 수 있다. 상기 NR 기지국은 상기 LTE 서빙셀(들) 중 적어도 한 개 이상을 선택하여, 상기 선택된 LTE 서빙셀(들)의 CRS 패턴 관련 정보(들)을 기반으로 NR 단말에 설정할 CRS 패턴(들) 정보를 생성할 수 있다. 상기 LTE 서빙셀(들) 중 적어도 한 개를 선택하는 과정에 있어 전송 power가 큰 LTE 서빙셀(들)이 우선적으로 선택될 수 있다. 상기 NR 기지국은 상기 생성된 정보를 상기 NR 단말에 전송하여 상기 NR 단말에 인접 LTE 셀(들)에 대한 CRS 패턴을 설정할 수 있다.According to one disclosure, the NR base station, from the neighboring base station(s), CRS pattern related information (eg, LTE Cell ID, the number of CRS transmission ports) of each LTE serving cell(s) of the neighboring base station(s),

, transmit power, etc.) can be received. The NR base station selects at least one or more of the LTE serving cell(s), and based on the CRS pattern related information(s) of the selected LTE serving cell(s), CRS pattern(s) information to be set in the NR terminal can create In the process of selecting at least one of the LTE serving cell(s), the LTE serving cell(s) having high transmission power may be preferentially selected. The NR base station may transmit the generated information to the NR terminal to set a CRS pattern for the neighboring LTE cell(s) in the NR terminal.

, 수신 power 등)를 수신할 수 있다. 상기 NR 기지국은 상기 LTE 서빙셀(들) 중 적어도 한 개를 선택하여, 상기 선택된 LTE 서빙셀(들)의 CRS 패턴 관련 정보(들)을 기반으로 상기 단말에 설정할 CRS 패턴(들) 정보를 생성할 수 있다. 상기 LTE 서빙셀(들) 중 적어도 한 개를 선택하는 과정에 있어 수신 power가 큰 LTE 서빙셀(들)이 우선적으로 선택될 수 있다. 상기 NR 기지국은 상기 생성된 정보를 상기 단말에 전송하여 상기 단말에 인접 LTE 셀(들)에 대한 CRS 패턴을 설정할 수 있다.According to one disclosure, the NR base station is from a terminal (eg, a terminal supporting both LTE and NR) to the neighboring LTE serving cell(s) of the terminal existing in the same frequency band as the serving cell configured in the terminal. Information (eg, LTE Cell ID, the number of CRS transmission ports,

, reception power, etc.) can be received. The NR base station selects at least one of the LTE serving cell(s), and generates CRS pattern(s) information to be set in the terminal based on the CRS pattern related information(s) of the selected LTE serving cell(s) can do. In the process of selecting at least one of the LTE serving cell(s), the LTE serving cell(s) having a large reception power may be preferentially selected. The NR base station may transmit the generated information to the terminal to set a CRS pattern for the LTE cell(s) adjacent to the terminal.

According to one disclosure, the NR terminal receives at least one CRS pattern information(s) for a serving cell (LTE-NR coexistence cell) and adjacent LTE cell(s), and at least one of the received CRS pattern information(s) Demapping the PDSCH in a way that rate-matching based on one, that is, treating specific REs to which CRS(s) is mapped based on the CRS pattern information, as if the PDSCH is not mapped -map) can be done.

According to one disclosure, the NR terminal receives at least one CRS pattern information(s) for a serving cell (LTE-NR coexistence cell) and adjacent LTE cell(s), and at least one of the received CRS pattern information(s) De-map the PDSCH in such a way that interference cancellation is performed based on one, that is, the PDSCH is also mapped to specific REs to which CRS(s) are mapped based on the CRS pattern information. )can do.

According to one disclosure, the NR terminal receives at least one CRS pattern information(s) for a serving cell (LTE-NR coexistence cell) and adjacent LTE cell(s), and the serving cell (LTE-NR coexistence cell) of The received PDSCH is decoded in such a way that rate-matching is performed based on CRS pattern information(s) and interference cancellation is performed based on CRS pattern information(s) of the adjacent LTE cell(s). You can de-map.

According to one disclosure, the NR base station generates CRS pattern information (s) for the serving cell (LTE-NR coexistence cell) and the neighboring LTE cell (s) and transmits it to the terminal through RRC signaling, and the CRS pattern information ( It is possible to determine RE(s) to which CRS(s) can be mapped through the CRS(s), determine whether to map the PDSCH to the RE(s), and map the PDSCH according to the determination and transmit it to the UE.

According to one disclosure, among the RE(s), the RE(s) to which the CRS used in the LTE carrier of the serving cell (LTE-NR coexistence cell) is mapped is a rate-matching method, the neighboring LTE cell RE(s) to which CRS used in (s) are mapped may determine whether to map the PDSCH in an interference cancellation method.

According to one disclosure, among the RE(s), the RE(s) to which the CRS used in the LTE carrier of the serving cell (LTE-NR coexistence cell) is mapped is determined whether the PDSCH is mapped in a rate-matching manner. RE(s) to which CRS used in neighboring LTE cell(s) are mapped are used for interference cancellation and may not be involved in PDSCH mapping. In other words, the PDSCH is not mapped to RE(s) to which the CRS used in the LTE carrier of the serving cell (LTE-NR coexistence cell) is mapped, and the PDSCH may be mapped to the CRS used in the neighboring LTE cell(s). .

7A illustrates an operation of an NR base station according to an embodiment of the present disclosure. The NR base station acquires CRS pattern related information of the neighboring serving cell(s) (711), and generates configuration information to the terminal based on the obtained information (712), and transmits the generated configuration information to the terminal. (713). The NR base station may perform RE mapping of the PDSCH based on the configuration information to the terminal (714) and transmit the PDSCH (715).

7B illustrates an operation of an NR terminal according to an embodiment of the present disclosure. The NR terminal may receive CRS pattern related configuration information from the base station (721). Subsequently, the terminal may receive the PDSCH transmitted from the base station (722) and selectively perform an interference cancellation operation based on the received CRS pattern configuration information (723). For example, an interference cancellation operation may be performed for specific RE(s).

B. Example 2 (Interference Cancellation Method)

According to one disclosure, the information on one neighboring LTE cell among the information(s) on the CRS pattern information(s) of the neighboring LTE cell(s) transmitted by the NR base station of Embodiment 1 to the NR terminal is shown in Table 18 It may include at least part of the list.

(v-Shift)
- 인접 LTE 셀의 셀 ID(cell ID)
- 인접 LTE 셀의 cyclic prefix 타입(normal CP인지 extended CP인지 여부)- Bandwidth of LTE carrier of adjacent LTE cell (carrierBandwidthDL)
- Frequency band of the LTE carrier of the adjacent LTE cell (carrierFreqDL)
- MBSFN subframe configuration of neighboring LTE cells (mbsfn-SubframeConfigList)
- Number of CRS antenna ports of adjacent LTE cells (nrofCRS-Ports)
- of neighboring LTE cells

(v-Shift)
- Cell ID of the neighboring LTE cell (cell ID)
- Cyclic prefix type of neighboring LTE cell (whether normal CP or extended CP)

Table 18 Neighboring LTE Cell Information (1)

(v-Shift) 값을 획득할 수 있다.According to one disclosure, the information on one neighboring LTE cell among the information(s) on the CRS pattern information(s) of the neighboring LTE cell(s) transmitted by the NR base station of Example 1 to the NR terminal is shown in Table 19 It may include at least part of the list. According to one disclosure, the NR terminal performs a 'mod 6' operation on the cell ID value of an adjacent LTE cell.

(v-Shift) value can be obtained.

Table 19 Neighboring LTE Cell Information (2)

According to one disclosure, the information on one neighboring LTE cell among the information on the CRS pattern information(s) of the neighboring LTE cell(s) transmitted by the NR base station of the first embodiment to the NR terminal is at least from the list of Table 20. may include some. According to one disclosure, the NR terminal may assume that the cell ID of the adjacent LTE cell is the same as the cell ID of the NR cell, and that the cyclic prefix of the adjacent LTE cell is a normal CP.

(v-Shift)- Bandwidth of LTE carrier of adjacent LTE cell (carrierBandwidthDL)
- Frequency band of the LTE carrier of the adjacent LTE cell (carrierFreqDL)
- MBSFN subframe configuration of neighboring LTE cells (mbsfn-SubframeConfigList)
- Number of CRS antenna ports of adjacent LTE cells (nrofCRS-Ports)
- of neighboring LTE cells

(v-Shift)

Table 20 Neighboring LTE Cell Information (3)

According to one disclosure, the NR terminal assumes that the 'LTE radio frame boundary' and the 'NR radio frame boundary' of the serving cell (LTE-NR coexistence cell) are aligned, and the 'Slot in the LTE radio frame' index and, OFDM symbol index' in the slot can be determined. Alternatively, if not aligned, the base station may signal the difference (offset, the offset is, for example, a value in NR slot unit or LTE slot unit) to the terminal, and the terminal responds to the signaling Based on the 'slot index in the LTE radio frame and the OFDM symbol index in the slot' can be determined. Alternatively, it may signal whether or not they are aligned, and if they do not match, the difference (offset, the offset is, for example, a value in NR slot units or LTE slot units) may be additionally signaled. Alternatively, if the difference is not signaled, the NR terminal may perform assuming that the 'LTE radio frame boundary' and the 'NR radio frame boundary' of the serving cell (LTE-NR coexistence cell) are aligned.

According to one disclosure, the information on one neighboring LTE cell among the information on the CRS pattern information(s) of the neighboring LTE cell(s) transmitted by the NR base station of the first embodiment to the NR terminal is at least from the list in Table 21. may include some.

(v-Shift)
- 인접 LTE 셀의 셀 ID(cell ID)
- 인접 LTE 셀의 cyclic prefix 타입(normal CP인지 extended CP인지 여부)
- 'LTE의 radio frame boundary'와 'NR의 radio frame boundary'가 일치(align) 여부
- 'LTE의 radio frame boundary'와 'NR의 radio frame boundary'의 차이- Bandwidth of LTE carrier of adjacent LTE cell (carrierBandwidthDL)
- Frequency band of the LTE carrier of the adjacent LTE cell (carrierFreqDL)
- MBSFN subframe configuration of neighboring LTE cells (mbsfn-SubframeConfigList)
- Number of CRS antenna ports of adjacent LTE cells (nrofCRS-Ports)
- of neighboring LTE cells

(v-Shift)
- Cell ID of the neighboring LTE cell (cell ID)
- Cyclic prefix type of neighboring LTE cell (whether normal CP or extended CP)
- Whether 'LTE radio frame boundary' and 'NR radio frame boundary' are aligned
- Difference between 'LTE radio frame boundary' and 'NR radio frame boundary'

Table 21 Neighboring LTE Cell Information (4)

According to one disclosure, the terminal receiving the information on the neighboring LTE cell(s) as above generates a sequence(s) of the CRS(s) of the neighboring LTE cell(s) based on this, and the time- Mapping information(s) of a time-frequency resource may be obtained. At this time, the sequence of CRS(s) may be generated as follows. Here, m may be an index of a resource block to which the CRS is mapped.

According to one disclosure, based on the CRS sequence and time-frequency resource mapping information of the neighboring LTE cell(s) obtained as above, the channel between the neighboring LTE cell(s) and the terminal from the received CRS signal of the neighboring LTE cell(s) is can be estimated In this case, since the received CRS signal may be mixed with the PDSCH transmission signal of the NR cell due to interference, a process of processing the interference through a successive interference cancellation (SIC) process or the like is required. The SIC process may be configured as follows, for example, or may be configured in other ways.

The reception signal of the terminal can be described as Equation 1:

[Equation 1] Terminal reception signal

In Equation 1 above

는 NR 셀과 단말 간의 채널이며 PDSCH DM-RS 등을 통해 단말이 사전 획득한 값이다.l

is a channel between the NR cell and the UE, and is a value obtained in advance by the UE through the PDSCH DM-RS or the like.

는 NR 셀에서 전송하는 데이터이며 단말이 모르는 값이다●

is data transmitted from the NR cell and is a value unknown to the UE

는 인접 LTE 셀과 단말 간의 채널이며 단말이 모르는 값이다●

is a channel between the adjacent LTE cell and the terminal and is a value that the terminal does not know.

는 인접 LTE 셀의 CRS 신호이며 단말이 사전 획득한 값이다●

is the CRS signal of the neighboring LTE cell and is a value obtained in advance by the terminal

은 노이즈 신호이다●

is a noise signal

의 수신 파워가 대비

의 수신 파워 대비 크다는 가정 하에서, 단말은 다음 단계를 수행할 수 있다.

the receiving power of

Under the assumption that it is greater than the received power of , the terminal may perform the following steps.

채널 추정: 이 때

을 간섭으로 가정하므로, 추정할 신호, 즉 채널 값의 SINR은

이며 이 값이 너무 낮지 않으면 단말은

값을 얻어낼 수 있다.Step 1.

Channel Estimation: At this time

is assumed as interference, so the SINR of the signal to be estimated, i.e. the channel value, is

and if this value is not too low, the terminal

value can be obtained.

를 뺄 수 있다. 그러면 남은 신호(residual signal)은

이다.Step 2. At receive signal y

can be subtracted Then the residual signal is

to be.

신호 복호화: 이 때 복호화할 신호의 SNR은

이며 이 값이 너무 낮지 않으면 단말은 복호화를 성공할 수 있다. Step 3.

Signal decoding: At this time, the SNR of the signal to be decoded is

and if this value is not too low, the terminal may succeed in decoding.

8 illustrates an operation of an NR terminal according to the present embodiment. The NR terminal may receive CRS pattern related configuration information from the base station (801). Afterwards, the NR terminal receives the PDSCH (802), generates sequence(s) of CRS(s) based on the CRS pattern related configuration information obtained in step 801, and RE(s) to which CRS(s) are mapped can be determined (803). And using this, a decoding process can be performed through the SIC process (804).

C. Example 3 (Interference Cancellation / Rate match operation classification)

I. Example 3-1 (classification through terminal capability)

According to one disclosure, UE capability information for interference cancellation as in the first and second embodiments may be defined. According to one disclosure, the NR terminal may receive a 'UECapabilityEnquiry' message from the NR base station, and may respond to the NR base station including the 'UE capability information for interference cancellation'. The NR base station is configured so that a terminal capable of interference cancellation performs interference cancellation based on the 'UE capability information for interference cancellation' to which the terminal responds. And, the impossible terminal may be set to perform rate matching. Alternatively, the impossible terminal may be configured to follow the existing method.

9A illustrates an operation of an NR base station according to an embodiment of the present disclosure. The NR base station transmits a 'UECapabilityEnquiry' message to the NR terminal (911), receives a 'UE capability' message for interference cancellation capability from the terminal (912), and based on this, sets the operation (interference cancellation, rate matching) of the terminal can (913). Although not shown in FIG. 9-1, the NR base station may generate CRS pattern information of neighboring serving cell(s) and set it in the terminal.

9B illustrates an operation of an NR terminal according to an embodiment of the present disclosure. The NR terminal may receive a 'UECapabilityEnquiry' message from the NR base station (921), and may transmit a 'UE capability' message for interference cancellation capability to the base station (922). Then, by receiving the operation (interference cancellation, rate matching) configuration information of the terminal from the base station (923), it is possible to operate according to the configuration information. Although not shown in FIG. 9-2, the NR terminal may receive CRS pattern configuration information of neighboring serving cell(s) from the base station.

According to one disclosure, the NR terminal may operate in the conventional manner before receiving the 'information(s) configuration(s) of the adjacent LTE cell(s)' of the first and second embodiments. That is, the operation may be performed assuming that the NR PDSCH is mapped to the RE(s) for transmitting the CRS in the neighboring LTE cell(s). The NR terminal may receive 'information(s) configuration information(s) of adjacent LTE cell(s)' of the first and second embodiments. According to the setting, the NR terminal determines the RE(s) for transmitting the CRS in the neighboring LTE cell(s) based on the 'information(s) configuration information(s) of the neighboring LTE cell(s)', and the As the NR PDSCH is not mapped to the identified RE(s), that is, a rate-matching operation may be performed. The NR terminal receives the 'UECapabilityEnquiry' message from the NR base station, and responds to the NR base station including the 'UE capability information for interference cancellation' of the first and second embodiments. can According to one disclosure, thereafter, the terminal may operate according to the UE capability information. That is, the UE reporting that interference cancellation is not possible transmits the CRS in the neighboring LTE cell(s) based on the 'information(s) configuration information(s) of the neighboring LTE cell(s)' later. It is possible to determine the RE(s) to be used, and that the NR PDSCH is not mapped to the identified RE(s), that is, a rate-matching operation may be performed. On the other hand, the UE reporting that interference cancellation is possible transmits the CRS in the neighboring LTE cell(s) based on the 'information(s) configuration information(s) of the neighboring LTE cell(s)' later It is possible to determine the RE(s) to be used, determine that the NR PDSCH is mapped to the identified RE(s), and perform the interference cancellation operation according to the first and second embodiments. Table 22 is an example of a terminal operation, and shows the above description.

Table 22 Example of terminal operation

According to one disclosure, the NR terminal may operate in the conventional manner before receiving the 'information(s) configuration(s) of the adjacent LTE cell(s)' of the first and second embodiments. That is, the operation may be performed assuming that the NR PDSCH is mapped to the RE(s) for transmitting the CRS in the neighboring LTE cell(s). The NR terminal may receive 'information(s) configuration information(s) of adjacent LTE cell(s)' of the first and second embodiments. According to the setting, the NR terminal determines the RE(s) for transmitting the CRS in the neighboring LTE cell(s) based on the 'information(s) configuration information(s) of the neighboring LTE cell(s)', and the As the NR PDSCH is not mapped to the identified RE(s), that is, a rate-matching operation may be performed. The NR terminal receives the 'UECapabilityEnquiry' message from the NR base station, and responds to the NR base station including the 'UE capability information for interference cancellation' of the first and second embodiments. can According to one disclosure, the NR base station receives 'UE capability information for interference cancellation' from the terminal, and whether to perform a later operation (ie, 'rate matching' operation) or 'interference cancellation' It is possible to transmit configuration information about ' whether to perform the operation or not) to the terminal. The configuration information may be transmitted to the UE through higher layer signaling (RRC), control element (MAC CE), downlink control information (DCI), or the like. Thereafter, the terminal may operate according to the configuration information of the base station. Table 23 is an example of a terminal operation and shows the above description.

Table 23 Example of terminal operation

II. Example 3-2 (Instruction to distinguish between 'interference removal' pattern and 'rate match' pattern)

According to one disclosure, the CRS pattern information set by the NR base station to the NR terminal may include CRS pattern information(s) of a serving cell (LTE-NR coexistence cell) and neighboring LTE cell(s). The base station may transmit a control signal for at least some of the operations (eg, rate matching, interference cancellation, existing operation, etc.) corresponding to each of the CRS pattern information(s) to the terminal. The control signal may be transmitted to the terminal through higher layer signaling (RRC), MAC CE (Control Element), DCI (Downlink Control Information), or the like. The terminal may perform an operation according to a combination of at least one or more of the control signals.

i. RRC based setup

According to one disclosure, the NR terminal transmits 'CRS pattern information of adjacent LTE cell A' and 'action indication (interference cancellation indication) information' from the NR base station to higher layer signaling (eg, RRC signaling) can be received through The NR terminal receiving the information may perform an interference cancellation operation as in the above embodiments on the 'RE(s) to which the CRS of the neighboring LTE cell A is mapped' based on the reception control information.

According to one disclosure, the NR terminal transmits 'CRS pattern information of adjacent LTE cell A' and 'action indication (rate matching indication) information' from the NR base station to higher layer signaling (eg, RRC signaling) can be received through The NR terminal receiving the information may perform the same rate matching operation as in the above embodiments on the 'RE(s) to which the CRS of the adjacent LTE cell A is mapped' based on the reception control information.

According to one disclosure, the NR terminal may receive the 'CRS pattern information of the adjacent LTE cell A' as in the above embodiments from the NR base station through higher layer signaling (eg, RRC signaling). At this time, the UE assumes that the base station implicitly indicates 'interference cancellation', and based on the reception control information, the 'RE(s) to which the CRS of the neighboring LTE cell A is mapped' in the above embodiments Such an interference cancellation operation may be performed.

According to one disclosure, the NR terminal may receive the 'CRS pattern information of the adjacent LTE cell A' as in the above embodiments from the NR base station through higher layer signaling (eg, RRC signaling). At this time, the terminal assumes that the base station implicitly indicates 'rate matching', and based on the reception control information, the 'RE(s) to which the CRS of the neighboring LTE cell A is mapped' in the above embodiments A rate matching operation such as

According to one disclosure, the list of 'CRS pattern information of an adjacent LTE cell' or 'CRS pattern information of an adjacent LTE cell' is different from the RateMatchPatternLTE-CRS IE in Table 2, as shown in Tables 18, 19, 20, and 21 A separate IE including at least a part of the list may be indicated to the terminal.

10A illustrates an operation of an NR terminal according to an embodiment of the present disclosure. The NR terminal may receive CRS pattern information of the adjacent cell(s) through the RRC message from the base station (1011). Operation indication ('interference cancellation' or 'rate matching') information may be additionally included in the RRC configuration message (not shown). Alternatively, operation indication ('interference removal' or 'rate matching') information may be included in a separate RRC configuration message (not shown). Alternatively, an operation in the case of receiving CRS pattern information of adjacent cell(s) may be implicitly promised (not shown). Alternatively, an operation in the case of receiving CRS pattern information of the adjacent cell(s) may be implicitly promised according to the capability of the terminal (not shown). The UE may perform 'interference removal' or 'rate matching' operation according to the received RRC configuration information (1012).

ii. RRC + L1/L2 based setup

According to one disclosure, the NR terminal may receive the 'CRS pattern information of the neighboring LTE cell A' as in the above embodiments from the NR base station through higher layer signaling (eg, RRC signaling). Additionally, 'operation instruction (interference cancellation instruction) information' may be received through, for example, MAC CE or DCI. The NR terminal receiving the information may perform an interference cancellation operation as in the above embodiments on the 'RE(s) to which the CRS of the neighboring LTE cell A is mapped' based on the reception control information. According to one disclosure, before receiving the 'operation instruction (interference cancellation instruction) information', the terminal may operate under the assumption of 'rate matching'. According to one disclosure, the above 'operation indication information' may be newly defined in MAC CE or newly defined in DCI format. According to one disclosure, when 'action indication (interference removal indication) information' is defined in the DCI format, the size of the field containing the 'action indication (interference removal indication) information' is 'adjacent LTE' set through higher layer signaling It may be based on the number of 'CRS pattern information(s) of the cell. That is, when information of two adjacent cells is received, it may be 2 bits, and when information of three adjacent cells is received, it may be 3 bits. Through this, the base station can instruct the terminal to independently process each 'RE(s) to which the CRS of an adjacent LTE cell is mapped'.

According to one disclosure, the NR terminal may receive the 'CRS pattern information of the neighboring LTE cell A' as in the above embodiments from the NR base station through higher layer signaling (eg, RRC signaling). Additionally, 'operation indication (rate matching indication) information' may be received through, for example, MAC CE or DCI. The NR terminal receiving the information may perform the same rate matching operation as in the above embodiments on the 'RE(s) to which the CRS of the adjacent LTE cell A is mapped' based on the reception control information. According to one disclosure, before receiving the 'operation instruction (rate matching instruction) information', the terminal may operate under the assumption of 'rate matching'. According to one disclosure, the above 'operation indication information' may be newly defined in MAC CE or newly defined in DCI format. According to one disclosure, when 'action indication (rate matching indication) information' is defined in the DCI format, the size of the field containing the 'action indication (rate matching indication) information' is 'adjacent LTE' set through higher layer signaling. It may be based on the number of 'CRS pattern information(s) of the cell. That is, when information of two adjacent cells is received, it may be 2 bits, and when information of three adjacent cells is received, it may be 3 bits. Through this, the base station can instruct the terminal to independently process each 'RE(s) to which the CRS of an adjacent LTE cell is mapped'.

According to one disclosure, the NR terminal may receive the 'CRS pattern information of the neighboring LTE cell A' as in the above embodiments from the NR base station through higher layer signaling (eg, RRC signaling). Additionally, 'operation instruction ('interference removal', 'rate matching') information 1 bit' may be received through, for example, MAC CE or DCI. The terminal receiving the information performs the 'interference cancellation' or 'rate matching' operation as in the above embodiments on the 'RE(s) to which the CRS of the adjacent LTE cell A is mapped' based on the reception control information. can According to one disclosure, the above 'operation indication information' may be newly defined in MAC CE or newly defined in DCI format. According to one disclosure, when 'operation instruction ('interference removal', 'rate matching') information' is defined in the DCI format, the field containing the 'operation instruction ('interference removal', 'rate matching') information' The size may be based on the number of 'CRS pattern information(s) of adjacent LTE cells' set through higher layer signaling. That is, when information of two adjacent cells is received, it may be 2 bits, and when information of three adjacent cells is received, it may be 3 bits. Through this, the base station can instruct the terminal to independently process each 'RE(s) to which the CRS of an adjacent LTE cell is mapped'.

According to one disclosure, the NR terminal may receive the 'CRS pattern information of the neighboring LTE cell A' as in the above embodiments from the NR base station through higher layer signaling (eg, RRC signaling). Additionally, 'operation instruction ('interference removal', 'rate matching') information' may be received through DCI. The 'operation indication' information may be indicated through values of at least some field(s) among field(s) already existing in the DCI format. For example, the value of the 'Modulation and coding scheme' field in the DCI format may be used. Assuming that the range of the value of the field is 0 to 31, if a value lower than the 'specific value' is indicated to the terminal through the DCI format, the terminal calls this 'interference cancellation' and is higher than or equal to the 'specific value' When the value is indicated to the terminal through the DCI format, the terminal may understand this as indicating 'rate matching' and operate. Or conversely, when a value lower than the 'specific value' is indicated to the terminal through DCI format, the terminal is referred to as 'rate matching'. It can be understood and operated as 'interference cancellation' as indicated. At this time, the NR terminal can process all of the configured 'RE(s) to which CRS of all neighboring LTE cell(s)' are mapped in the same way (ie, 'all interference cancellation' or 'all rate matching'). . According to one disclosure, the 'specific value' is predefined through the NR standard document (ie, stored in advance in the terminal), or to the terminal through control information (eg, RRC setting) set by the NR base station to the terminal can be transmitted.

According to one disclosure, the NR terminal may receive the 'CRS pattern information of the neighboring LTE cell A' as in the above embodiments from the NR base station through higher layer signaling (eg, RRC signaling). Additionally, 'operation instruction ('interference removal', 'rate matching') information' may be received through DCI. The 'operation indication' information may be indicated through values of at least some field(s) among field(s) already existing in the DCI format. For example, the value of the 'DMRS sequence initialization' field in DCI format can be used. For example, when 0 is indicated as the field value, the UE can understand and operate as the PDSCH DMRS sequence initialization value corresponding to the field value is set and 'rate matching' for CRS is also indicated. Meanwhile, when 1 is indicated as the field value, the UE can understand and operate as the PDSCH DMRS sequence initialization value corresponding to the field value is set and 'interference control' for CRS is also indicated. (Or vice versa.) At this time, the NR terminal uses the same method (ie, 'all interference cancellation' or 'all rate matching'). According to one disclosure, the mapping between the 'DMRS sequence initialization' field value and the 'rate matching' or 'interference control' operation for the CRS is predefined through the NR standard document (that is, stored in advance in the terminal), or the NR base station It may be transmitted to the terminal through control information set in the terminal (eg, RRC configuration).

10B illustrates an operation of an NR terminal according to an embodiment of the present disclosure. The NR terminal may receive CRS pattern information of the adjacent cell(s) through the RRC message from the base station (1021). The NR terminal may receive DCI from the base station and perform 'interference cancellation' or 'rate matching' operation according to operation indication information included in the DCI (1022). The operation indication information may be received through MAC CE instead of DCI (not shown).

III. Example 3-3 ('multi-TRP' scenario)

According to one disclosure, an NR terminal receiving data from a plurality of TRPs may determine whether 'interference removal' or 'rate matching' for each TRP according to the type of TRP. For example, when each of the plurality of TRPs points to the base station of the LTE-NR coexistence cell, CRS 'rate matching' may be required because the interference signal strength received from the TRP closest to the terminal is very large compared to the NR signal strength. . On the other hand, since the ratio of the NR signal strength to the CRS signal strength from the remaining TRP may be relatively small, the CRS 'interference cancellation' operation may be appropriate. Or conversely, it may be appropriate to perform CRS 'interference cancellation' from the TRP closest to the distance, but perform CRS 'rate matching' operation from the remaining TRPs. Accordingly, the NR terminal may perform a 'interference cancellation' operation to remove a CRS from a specific TRP, and a 'rate matching' operation for a CRS from another TRP.

At this time, the TRP for performing CRS 'interference removal' and CRS 'rate matching' operation is predefined through the NR standard document (ie, stored in advance in the terminal), or control information set by the NR base station to the terminal (for example, For example, it may be transmitted to the terminal through RRC configuration). The TRP defined above or set through control information may be expressed as an index value set for each CORESET, for example, a CORESETPoolIndex value, a physical cell ID (hereinafter PCID), an SSB index, and the like. For example, the CRS 'rate matching' operation is limitedly applied to CORESET set to CORESETPoolIndex = 0, and the CRS 'interference removal' operation can be applied limitedly to CORESET set to CORESETPoolIndex = 1.

11 illustrates an operation of an NR terminal according to the present embodiment. The NR terminal receiving data from a plurality of TRPs may receive configuration information for each TRP from the base station (1101). Later, the terminal receives the PDSCH(s) from a plurality of TRPs (1102), and based on the configuration information received from the base station, 'interference cancellation' or 'rate matching' operation for each PDSCH received for each TRP can be performed. (1103).

IV. Example 3-4 (Operation in MBSFN)

According to one disclosure, the NR terminal receives the mbsfn-SubframeConfigList from the NR base station through the RateMatchPatternLTE-CRS IE of Table 2, and corresponds to the MBSFN subframe of the LTE among the slots of the serving cell (LTE-NR coexistence cell) (overlapping ) slot(s), and interference cancellation according to the above embodiments may not be performed in the identified slots. A rate matching operation may be performed in the identified slot(s). Alternatively, rate matching may be performed only on CRS RE(s) present in the MBSFN subframe.

According to one disclosure, the NR terminal receives the 'mbsfn-SubframeConfigList of adjacent LTE cell(s)' from the NR base station, and corresponds to the MBSFN subframe of the LTE among the slots of the serving cell (LTE-NR coexistence cell) (overlapping ) slots, and interference cancellation according to the above embodiments may not be performed in the identified slot(s). A rate matching operation may be performed in the identified slot(s). Alternatively, rate matching may be performed only on CRS RE(s) present in the MBSFN subframe.

D. Embodiment 4 (NR PDSCH mapping only to CRS RE(s) of some slots)

According to one disclosure, the mapping of PDSCH of NR to CRS RE(s) of LTE of the above embodiments may be applied to some slots of NR slots. The NR PDSCH may not be mapped to CRS RE(s) of LTE included in the remaining slots except for some of the applied slots.

정보를 추정하는 데에 사용할 수 있다.According to one disclosure, the NR base station is information on the 'slot to which mapping of NR PDSCH to CRS RE(s) of LTE is applied' (eg, at least one of a plurality of defined slot pattern(s)) pattern, list of slots, etc.) can be transmitted to the NR terminal. Based on the information, the UE performs the interference cancellation operation according to the embodiments in 'slots in which NR PDSCH is mapped to LTE CRS RE(s)', and rate matching in the remaining slots. matching) operation can be performed. In addition, in the remaining slots, the NR terminal receives the CRS(s) of LTE and

It can be used to estimate information.

According to one disclosure, the LTE base station is information on the 'slot to which mapping of NR PDSCH to LTE CRS RE(s) is applied' (eg, at least one of a plurality of defined slot pattern(s)) pattern, list of slots, etc.) can be transmitted to the LTE terminal. Based on the information, the LTE terminal may discard CRS RE(s) received in 'slots to which mapping of NR PDSCH to LTE CRS RE(s) is applied' for channel estimation without using it for channel estimation. have.

E. Example 5 (Combination)

According to one disclosure, an NR base station and an NR terminal may operate according to 'some or one of the above embodiments' or 'a combination of the above embodiments'.

In order to perform the above-described embodiments of the disclosure, a transceiver, a memory, and a processor of a terminal and a base station are shown in FIGS. 12 and 13, respectively. In the above-described embodiments, a method for setting CRS pattern information for neighboring LTE cell(s), a method for setting an operation ('interference cancellation' or 'rate matching'), an operation instruction method, a terminal capability information exchange method, etc. are shown. . To perform this, the transceiver, memory, and processor of the base station and the terminal must operate according to the above-described embodiments, respectively.

12 illustrates a structure of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 12 , the terminal may include a transceiver 1201 , a memory 1202 , and a processor 1203 . However, the components of the terminal are not limited to the above-described example. For example, the terminal may include more or fewer components than the aforementioned components. In addition, the transceiver 1201 , the memory 1202 , and the processor 1203 may be implemented in the form of a single chip.

According to an embodiment of the present disclosure, the transceiver 1201 may transmit/receive a signal to/from the base station. The above-described signal may include control information and data. To this end, the transceiver 1001 may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. Also, the transceiver 1201 may receive a signal through a wireless channel and output it to the processor 1203 , and transmit the signal output from the processor 1203 through a wireless channel.

According to an embodiment of the present disclosure, the memory 1202 may store programs and data necessary for the operation of the terminal. Also, the memory 1202 may store control information or data included in a signal transmitted and received by the terminal. The memory 1202 may be configured as a storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM, and DVD. Also, the memory 1202 may be composed of a plurality of memories. According to an embodiment of the present disclosure, the memory 1202 may store a program for removing and decoding interference from some RE(s) in the PDSCH of the UE.

According to an embodiment of the present disclosure, the processor 1203 may control a series of processes in which the terminal may operate according to the above-described embodiments of the present disclosure. For example, the processor 1203 may control decoding and removing interference from some RE(s) in the PDSCH according to embodiments of the present disclosure.

Specifically, the processor 1203 receives the CRS pattern setting related information for the neighboring LTE cell(s) from the base station, and based on the CSR pattern setting related information for the neighboring LTE cell(s) from the base station, within the PDSCH received from the base station. In some RE(s), each configuration of a UE having an interference cancellation operation or a rate matching operation may be controlled.

Specifically, the processor 1203 receives the CRS pattern setting related information for the neighboring LTE cell(s) from the base station, and the CSR pattern setting related information for the neighboring LTE cell(s) from the base station and higher layer signaling or lower layer signaling ( Based on the operation indication information transmitted through DCI or MAC CE), it is possible to control each configuration of a terminal having an interference cancellation operation or a rate matching operation in some RE(s) in the PDSCH received from the base station.

In addition, the processor 1203 may include a plurality of processors, by executing a program stored in the memory 1202, according to embodiments of the present disclosure, removing interference from some RE(s) in the PDSCH and decoding method can be done

13 illustrates a structure of a base station according to an embodiment of the present disclosure.

Referring to FIG. 13 , the base station may include a transceiver 1301 , a memory 1302 , and a processor 1303 . However, the components of the base station are not limited to the above-described example. For example, the terminal may include more or fewer components than the aforementioned components. In addition, the transceiver 1301 , the memory 1302 , and the processor 1303 may be implemented in the form of a single chip.

According to an embodiment of the present disclosure, the transceiver 1301 may transmit/receive a signal to/from the terminal. The above-described signal may include control information and data. To this end, the transceiver 1301 may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts a received signal. Also, the transceiver 1301 may receive a signal through a wireless channel and output it to the processor 1303 , and transmit the signal output from the processor 1303 through a wireless channel.

According to an embodiment of the present disclosure, the memory 1302 may store programs and data necessary for the operation of the base station. In addition, the memory 1302 may store control information or data included in a signal transmitted and received by the base station. The memory 1302 may be configured as a storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM, and DVD. Also, the memory 1302 may be composed of a plurality of memories. According to an embodiment of the present disclosure, the memory 1302 may store a program for generation of CRS pattern setting related information for the neighboring LTE cell(s) of the base station and transmission to the terminal. Alternatively, the memory 1302 is a downlink control channel containing information instructing a program and an interference cancellation operation or a rate matching operation for generation of CRS pattern setting related information for the neighboring LTE cell(s) of the base station and transmission to the terminal, or A program for MAC CE generation and transmission may be stored. The memory 1302 may additionally store a data mapping determination program to specific RE(s) in the PDSCH.

According to an embodiment of the present disclosure, the processor 1303 may control a series of processes so that the base station operates according to the above-described embodiment of the present disclosure. For example, the processor 1303 generates and transmits CRS pattern configuration information for neighboring LTE cell(s), generation and transmission of information instructing an interference cancellation operation or a rate matching operation, the 'configuration information' and 'operation Each configuration of the base station may be controlled to determine data mapping to specific RE(s) in the PDSCH based on 'indication information'.

In addition, the processor 1303 may include a plurality of processors, and by executing a program stored in the memory 1302 , generates and generates CRS pattern setting related information for the adjacent LTE cell(s) according to embodiments of the present disclosure; A method of instructing a transmission method, an interference cancellation operation or a rate matching operation, and a symbol mapping method to specific RE(s) in the PDSCH based on the 'configuration information' and 'operation indication information' may be performed.

Methods according to the embodiments described in the claims or specifications of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium or computer program product storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium or computer program product are configured for execution by one or more processors in an electronic device (device). One or more programs include instructions for causing an electronic device to execute methods according to embodiments described in a claim or specification of the present disclosure.

Such programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable ROM (EEPROM: Electrically Erasable Programmable Read Only Memory), magnetic disc storage device, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or any other form of It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all thereof. In addition, a plurality of each configuration memory may be included.

In addition, the program accesses through a communication network composed of a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. It may be stored in an attachable storage device that can be accessed. Such a storage device may be connected to a device implementing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may be connected to the device performing the embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, components included in the present disclosure are expressed in the singular or plural according to the specific embodiments presented. However, the singular or plural expression is appropriately selected for the context presented for convenience of description, and the present disclosure is not limited to the singular or plural element, and even if the element is expressed in plural, it is composed of the singular or singular. Even an expressed component may be composed of a plurality of components.

On the other hand, the embodiments of the present disclosure disclosed in the present specification and drawings are only presented as specific examples to easily explain the technical content of the present disclosure and help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is apparent to those of ordinary skill in the art to which the present disclosure pertains that other modified examples can be implemented based on the technical spirit of the present disclosure. In addition, each of the above embodiments may be operated in combination with each other as needed. For example, an embodiment of the present disclosure and parts of another embodiment may be combined to operate a base station and a terminal. In addition, the embodiments of the present disclosure are applicable to other communication systems, and other modifications based on the technical spirit of the embodiments may also be implemented. For example, the embodiments may also be applied to an LTE system, a 5G or NR system, and the like.

Claims (1)

In the method of a terminal of a wireless communication system,
Receiving cell specific reference signal (CRS) pattern related configuration information from the base station;
Receiving a physical downlink shared channel (PDSCH) from the base station; and
Based on the CRS pattern related configuration information, the method comprising the step of performing interference cancellation for the PDSCH.

Images