KR102648509B1 - Method and apparatus for csi reporting in wireless communication system - Google Patents

Abstract

This disclosure relates to a communication technique and system that integrates a 5G communication system with IoT technology to support higher data transmission rates after the 4G system. This disclosure provides intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. ) can be applied. The present invention discloses a method for measuring channel and interference of a base station and a terminal, a method for processing channel state information, and a method and device for reporting channel state information for efficiently measuring channel characteristics and interference characteristics that vary depending on supported services.

Description

Method and apparatus for reporting channel state information in a mobile communication system {METHOD AND APPARATUS FOR CSI REPORTING IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to a wireless communication system, and more specifically, a method of measuring channel and interference of a base station and a terminal for efficiently measuring channel characteristics and interference characteristics that vary depending on the supported service, a method of processing channel state information, and channel state information. It concerns reporting methods and devices.

In order to meet the increasing demand for wireless data traffic following the commercialization of the 4G communication system, efforts are being made to develop an improved 5G communication system or pre-5G communication system. For this reason, the 5G communication system or pre-5G communication system is called a Beyond 4G Network communication system or a Post LTE system. To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (such as the 60 GHz band). In order to alleviate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, the 5G communication system uses beamforming, massive array multiple input/output (massive MIMO), and full dimension multiple input/output (FD-MIMO). ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, to improve the network of the system, the 5G communication system uses advanced small cells, advanced small cells, cloud radio access networks (cloud RAN), and ultra-dense networks. , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation. Technology development is underway. In addition, the 5G system uses FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), which are advanced coding modulation (ACM) methods, and advanced access technologies such as FBMC (Filter Bank Multi Carrier) and NOMA. (non orthogonal multiple access), and SCMA (sparse code multiple access) are being developed.

Meanwhile, the Internet is evolving from a human-centered network where humans create and consume information to an IoT (Internet of Things) network that exchanges and processes information between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection to cloud servers, etc., is also emerging. In order to implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, sensor networks for connection between things, and machine to machine communication (Machine to Machine) are required to implement IoT. , M2M), and MTC (Machine Type Communication) technologies are being researched. In the IoT environment, intelligent IT (Internet Technology) services that create new value in human life can be provided by collecting and analyzing data generated from connected objects. IoT is used in fields such as smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliances, and advanced medical services through the convergence and combination of existing IT (information technology) technology and various industries. It can be applied to .

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, Machine to Machine (M2M), and Machine Type Communication (MTC) are implemented through 5G communication technologies such as beam forming, MIMO, and array antennas. There is. 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 the convergence of 5G technology and IoT technology.

Meanwhile, NR (New Radio access technology), a new 5G communication, is designed to allow various services to be freely multiplexed in time and frequency resources. Accordingly, waveform/numerology, etc. and reference signals are dynamically adjusted according to the needs of the service. It can be assigned randomly or freely. In order to provide optimal services to terminals in wireless communication, optimized data transmission through measurement of channel quality and interference amount is important, and therefore accurate measurement of channel status is essential. However, unlike 4G communications, where channel and interference characteristics do not change significantly depending on frequency resources, in the case of 5G channels, channel and interference characteristics vary greatly depending on the service, so they can be measured separately at the VRG (Vertical Resource Group) level. A subset of support is needed.

The object of the present invention is to provide a method and corresponding device for providing data transmission and reception for 5G communication services. In particular, in order to satisfy 5G communication services with various requirements, a method for operating transmission time sections of various lengths, a corresponding method for transmitting and receiving data from a base station and a terminal, and a corresponding device are provided.

Another object of the present invention is to support various services such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), ultra-reliable and low-latency communications (URLLC), and forward compatible resource (FCR). In order to measure and report channel state information and interference characteristics that vary depending on the characteristics of the service, a channel state information subset according to frequency units and a channel state information reporting method optimized for the service are proposed.

Another purpose of the present invention is to explain a method of operating a base station and a terminal in a delay reduction mode when the time required for signal processing of the base station and the terminal can be reduced in an LTE system using FDD or TDD.

Another object of the present invention is to provide a control channel structure that can be flexibly configured to meet 5G wireless communication requirements.

The present invention to solve the above problems is a control signal processing method in a wireless communication system, comprising: receiving a first control signal transmitted from a base station; processing the received first control signal; And transmitting a second control signal generated based on the processing to the base station.

According to an embodiment of the present invention, a method and corresponding device for providing data transmission and reception for 5G communication services are provided. In particular, in order to satisfy 5G communication services with various requirements, we provide a method for operating transmission time sections of various lengths, a method for transmitting and receiving data from a base station and a terminal, and a corresponding device. Meanwhile, various other effects will be disclosed directly or implicitly in the detailed description according to embodiments of the present invention to be described later.

In addition, according to another embodiment of the present invention, when different services are supported according to time and frequency resources, a subset for channel status information reporting can be divided and set according to frequency resources according to the service, so that the service supported by the corresponding terminal Different channel conditions can be reported depending on the type of service causing interference. Additionally, when reporting the channel status, different types of channel status reports may be made depending on the service supported by the terminal.

In addition, according to another embodiment of the present invention, a method of operating a base station and a terminal in a delay reduction mode is provided so that delay time can be reduced when transmitting uplink and downlink data.

In addition, according to another embodiment of the present invention, by providing a control channel structure with a flexible structure for transmitting downlink control signals, it is possible to effectively operate a 5G wireless communication system that simultaneously supports various services with different requirements. Let it happen.

Figure 1a is a diagram showing the basic structure of the time-frequency domain in the LTE system.
Figure 1b is a diagram showing an example in which 5G services are multiplexed and transmitted in one system.
Figure 1C is a diagram showing a 1-1 embodiment of a communication system to which the present invention is applied.
Figure 1D is a diagram showing a first and second embodiment of a communication system to which the present invention is applied.
Figure 1e is a diagram showing subframe structures proposed in the present invention.
Figure 1f is a diagram showing the situation to be solved by the present invention.
Figure 1g is a diagram showing the 1-1 embodiment proposed by the present invention.
Figure 1h is a diagram showing the first and second embodiments proposed by the present invention.
Figure 1i is a diagram showing embodiments 1-3 proposed in the present invention.
Figure 1j is a diagram showing a base station device according to the present invention.
Figure 1k is a diagram showing a terminal device according to the present invention.
Figure 2a is a diagram showing the radio resource configuration of the LTE system.
Figure 2b is a diagram illustrating the radio resource configuration of data such as eMBB, URLLC, and mMTC in the NR system.
Figure 2c is a diagram illustrating URLLC data and CSI-RS transmission in the NR system.
Figure 2d is a diagram illustrating that other services such as URLLC and FCR cause interference to eMBB transmission in the NR system.
Figure 2e is a diagram illustrating that in the NR system, a Transmission Reception Point (TRP) transmits different beams for each subband when transmitting CSI-RS, or a TRP located in a different geographical location simultaneously transmits at different frequencies.
Figure 2f is a flowchart showing the operation of the terminal in the present invention.
Figure 2g is a flowchart showing the operation of the base station in the present invention.
Figure 2h is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention.
Figure 2i is a block diagram showing the internal structure of a base station according to an embodiment of the present invention.
Figure 3a is a diagram showing the downlink time-frequency domain transmission structure of the LTE or LTE-A system.
Figure 3b is a diagram showing the uplink time-frequency domain transmission structure of the LTE or LTE-A system.
Figure 3c is a diagram showing data for eMBB, URLLC, and mMTC allocated in frequency-time resources in a communication system.
Figure 3d is a diagram showing data for eMBB, URLLC, and mMTC allocated in frequency-time resources in a communication system.
Figure 3e is a diagram showing a structure in which one transport block is divided into several code blocks and a CRC is added according to an embodiment.
Figure 3f is a diagram showing a coding structure in which an outer code is applied according to an embodiment.
Figure 3g is a block diagram showing whether or not an outer code is applied according to an embodiment.
Figure 3h is a diagram showing terminal operation according to the 3-1 embodiment.
Figure 3i is a diagram showing terminal operation according to the 3-2 embodiment.
Figure 3j is a diagram showing terminal operation according to the 3-3 embodiment.
Figure 3k is a diagram showing terminal operation according to the 3-5 embodiment.
Figure 3l is a block diagram showing the structure of a terminal according to embodiments.
Figure 3m is a block diagram showing the structure of a base station according to embodiments.
Figure 3n is a flow chart to explain an embodiment of the case where the base station determines the timing of the second signal through DCI to the terminal according to the present invention.
Figure 3o is a flow chart to explain an embodiment of the case where the base station determines the timing of the second signal through DCI to the terminal according to the present invention.
Figure 3p is a flow chart to explain an embodiment of the case where the base station determines the timing of the second signal through DCI to the terminal according to the present invention.
Figure 4a is a diagram showing an example in which 5G services are multiplexed and transmitted in one system.
Figure 4b is a diagram showing PDCCH and EPDCCH, which are downlink control channels of LTE.
Figure 4c is a diagram showing an example of a downlink control channel basic unit considered by the present invention.
Figure 4d is a diagram showing an example of downlink control channel setting in the 4-1 embodiment of the present invention.
Figure 4e is a diagram showing an example of downlink control channel resource allocation in the 4-1 embodiment of the present invention.
Figure 4f is a diagram showing an example of downlink transmission according to the 4-1 embodiment of the present invention.
Figure 4g is a diagram illustrating the base station and terminal procedures according to embodiment 4-1-1 of the present invention.
Figure 4h is a diagram illustrating the base station and terminal procedures according to embodiment 4-1-2 of the present invention.
Figures 4i and 4ia are diagrams illustrating base station and terminal procedures according to embodiment 4-1-3 of the present invention.
Figure 4j is a diagram showing an example of downlink transmission according to the 4-1 embodiment of the present invention.
Figure 4k is a diagram illustrating the base station and terminal procedures according to embodiment 4-1-4 of the present invention.
Figure 4l is a diagram showing the base station and terminal procedures according to embodiment 4-1-5 of the present invention.
Figure 4m is a diagram showing the 4-2 embodiment of the present invention.
Figure 4n is a diagram showing an example of resource allocation for a control channel in the 4-2 embodiment of the present invention.
Figure 4o is a diagram illustrating an example of DCI division according to Example 4-2-1.
Figure 4p is a diagram illustrating the base station and terminal procedures according to Example 4-2-1.
Figure 4q is a diagram showing an example of DCI division according to Example 4-2-2.
Figure 4r is a diagram illustrating the base station and terminal procedures according to Example 4-2-2.
FIG. 4S is a diagram illustrating an example of DCI division according to Example 4-2-3.
Figure 4t is a diagram showing an example of a frame structure according to Example 4-2-3.
Figure 4u is a diagram illustrating the base station and terminal procedures according to Example 4-2-3.
Figure 4v is a block diagram showing the internal structure of a terminal according to an embodiment.
Figure 4w is a block diagram showing the internal structure of a base station according to an embodiment.

Hereinafter, embodiments of the present invention will be described in detail with the accompanying drawings. Additionally, when describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. The terms described below are defined in consideration of the functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to provide common knowledge in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

<First embodiment>

In general, mobile communication systems were developed to provide voice services while ensuring user activity. However, mobile communication systems are gradually expanding their scope to include not only voice but also data services, and have now developed to the point where they can provide high-speed data services. However, in the mobile communication systems currently providing services, there is a shortage of resources and users demand higher-speed services, so a more advanced mobile communication system is required.

In response to these demands, work on specifications for LTE (Long Term Evolution) is in progress at 3GPP (The 3rd Generation Partnership Project) as one of the systems being developed as a next-generation mobile communication system. LTE is a technology that implements high-speed packet-based communication with a transmission speed of up to 100 Mbps. To this end, various methods are being discussed. For example, there are ways to simplify the network structure to reduce the number of nodes located on the communication path, or ways to bring wireless protocols as close to the wireless channel as possible.

The LTE system adopts the HARQ (Hybrid Automatic Repeat reQuest) method, which retransmits the data in the physical layer when a decoding failure occurs in the initial transmission. In the HARQ method, when the receiver fails to decode data accurately, the receiver transmits information (NACK; Negative Acknowledgment) informing the transmitter of the decoding failure, allowing the transmitter to retransmit the data in the physical layer. The receiver improves data reception performance by combining the data retransmitted by the transmitter with data that previously failed to decode. Additionally, when the receiver accurately decodes the data, it can transmit information (ACK; Acknowledgment) indicating successful decoding to the transmitter, allowing the transmitter to transmit new data.

Figure 1a is a diagram showing the basic structure of the time-frequency domain, which is a radio resource region where the data or control channel is transmitted in the downlink in the LTE system.

In Figure 1a, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol. Nsymb (1a-02) OFDM symbols are gathered to form one slot (1a-06), and two slots are gathered to form one subframe (1a-05). Compose. The length of the slot is 0.5ms, and the length of the subframe is 1.0ms. And the radio frame (1a-14) is a time domain unit consisting of 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth consists of a total of NBW (1a-04) subcarriers.

The basic unit of resources in the time-frequency domain is a resource element (1a-12, Resource Element; RE), which can be expressed as an OFDM symbol index and a subcarrier index. A resource block (1a-08, Resource Block; RB or Physical Resource Block; PRB) is defined as Nsymb (1a-02) consecutive OFDM symbols in the time domain and NRB (1a-10) consecutive subcarriers in the frequency domain. do. Therefore, one RB (1a-08) is composed of Nsymb x NRB REs (1a-12). Generally, the minimum data transmission unit is the RB unit. In an LTE system, Nsymb = 7 and NRB = 12, and NBW and NRB are proportional to the bandwidth of the system transmission band. The data rate increases in proportion to the number of RBs scheduled for the terminal. The LTE system defines and operates six transmission bandwidths. In the case of an FDD system that operates by dividing downlink and uplink by frequency, the downlink transmission bandwidth and uplink transmission bandwidth may be different. The channel bandwidth represents the RF bandwidth corresponding to the system transmission bandwidth. Table 1a-01 shows the correspondence between system transmission bandwidth and channel bandwidth defined in the LTE system. For example, an LTE system with a 10 MHz channel bandwidth has a transmission bandwidth of 50 RBs.

[Table 1a-01]

In the case of downlink control information, it is transmitted within the first N OFDM symbols within the subframe. Typically N = {1, 2, 3}. Therefore, the N value varies for each subframe depending on the amount of control information to be transmitted in the current subframe. The control information includes a control channel transmission section indicator indicating how many OFDM symbols the control information is transmitted over, scheduling information for downlink data or uplink data, HARQ ACK/NACK signals, etc.

In the LTE system, scheduling information for downlink data or uplink data is transmitted from the base station to the terminal through downlink control information (DCI). Uplink (UL) refers to a wireless link through which a terminal transmits data or control signals to a base station, and downlink (DL) refers to a wireless link through which a base station transmits data or control signals to a terminal. DCI defines various formats, whether it is scheduling information for uplink data (UL (uplink) grant) or scheduling information for downlink data (DL (downlink) grant), and whether it is compact DCI with small control information. It is operated by applying a determined DCI format depending on whether spatial multiplexing using multiple antennas is applied, and whether DCI is for power control. For example, DCI format 1, which is scheduling control information (DL grant) for downlink data, is configured to include at least the following control information.

- Resource allocation type 0/1 flag: Notifies whether the resource allocation method is type 0 or type 1. Type 0 applies the bitmap method to allocate resources in RBG (resource block group) units. The basic unit of scheduling in the LTE system is the RB (resource block) expressed as time and frequency domain resources, and the RBG is composed of a plurality of RBs and becomes the basic unit of scheduling in the type 0 method. Type 1 allows allocation of a specific RB within the RBG.

- Resource block assignment: Notifies the RB allocated to data transmission. The resources represented are determined by system bandwidth and resource allocation method.

- Modulation and coding scheme (MCS): Notifies the modulation method used for data transmission and the size of the transport block, which is the data to be transmitted.

- HARQ process number: Notifies the HARQ process number.

- New data indicator: Notifies whether it is HARQ initial transmission or retransmission.

- Redundancy version: Notifies the redundancy version of HARQ.

- Transmit Power Control (TPC) command for PUCCH (Physical Uplink Control CHannel): Notifies the transmit power control command for PUCCH, an uplink control channel.

The DCI goes through channel coding and modulation processes and is transmitted through a downlink physical control channel, PDCCH (Physical downlink control channel) or EPDCCH (Enhanced PDCCH).

In general, the DCI is independently channel coded for each terminal and then transmitted as an independent PDCCH. In the time domain, the PDCCH is mapped and transmitted during the control channel transmission period. The frequency domain mapping position of the PDCCH is determined by the identifier (ID) of each terminal and is spread over the entire system transmission band.

Downlink data is transmitted through PDSCH (Physical Downlink Shared Channel), a physical channel for downlink data transmission. The PDSCH is transmitted after the control channel transmission section, and scheduling information such as specific mapping position and modulation method in the frequency domain is provided by the DCI transmitted through the PDCCH.

Through the MCS, which consists of 5 bits among the control information constituting the DCI, the base station notifies the terminal of the modulation method applied to the PDSCH to be transmitted and the size of the data to be transmitted (transport block size; TBS). The TBS corresponds to the size before channel coding for error correction is applied to the data (transport block, TB) that the base station wants to transmit.

The modulation methods supported by the LTE system are QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), and 64QAM, and each modulation order (Qm) corresponds to 2, 4, and 6. That is, 2 bits per symbol can be transmitted for QPSK modulation, 4 bits per symbol for 16QAM modulation, and 6 bits per symbol for 64QAM modulation.

Bandwidth expansion technology was adopted in 3GPP LTE Rel-10 to support higher data transmission volume compared to LTE Rel-8. This technology, called bandwidth extension or carrier aggregation (CA), expands the band and can increase the amount of data transmission by the expanded band compared to LTE Rel-8 terminals that transmit data in one band. . Each of the above bands is called a component carrier (CC), and an LTE Rel-8 terminal is specified to have one component carrier each for downlink and uplink. In addition, the downstream configuration carrier and the uplink configuration carrier connected to SIB-2 are collectively called a cell. The SIB-2 connection relationship between the downstream configuration carrier and the uplink configuration carrier is transmitted as a system signal or a higher level signal. A terminal supporting CA can receive downlink data and transmit uplink data through multiple serving cells.

In Rel-10, when it is difficult for the base station to send a PDCCH (Physical Downlink Control Channel) to a specific UE from a specific serving cell, it transmits the PDCCH from another serving cell and the PDCCH is transmitted to the PDSCH (Physical Downlink Shared Channel) of the other serving cell. The Carrier Indicator Field (CIF) can be set as a field indicating that it indicates PUSCH (Physical Uplink Shared Channel). CIF can be set to a terminal that supports CA. CIF was decided to allow a specific serving cell to indicate another serving cell by adding 3 bits to the PDCCH information. CIF is included only when doing cross carrier scheduling, and when CIF is not included, cross carrier scheduling is performed. do not perform When the CIF is included in the downlink assignment information (DL assignment), the CIF indicates a serving cell where the PDSCH scheduled by the DL assignment will be transmitted, and the CIF is included in the uplink resource allocation information (UL grant) When present, the CIF is defined to indicate the serving cell where the PUSCH scheduled by the UL grant will be transmitted.

As mentioned above, in LTE-10, carrier aggregation (CA), a bandwidth expansion technology, is defined, and multiple serving cells can be configured for the terminal. And the terminal periodically or aperiodically transmits channel information about the plurality of serving cells to the base station for data scheduling of the base station. The base station schedules and transmits data for each carrier, and the terminal transmits A/N feedback for the data transmitted for each carrier. LTE Rel-10 is designed to transmit A/N feedback of up to 21 bits, and when the transmission of A/N feedback and channel information overlaps in one subframe, it is designed to transmit A/N feedback and discard the channel information. . In LTE Rel-11, the channel information of one cell is multiplexed along with the A/N feedback, and the A/N feedback of up to 22 bits and the channel information of one cell are designed to be transmitted in PUCCH format 3 from the transmission resources of PUCCH format 3. did.

In LTE-13, a scenario of setting up to 32 serving cells is assumed, and the concept of expanding the number of serving cells up to 32 has been completed by using not only the licensed band but also the unlicensed band. In addition, considering that the number of licensed bands such as LTE frequencies is limited, the provision of LTE services in unlicensed bands such as the 5GHz band has been completed, and this is called LAA (Licensed Assisted Access). LAA applied carrier aggregation technology in LTE to support operation of LTE cells in the licensed band as P cells and LAA cells in the unlicensed band as S cells. Therefore, as in LTE, feedback occurring in the LAA cell, which is an S cell, must be transmitted only in the P cell, and the downlink subframe and uplink subframe can be freely applied to the LAA cell. Unless otherwise stated in this specification, LTE shall refer to all evolved technologies of LTE such as LTE-A and LAA.

Meanwhile, New Radio Access Technology (NR), a post-LTE communication system, i.e. the 5th generation wireless cellular communication system (hereinafter referred to as 5G in this specification), can freely reflect various requirements of users and service providers. Therefore, services that satisfy various requirements can be supported.

Therefore, 5G includes enhanced mobile broadband communication (eMBB: Enhanced Mobile BroadBand, hereinafter referred to as eMBB), massive machine type communication (mMTC: Massive Machine Type Communication, hereinafter referred to as mMTC), Various 5G services such as Ultra Reliable and Low Latency Communications (URLLC, hereinafter referred to as URLLC) are provided with a maximum terminal transmission speed of 20Gbps, a maximum terminal speed of 500km/h, and a maximum delay time of 0.5ms. It can be defined as a technology to satisfy the requirements selected for each 5G service among requirements such as , terminal connection density of 1,000,000 terminals/km2, etc.

For example, in order to provide eMBB in 5G, from the perspective of one base station, it must be able to provide a maximum terminal transmission rate of 20Gbps in the downlink and a maximum terminal transmission rate of 10Gbps in the uplink. At the same time, the average transmission speed that the terminal can actually experience must be increased. In order to meet these requirements, improvements in transmission and reception technology are required, including more advanced multiple-input multiple output transmission technology.

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G. In order to efficiently provide the Internet of Things, mMTC requires the following requirements: support for access to a large number of terminals within a cell, improved coverage of terminals, improved battery time, and reduced terminal costs. Since the Internet of Things provides communication functions by attaching various sensors and various devices, it must be able to support a large number of terminals (for example, 1,000,000 terminals/km2) within a cell. Additionally, due to the nature of the service, mMTC requires a wider coverage compared to the coverage provided by eMBB, as there is a high possibility that the terminal will be located in a shaded area, such as the basement of a building or an area not covered by cells. mMTC is likely to be composed of low-cost terminals, and since it is difficult to frequently replace the terminal's battery, a very long battery life time is required.

Lastly, in the case of URLLC, it is a cellular-based wireless communication used for specific purposes, as a service used for remote control of robots or mechanical devices, industrial automation, unmanned aerial vehicles, remote health control, emergency notification, etc. , communications that provide ultra-low latency and ultra-reliability must be provided. For example, URLLC has a requirement to satisfy a maximum delay time of less than 0.5 ms and at the same time provide a packet error rate of less than 10-5. Therefore, for URLLC, a smaller Transmit Time Interval (TTI) must be provided than 5G services such as eMBB, and at the same time, design requirements that allocate wide resources in the frequency band are required.

The services considered in the 5th generation wireless cellular communication system described above must be provided as one framework. In other words, for efficient resource management and control, it is desirable for each service to be integrated, controlled, and transmitted as a single system rather than operating independently.

FIG. 1B is a diagram illustrating an example in which services considered in 5G are multiplexed and transmitted in one system.

In FIG. 1B, the frequency-time resource (1b-01) used by 5G may be composed of a frequency axis (1b-02) and a time axis (1b-03). Figure 1b illustrates that eMBB (1b-05), mMTC (1b-06), and URLLC (1b-07) are operated by a 5G base station within a 5G framework. Additionally, as a service that can be additionally considered in 5G, enhanced Mobile Broadcast/Multicast Service (eMBMS, 1b-08) to provide broadcasting services on a cellular basis can also be considered. Services considered in 5G, such as eMBB (1b-05), mMTC (1b-06), URLLC (1b-07), and eMBMS (1b-08), use time division multiplexing (Time Division Multiplexing) within the frequency bandwidth of one system operating in 5G. -It can be multiplexed and transmitted through Division Multiplexing (TDM) or Frequency Division Multiplexing (FDM), and spatial division multiplexing (Spatial Division Multiplexing) can also be considered. In the case of eMBB (1b-05), it is desirable to transmit by occupying the maximum frequency bandwidth at a certain random time in order to provide the increased data transmission rate described above. Therefore, in the case of the eMBB (1b-05) service, it is desirable to transmit in TDM within the transmission bandwidth of other services and the system (1b-01). However, depending on the needs of other services, it is transmitted through FDM within the transmission bandwidth of other services and the system. It is also desirable to be

In the case of mMTC (1b-06), unlike other services, an increased transmission section is required to secure wide coverage, and coverage can be secured by repeatedly transmitting the same packet within the transmission section. At the same time, in order to reduce terminal complexity and terminal price, there is a limit to the transmission bandwidth that the terminal can receive. Considering these requirements, it is desirable that mMTC (1b-06) be transmitted by FDM with other services within the 5G transmission system bandwidth (1b-01).

It is desirable for the URLLC (1b-07) to have a short Transmit Time Interval (TTI) compared to other services in order to satisfy the ultra-delay requirements required by the service. At the same time, in order to satisfy ultra-reliability requirements, it must have a low coding rate, so it is desirable to have a wide bandwidth in terms of frequency. Considering the requirements of URLLC (1b-07), it is desirable that URLLC (1b-07) be TDM with other services within the 5G transmission system bandwidth (1b-01).

In the above, the need for various services to satisfy various requirements in 5G is described, and the requirements for services that are representatively being considered are described.

Meanwhile, in 5G, even if services and technologies for 5G phase 2 or beyond 5G are multiplexed on the 5G operating frequency, 5G phase 2 or beyond 5G technologies and services will be provided so that there are no backward compatibility problems in the operation of previous 5G technologies. There are requirements that must be met to enable this. The above requirement is called forward compatibility, and technologies to satisfy future compatibility should be considered when designing early 5G. Because there was insufficient consideration for future compatibility in the initial LTE standardization stage, limitations may arise in providing new services within the LTE framework. For example, in the case of eMTC (enhanced Machine Type Communication) applied in LTE release-13, in order to reduce the cost of the terminal by reducing the complexity of the terminal, the system bandwidth provided by the serving cell is increased. Regardless, communication is only possible at a frequency corresponding to 1.4 MHz. Therefore, a terminal supporting eMTC cannot receive the Physical Downlink Control Channel (PDCCH) transmitted in all bands of the existing system transmission bandwidth, so the signal is not transmitted in the time interval in which the PDCCH is transmitted. A restriction has occurred that prevents reception. Therefore, the 5G communication system must be designed so that the services considered after the 5G communication system coexist and operate efficiently with the 5G communication system. For future compatibility in the 5G communication system, resource resources must be freely allocated and transmitted so that services to be considered in the future can be freely transmitted in the time-frequency resource area supported by the 5G communication system.

Each of the services described above may have different transmission/reception techniques and transmission/reception parameters to satisfy the requirements of each service. For example, each service may have a different Numerology depending on each service requirement. Here, numerology refers to the Cyclic Prefix (CP) length and subcarrier spacing in a communication system based on Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA). spacing), OFDM symbol length, transmission time interval length (TTI), etc. As an example of different numerologies between the above services, eMBMS (1b-08) may have a longer CP length than other services. Since eMBMS (1b-08) transmits broadcast-based upper level traffic, the same data can be transmitted in all cells. At this time, from the UE's perspective, if signals received from a plurality of cells arrive within the CP length, the UE can receive and decode all of these signals, thereby obtaining a single frequency network diversity (SFN) gain. Therefore, there is an advantage that even terminals located at the cell border can receive broadcast information without coverage restrictions. However, when supporting eMBMS in 5G, if the CP length is relatively long compared to other services, waste due to CP overhead occurs, and at the same time, a longer OFDM symbol length is required compared to other services, which is at the same time longer than other services. A narrow subcarrier spacing is required.

Additionally, as an example of different numerology being used between services in 5G, in the case of URLLC, a shorter OFDM symbol length may be required as a smaller TTI is required compared to other services, and at the same time, a wider subcarrier spacing may be required.

Meanwhile, the frequencies at which 5G is considered to operate range from several GHz to tens of GHz. In the low frequency band of several GHz, FDD (Frequency Division Duplex) is preferred over TDD (Time Division Duplex), and in the high frequency band of several tens of GHz, FDD (Frequency Division Duplex) is preferred. TDD is considered more suitable than FDD. When multiplexing various 5G services within one TDD carrier, services with different transmission time intervals (Transmission Time Interval, or Transmit Time Interval) may require different frame structures (i.e., uplink or downlink frames), There is a need for a method for the base station to multiplex services in the different transmission time sections and for the terminal to decode the services transmitted to the terminal in each transmission time section.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. At this time, it should be noted that in the attached drawings, identical components are indicated by identical symbols whenever possible. Additionally, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted.

In addition, in describing the embodiments of the present invention in detail, the main target will be LTE and 5G systems, but the main gist of the present invention is that the scope of the present invention is largely extended to other communication systems with similar technical background and channel types. It can be applied with slight modifications without departing from the scope, and this may be possible at the discretion of a person skilled in the technical field of the present invention.

In the following, we will describe a 5G communication system in which 5G cells operate as a stand-alone, or a 5G communication system in which 5G cells operate in a non-stand alone manner by combining them with other stand-alone 5G cells through dual connectivity or carrier aggregation.

1C and 1D are diagrams showing a 1-1 embodiment and a 1-2 embodiment of a communication system to which the present invention is applied. The methods proposed in the present invention can be applied to both the system of FIG. 1C and the system of FIG. 1D.

Referring to FIG. 1C, the top diagram of FIG. 1C shows a case where a 5G cell (1c-02) operates stand-alone within one base station (1c-01) in a network. The terminal (1c-04) is a 5G capable terminal that has a 5G transmission/reception module. The terminal (1c-04) acquires synchronization through a synchronization signal transmitted from the 5G stand-alone cell (1c-01), and after receiving system information, attempts random access to the 5G base station (1c-01). The terminal (1c-04) transmits and receives data through the 5G cell (1c-02) after the RRC connection with the 5G base station (1c-01) is completed. In this case, there are no restrictions on the duplex method of the 5G cell (1c-02). In the system shown at the top of FIG. 1C, a 5G cell may be equipped with a plurality of serving cells.

Next, the bottom diagram of FIG. 1C shows the installation of a 5G stand-alone base station (1c-11) and a 5G non-stand alone base station (1c-12) to increase data transmission. The terminal (1c-14) is a 5G capable terminal that has a 5G transmission and reception module to perform 5G communication at multiple base stations. The 5G capable terminal may be a terminal that supports only one 5G service, or may be a terminal that supports multiple 5G services. A terminal that supports only one 5G service above can support one numerology, and a terminal that supports multiple 5G services can support multiple numerologies. The terminal (1c-14) acquires synchronization through the synchronization signal transmitted from the 5G stand-alone base station (1c-11), and after receiving system information, provides random access to the 5G stand-alone base station (1c-11). Try it. After the RRC connection with the 5G stand-alone base station (1c-11) is completed, the terminal (1c-14) additionally sets up a 5G non-stand alone cell (1c-15) and uses the 5G stand-alone base station (1c-11) as above. 11) Alternatively, data is transmitted and received through a 5G non-stand alone base station (1c-12). In this case, there are no restrictions on the duplex method of the 5G stand-alone base station (1c-11) or the 5G non-stand alone base station (1c-12), and the 5G stand-alone base station (1c-11) and the 5G non-stand alone base station (1c-12) It is assumed that the base station 1c-12 is connected to an ideal backhaul network or a non-ideal backhaul network. Therefore, with an ideal backhaul network (1c-13), fast X2 communication (1c-13) between base stations is possible. In the system shown at the bottom of FIG. 1C, a 5G cell may be equipped with a plurality of serving cells.

Next, referring to FIG. 1D, the upper diagram of FIG. 1D shows a case where an LTE cell (1d-02) and a 5G cell (1d-03) coexist within one base station (1d-01) in a network. . The terminal (1d-04) may be an LTE capable terminal with an LTE transmission/reception module, a 5G capable terminal with a 5G transmission/reception module, or a terminal simultaneously with an LTE transmission/reception module/5G transmission/reception module. A 5G capable terminal having the 5G transmission/reception module may be a terminal that supports only one 5G service or may be a terminal that supports multiple 5G services. A terminal that supports only one 5G service above can support one numerology, and a terminal that supports multiple 5G services can support multiple numerologies. The terminal (1d-04) acquires synchronization through a synchronization signal transmitted from the LTE cell (1d-02) or 5G cell (1d-03), and after receiving system information, the base station (1d-01) and the LTE cell Data is transmitted and received through (1d-02) or 5G cell (1d-03). In this case, there are no restrictions on the duplex method of the LTE cell (1d-02) or 5G cell (1d-03). Uplink control transmission is transmitted through the LTE cell (1d-02) when the LTE cell is a P cell, and through the 5G cell (1d-03) when the 5G cell is a P cell. In the system shown at the top of FIG. 1D, the LTE cell and the 5G cell can have a plurality of serving cells, and a total of 32 serving cells can be supported. In the network, the base station (1d-01) is assumed to be equipped with both an LTE transmission and reception module (system) and a 5G transmission and reception module (system), and the base station (1d-01) manages the LTE system and the 5G system in real time. It is possible to operate. For example, when time resources are divided and the LTE system and 5G system are operated at different times, it is possible to dynamically select the allocation of time resources for the LTE system and 5G system. The terminal (1d-04) receives resources (time resources, frequency resources, antenna resources, space resources, etc.) operated separately by the LTE cell and the 5G cell from the LTE cell (1d-02) or the 5G cell (1d-03). By receiving a signal indicating allocation, it is possible to know through which resources data is received from the LTE cell (1d-02) and the 5G cell (1d-03).

Next, the bottom diagram of FIG. 1D shows the installation of an LTE macro base station (1d-11) for wide coverage in the network and a 5G small base station (1d-12) for increasing data transmission. The terminal (1d-14) may be an LTE capable terminal with an LTE transmission/reception module, a 5G capable terminal with a 5G transmission/reception module, or a terminal simultaneously with an LTE transmission/reception module/5G transmission/reception module. A 5G capable terminal having the 5G transmission/reception module may be a terminal that supports only one 5G service or may be a terminal that supports multiple 5G services. A terminal that supports only one 5G service above can support one numerology, and a terminal that supports multiple 5G services can support multiple numerologies. The terminal (1d-14) acquires synchronization through a synchronization signal transmitted from the LTE base station (1d-11) or the 5G base station (1d-12), and after receiving system information, connects the LTE base station (1d-11) and the 5G Data is transmitted and received through the base station (1d-12). In this case, there are no restrictions on the duplex method of the LTE macro base station (1d-11) or 5G small base station (1d-12). Uplink control transmission is transmitted through the LTE cell (1d-11) when the LTE cell is a P cell, and through the 5G cell (1d-12) when the 5G cell is a P cell. At this time, it is assumed that the LTE base station (1d-11) and the 5G base station (1d-12) have an ideal backhaul network or a non-ideal backhaul network. Therefore, with an ideal backhaul network (1d-13), fast inter-base station It is possible for the 5G base station 1d-12 to receive related control information in real time from the LTE base station 1d-11. In the system shown in the lower drawing of 1d above, LTE cells and 5G cells can have multiple serving cells, and a total of 32 serving cells can be supported. The base station (1d-11 or 1d-12) is capable of managing and operating the LTE system and 5G system in real time. For example, if the base station (1d-11) divides resources in time and operates the LTE system and 5G system at different times, the allocation of time resources of the LTE system and 5G system is dynamically selected and the signal is transmitted to It is possible to transmit to 1d-12). The terminal (1d-14) receives resources (time resources, frequency resources, antenna resources, space resources, etc.) operated separately by the LTE cell and the 5G cell from the LTE base station (1d-11) or the 5G base station (1d-12). By receiving a signal indicating allocation, it is possible to know through which resources data is transmitted and received from the LTE cell (1d-11) and the 5G cell (1d-12).

Meanwhile, if the LTE base station (1d-11) and the 5G base station (1d-12) have a non-ideal backhaul network (1d-13), fast inter-base station X2 communication (1d-13) is impossible. Therefore, the base station (1d-11 or 1d-12) is capable of operating the LTE system and 5G system semi-statically. For example, when the base station (1d-11) divides resources in time and operates the LTE system and 5G system at different times, it selects the allocation of time resources for the LTE system and the 5G system and sends the signal to X2 in advance to the other base station (base station) By transmitting to 1d-12), it is possible to distinguish resources between the LTE system and the 5G system. The terminal (1d-14) receives resources (time resources, frequency resources, antenna resources, space resources, etc.) operated separately by the LTE cell and the 5G cell from the LTE base station (1d-11) or the 5G base station (1d-12). By receiving a signal indicating allocation, it is possible to know through which resources data is transmitted and received from the LTE cell (1d-11) and the 5G cell (1d-12).

Next, Figure 1e is a diagram showing subframe structures proposed in the present invention. Let us explain the subframe structures in the transmission time section that various services can have in the 5G communication system through the upper and lower drawings of FIG. 1E.

In the upper and lower figures of Figure 1e, X1 (1e-11) and Frame structures 1e-12 to 1e-17 and 1e-22 to 1e-27 are shown. For example, X1 may be 1ms, X2 may be 0.5ms, and X1 and , …….) can also be used by multiplexing various transmission time sections. In the present invention, the unit of signals transmitted in one transmission time interval is referred to as a subframe, and a subframe includes at least one downlink symbol (1e-01), guard symbol (1e-01), or uplink symbol (1e-03). It consists of: When OFDM of the symbol is used, it may be defined as an OFDM symbol, and the length of the OFDM symbol may vary depending on the number of subcarriers, CP length, and bandwidth size.

Subframes (1e-12 to 1e-17) are indicated to the terminal by the base station, and the terminal receives information related to the subframes (1e-12 to 1e-17), that is, when and which subframe, through a higher signal or physical signal. Obtains whether a frame is used. The location and number of each subframe (1e-12 to 1e-17) may be set in advance by a higher level signal so that the terminal can obtain related information, and each subframe or from the previous subframe to the next subframe may be changed by a physical signal. The terminal may acquire the type.

First, let's explain the downlink symbol (1e-01), protection symbol (1e-02), or uplink symbol (1e-03), which are the components that make up each subframe.

Each subframe consists of at least one downlink symbol (1e-01), protection symbol (1e-02), or uplink symbol (1e-03), and the downlink symbol (1e-01) contains downlink control information and downlink data. Used for transmission. The protection symbol (1e-02) guarantees the RF switching time of the terminal or base station when the symbols on both sides of the protection symbol are in different directions (i.e. upward and downward) within one subframe or when considering two subframes successively. , It is used to absorb delay time due to the distance between the terminal and the base station within the protection symbol (1e-02). It is also used to ensure the processing time of a terminal that has the capability to receive downlink data and transmit uplink control information for the downlink data within one subframe. The number of protection symbols (1e-02) in one subframe is preset by the base station in consideration of the RF switching times and cell radius of the terminal in the cell, and the terminal can access the protection symbols in the subframe through the upper signal. Information on the number can be obtained from the base station. The uplink symbol (1e-03) is used for uplink control information and uplink data transmission. The number of uplink symbols (1e-03) within one subframe is preset by the base station in consideration of uplink control information by cell radius and coverage of uplink data transmission, etc., and the terminal can use uplink symbols within one subframe through the upper signal. Information about the number of can be obtained from the base station.

Next, the structure of each subframe corresponding to the transmission time interval X1 (1e-11) is as follows.

The subframe (1e-12) consists only of downlink symbols (1e-01).

The subframe (1e-13) consists of a downlink symbol (1e-01) and a protection symbol (1e-02).

The subframe (1e-14) consists of a downlink symbol (1e-01), a protection symbol (1e-02), and an uplink symbol (1e-03). The subframe (1e-14) has a subframe structure capable of receiving downlink control information and downlink data and transmitting uplink control information for the downlink data within the same subframe.

The subframe (1e-15) consists of a downlink symbol (1e-01), a protection symbol (1e-02), and an uplink symbol (1e-03). The subframe 1e-15 has a subframe structure capable of receiving downlink control information and transmitting uplink data indicated by the downlink control information within the same subframe.

The subframe (1e-16) consists of a protection symbol (1e-02) and an uplink symbol (1e-03).

The subframe (1e-17) consists only of uplink symbols (1e-03).

Next, the structure of each subframe corresponding to the transmission time interval X2 (1e-21) is as follows.

The subframe (1e-22) consists only of downlink symbols (1e-01).

The subframe (1e-23) consists of a downlink symbol (1e-01) and a protection symbol (1e-02).

The subframe (1e-24) consists of a downlink symbol (1e-01), a protection symbol (1e-02), and an uplink symbol (1e-03). The subframe 1e-24 has a subframe structure capable of receiving downlink control information and downlink data and transmitting uplink control information for the downlink data within the same subframe.

The subframe (1e-25) consists of a downlink symbol (1e-01), a protection symbol (1e-02), and an uplink symbol (1e-03). The subframe 1e-25 has a subframe structure capable of receiving downlink control information and transmitting uplink data indicated by the downlink control information within the same subframe.

The subframe (1e-26) consists of a protection symbol (1e-02) and an uplink symbol (1e-03).

The subframe (1e-27) consists only of uplink symbols (1e-03).

Next, the issues that arise when multiplexing various transmission time sections within one carrier will be explained through Figure 1f.

Figure 1f is a diagram showing the situation to be solved by the present invention.

In Figure 1f, a subframe (1f-21) by the transmission time interval X1 (1f-11) and a subframe (1f-21) by 1f-22) shows a situation where they are mixed and multiplexed within one carrier, especially the TDD carrier.

The subframe by the transmission time interval X1 (1f-11) is composed of a downlink symbol, a protection symbol, and an uplink symbol, and the subframe by there is. In the example of FIG. 1F, since X1 has twice the length of X2, it can be seen that the subframe length by X1 corresponds to the length of two subframes by X2.

At this time, the downlink symbol of the subframe (1f-21) composed by X1 collides in time with the upstream symbol in the subframes (1f-22) composed by X2 (1f-23). In other words, the reception of the downstream data of the terminal served by X1 and the transmission of the upstream data of the terminal served by X2 must occur at the same time. In this case, the downstream data reception of the terminal served by X1 may be interfered with by the uplink data transmission of the terminal served by must be performed simultaneously. A method is needed to avoid problems such as the above interference problem and hardware complexity for simultaneous two-way data transmission and reception by the base station. The present invention proposes a method for solving the above issues and a method for multiplexing various transmission time sections.

Figure 1g is a diagram showing the 1-1 embodiment proposed by the present invention.

First, the subframe structure is informed through the common transmission time section and the dedicated transmission time section through the drawings at the top and middle of Figure 1g, and the transmission of control information and data according to the subframe structure in the dedicated transmission time section is explained. do.

At the top of Figure 1g, a common transmission time section (1g-11) and a dedicated transmission time section (1g-12) are set, respectively. The common transmission time interval (1g-11) is used to determine the subframe structure to be used by all terminals within the base station and cell within the common transmission time interval (1g-11). The subframe structure may be preset for a certain period of time and instructed to the terminal. In this case, the subframe structure may be transmitted through a higher-order signal including a system signal and an RRC signal. The subframe structure may change in each common transmission time interval and be indicated to the terminal. In this case, the subframe structure may be transmitted through a physical signal. When a physical signal is transmitted, a decoding operation of the terminal to find the subframe structure may be performed according to the common transmission time interval (1g-11). For example, the current subframe structure or the subframe structure for the next common transmission time interval can be determined through control information transmission in the first symbol where the common transmission time interval (1g-11) begins, and the terminal can determine the subframe structure for each common transmission time interval. The subframe structure can be obtained through control information decoding from the first symbol where (1g-11) begins. The subframe structure includes the subframe structure described in FIG. 1E. The dedicated transmission time section (1g-12) is a transmission time section for transmitting control information and data information to the terminal, and it is possible to set a dedicated transmission time section (1g-12) with a different length for each service. . For example, in 1g-21, the dedicated transmission time section (1g-12) has a length corresponding to half of the common transmission time section (1g-11), and control information including subframe structure information and control information according to the length. Data information scheduled by is transmitted. Alternatively, in 1g-22, the dedicated transmission time section (1g-13) has a length corresponding to the common transmission time section (1g-11), and is scheduled by control information and control information including subframe structure information according to the length. The data information is transmitted.

Let us look at an example in which the base station and the terminal are operated with the common transmission time section and the dedicated transmission time section defined differently from the top of FIG. 1g through the interruption of FIG. 1g. In Figure 1g, a common transmission time section (1g-31) and a dedicated transmission time section (1g-32) are set, respectively. In the middle of Figure 1g, the common transmission time section (1g-31) may mean the period in which the terminal must attempt decoding to find the location where the subframe structure used in the dedicated transmission time section begins. The subframe structure can be changed in each dedicated transmission time interval and indicated to the terminal. In this case, the subframe structure can be transmitted through a physical signal. When a physical signal is transmitted, a decoding operation of the terminal may be performed to find the location where the subframe structure begins according to the common transmission time interval (1g-11). For example, the start position of the current subframe structure or the subframe structure for the next common transmission time interval can be determined through control information transmission at the first symbol where the common transmission time interval (1g-32) begins, and the terminal can transmit each common transmission time interval. The position where the subframe structure of the dedicated transmission time section starts can be obtained through control information decoding from the first symbol where the transmission time section (1g-32) begins. The subframe structure includes the subframe structure described in FIG. 1E. The dedicated transmission time section (1g-31) is a transmission time section for transmitting control information and data information to the terminal, and it is possible to set a dedicated transmission time section (1g-31) with a different length for each service. . For example, in 1g-41, the dedicated transmission time section (1g-31) has a length that is twice the length of the common transmission time section (1g-32), and control information including subframe structure information and control according to the length. Data information scheduled by the information is transmitted.

The procedures of the base station and the terminal for the method described in the drawing at the top of FIG. 1g will be explained through the flowchart at the bottom of FIG. 1g.

First, the base station procedure according to the 1-1 embodiment of the present invention will be described.

In step 1g-50, the base station transmits transmission time interval setting information to the terminal. The transmission time section setting information includes information related to the common transmission time section and the dedicated transmission time section as described at the top of FIG. 1g, and the setting information includes a system signal, a higher level signal including an RRC signal, or a physical signal. is transmitted to the terminal through Additionally, the subframe structure may be determined in advance for a certain period of time and transmitted to the terminal through a system signal, an upper signal including an RRC signal, or a physical signal.

In step 1g-51, the base station transmits control information including data scheduling information for 5G service to the terminal. The control information may include a subframe structure according to a common transmission time interval. The control information may be a subframe structure for the current common transmission time section or the next common transmission time section. The control information may be transmitted in the first symbol of the subframe. Additionally, the data scheduling information includes all services considered for 5G as described in the present invention, and the data scheduling information includes frequency resources or time resources for data transmission of the 5G service. The data scheduling information may be transmitted by a higher-order signal or a physical signal.

In step 1g-52, the base station transmits and receives data to the terminal according to control information for 5G service. The control information may include a subframe structure as described in step 1g-51, and in this case, the base station transmits and receives data according to the subframe structure.

Next, the terminal procedure according to the 1-1 embodiment of the present invention will be described.

In step 1g-60, the terminal receives transmission time interval setting information from the base station. The transmission time section setting information includes information related to the common transmission time section and the dedicated transmission time section as described at the top of FIG. 1g, and the setting information includes a system signal, a higher level signal including an RRC signal, or a physical signal. is transmitted to the terminal through Additionally, the subframe structure may be determined in advance for a certain period of time and transmitted to the terminal through a system signal, an upper signal including an RRC signal, or a physical signal.

In step 1g-61, the terminal attempts to receive control information including data scheduling information for 5G service from the base station. The control information may include a subframe structure according to a common transmission time interval. The control information may be a subframe structure for the current common transmission time section or the next common transmission time section. The control information may be transmitted in the first symbol of a subframe. Additionally, the data scheduling information includes all services considered for 5G as described in the present invention, and the data scheduling information includes frequency resources or time resources for data transmission of the 5G service. The data scheduling information may be transmitted by a higher-order signal or a physical signal.

In step 1g-62, the terminal transmits and receives data to the base station according to control information for 5G service. The control information may include a subframe structure as described in step 1g-61, and in this case, the terminal transmits and receives data according to the subframe structure.

Figure 1h is a diagram showing the first and second embodiments proposed by the present invention.

First, when informing the subframe structure in the common transmission time section through the top of Figure 1h, if the first symbol of the subframe has an uplink symbol that cannot transmit downlink control information, the next subframe structure is established based on the previous subframe structure. Have them explain what they are looking for.

At the top of Figure 1h, a common transmission time section (1h-11 or 1h-12) is set, and thus a subframe structure with the length of the common transmission time section is determined. If the subframe structure starting with a downlink symbol in the previous common transmission time section (1h-11) is determined and transmitted to the terminal, and the subframe structure in the next common transmission time section (1h-12) starts with an uplink symbol , control information informing the terminal of the subframe structure starting with the uplink symbol cannot be transmitted. In this case, the subframe structure transmitted in the next common transmission time interval (1h-12) can be determined based on the subframe structure transmitted in the previous common transmission time interval (1h-11).

For example, in 1h-21, if the subframe structure transmitted in the previous common transmission time section (1h-11) consists only of downlink symbols, the subframe structure transmitted in the next common transmission time section (1h-12) consists of downlink and uplink symbols. It must begin with a protection symbol in between. Therefore, even if the terminal attempts to decode the downlink control information including the subframe structure (1h-31), if it fails to obtain the downlink control information, it can be seen that it has an uplink subframe structure consisting of a protection symbol and an uplink symbol.

In addition, in 1h-22, if the subframe structure transmitted in the previous common transmission time section (1h-11) consists of a downlink symbol and a guard symbol, the subframe structure transmitted in the next common transmission time section (1h-12) is an uplink symbol. It must be a subframe structure that starts with a symbol. Therefore, even if the terminal attempts to decode the downlink control information including the subframe structure (1h-32), if it fails to obtain the downlink control information, it can be seen that it has an uplink subframe structure consisting of only uplink symbols.

In addition, if the subframe structure transmitted in the previous common transmission time interval (1h-11) in 1h-23 consists of a downlink symbol, a protection symbol, and an uplink symbol, the subframe transmitted in the next common transmission time interval (1h-12) The structure must be a subframe structure starting with an upward symbol. Therefore, even if the terminal attempts to decode the downlink control information including the subframe structure (1h-33), if it fails to obtain the downlink control information, it can be seen that it has an uplink subframe structure consisting of only uplink symbols.

In addition, if the subframe structure transmitted in the previous common transmission time interval (1h-11) in 1h-24 consists of a downlink symbol, a protection symbol, and an uplink symbol, the subframe transmitted in the next common transmission time interval (1h-12) The structure must be a subframe structure starting with an upward symbol. Therefore, even if the terminal attempts to decode the downlink control information including the subframe structure (1h-34), if it fails to obtain the downlink control information, it can be seen that it has an uplink subframe structure consisting of only uplink symbols.

The terminal procedures for the method described in the drawing at the top of FIG. 1H will be explained through the flowchart at the bottom of FIG. 1H.

Let us now describe the terminal procedure according to the first and second embodiments of the present invention.

In step 1h-60, the terminal acquires a subframe structure starting with a downlink symbol from the base station in transmission time interval n. The subframe structure starting with a downlink symbol includes the subframe structure shown in FIG. 1E. The transmission time section setting information includes information related to the common transmission time section and the dedicated transmission time section as described at the top of FIG. 1g, and the setting information includes a system signal, a higher level signal including an RRC signal, or a physical signal. is transmitted to the terminal through Additionally, the subframe structure may be determined in advance for a certain period of time and transmitted to the terminal through a system signal, an upper signal including an RRC signal, or a physical signal.

In step 1h-61, the terminal attempts to receive downlink control information including the subframe structure from the base station in transmission time interval n+1. The control information may include a subframe structure according to a common transmission time interval. The control information may be a subframe structure for the current common transmission time section or the next common transmission time section. The control information may be transmitted in the first symbol of the subframe. If reception of the downlink control information is successful in step 1h-61, the terminal acquires a subframe structure of transmission time interval n+1 included in the downlink control information in step 1h-62.

If reception of downlink control information is not successful in step 1h-61, the terminal acquires the subframe structure of transmission time interval n+1 based on the subframe structure of transmission time interval n in step 1h-63. The specific method follows the method described through the upper drawing of FIG. 1h.

Figure 1i is a diagram showing embodiments 1-3 proposed in the present invention.

First, through the drawing at the top of FIG. 1i, the subframe structure is informed through the common transmission time section and the dedicated transmission time section, and data transmission according to the subframe structure is performed in the dedicated transmission time section, including whether the data is properly received. Let us explain transmitting upward feedback information.

The description of the common transmission time section (1i-11) and the dedicated transmission time section (1i-12) may follow what is explained in the upper and middle drawings of FIG. 1G.

Upward feedback information (1i-21) for data transmitted according to the subframe structure in the dedicated transmission time section and upward feedback information (1i-22) for data transmitted according to the subframe structure according to the length of the common transmission time section ) can be multiplexed at the same time.

A specific method for multiplexing is for the terminal to transmit each uplink control channel to transmit feedback on data transmitted in the different transmission time intervals. At this time, when the power of the terminal is not sufficient (power limited case), a method is used to protect feedback on data to be transmitted in the common transmission time section by first adjusting the power for feedback on data corresponding to the dedicated transmission time section. It can be applied.

Another method for multiplexing is for the terminal to transmit one uplink control channel to transmit feedback on data transmitted in the different transmission time intervals, and multiplex the information into a fixed length. If the terminal misses certain data, the base station does not know what data the terminal transmitted feedback for. Accordingly, the above problem can be solved by fixing the payload size of feedback for data transmitted in different transmission time intervals and fixing the position of the corresponding feedback.

The procedures of the base station and the terminal for the method described in the drawing at the top of FIG. 1I will be explained through the flow chart at the bottom of FIG. 1I.

First, the base station procedure according to the first to third embodiments of the present invention will be described.

In step 1i-50, the base station transmits transmission time interval setting information to the terminal. The transmission time section setting information includes information related to the common transmission time section and the dedicated transmission time section as described at the top of FIG. 1g, and the setting information includes a system signal, a higher level signal including an RRC signal, or a physical signal. is transmitted to the terminal through Additionally, the subframe structure may be determined in advance for a certain period of time and transmitted to the terminal through a system signal, an upper signal including an RRC signal, or a physical signal.

In step 1i-51, the base station transmits control information and data including data scheduling information for 5G service to the terminal. The control information may include a subframe structure according to a common transmission time interval. The control information may be a subframe structure for the current common transmission time section or the next common transmission time section. The control information may be transmitted in the first symbol of the subframe. Additionally, the data scheduling information includes all services considered for 5G as described in the present invention, and the data scheduling information includes frequency resources or time resources for data transmission of the 5G service. The data scheduling information may be transmitted by a higher-order signal or a physical signal. The base station transmits and receives data according to the subframe structure of the control information.

In step 1i-52, the base station receives feedback on the data transmitted in step 1j-51. The method of receiving feedback follows the method described in the upper drawing of FIG. 1i.

Next, the terminal procedure according to the first to third embodiments of the present invention will be described.

In step 1i-60, the terminal receives transmission time interval setting information from the base station. The transmission time section setting information includes information related to the common transmission time section and the dedicated transmission time section as described at the top of FIG. 1g, and the setting information includes a system signal, a higher level signal including an RRC signal, or a physical signal. is transmitted to the terminal through Additionally, the subframe structure may be determined in advance for a certain period of time and transmitted to the terminal through a system signal, an upper signal including an RRC signal, or a physical signal.

In step 1i-61, the terminal receives control information and data including data scheduling information for 5G service from the base station. The control information may include a subframe structure according to a common transmission time interval. The control information may be a subframe structure for the current common transmission time section or the next common transmission time section. The control information may be transmitted in the first symbol of the subframe. Additionally, the data scheduling information includes all services considered for 5G as described in the present invention, and the data scheduling information includes frequency resources or time resources for data transmission of the 5G service. The data scheduling information may be transmitted by a higher-order signal or a physical signal. The terminal transmits and receives data according to the subframe structure of the control information.

In step 1i-62, the terminal transmits feedback about the data received in step 1j-61. The feedback transmission method follows the method described in the upper diagram of FIG. 1i.

Figure 1j is a diagram showing a base station device according to the present invention.

The controller (1j-01) transmits control information and controls data transmission and reception according to the subframe structure according to FIG. 1E of the present invention, the embodiments of the present invention according to FIGS. 1G, 1H, and 1I, and the base station procedure, to use 5G resources. It is transmitted to the terminal through the information transmission device (1j-05), and the scheduler (1j-03) schedules 5G data from 5G resources and transmits and receives 5G data to the 5G terminal through the 5G data transmission and reception device (1j-07). .

Figure 1k is a diagram showing a terminal device according to the present invention.

Receiving control information and data from the base station through the 5G resource information receiving device (1k-05) according to the subframe structure according to Figure 1e of the present invention, the embodiments of the present invention according to Figures 1g, 1h, and 1i, and the terminal procedure. And, the controller (1k-01) transmits and receives 5G data scheduled in the allocated 5G resources to and from the 5G base station through the 5G data transmitting and receiving device (1k-06).

<Second Embodiment>

The present invention relates to a general wireless mobile communication system, and particularly to a wireless mobile communication system applying a multiple access scheme using a multi-carrier such as OFDMA: Orthogonal Frequency Division Multiple Access. This is about how to map signals.

The current mobile communication system is evolving from an initial voice-oriented service to a high-speed, high-quality wireless packet data communication system to provide data services and multimedia services. To this end, several standardization organizations such as 3GPP, 3GPP2, and IEEE are working on standards for the 3rd generation evolved mobile communication system that applies multiple access methods using multi-carriers. Recently, various mobile communication standards such as 3GPP's Long Term Evolution (LTE), 3GPP2's Ultra Mobile Broadband (UMB), and IEEE's 802.16m provide high-speed, high-quality wireless packet data transmission services based on multiple access methods using multi-carriers. was developed to support.

Existing 3rd generation evolved mobile communication systems such as LTE, UMB, and 802.16m are based on the multi-carrier multiple access method, and apply Multiple Input Multiple Output (MIMO, multiple antennas) to improve transmission efficiency and beam- It is characterized by using a variety of technologies such as beamforming, Adaptive Modulation and Coding (AMC) methods, and channel sensitive scheduling methods. The various technologies above improve transmission efficiency by concentrating transmission power transmitted from multiple antennas according to channel quality, controlling the amount of transmitted data, and selectively transmitting data to users with good channel quality. Improves system capacity performance. Since most of these techniques operate based on channel state information between the base station (eNB: evolved Node B, BS: Base Station) and the terminal (UE: User Equipment, MS: Mobile Station), the eNB or UE is connected to the base station and the terminal. It is necessary to measure the channel status between channels, and the Channel Status Indication reference signal (CSI-RS) is used in this case. The previously mentioned eNB refers to a downlink transmission and uplink reception device located in a certain location, and one eNB performs transmission and reception for a plurality of cells. In one mobile communication system, multiple eNBs are geographically distributed, and each eNB performs transmission and reception for multiple cells.

Existing 3rd and 4th generation mobile communication systems such as LTE/LTE-A utilize MIMO technology, which transmits using multiple transmitting and receiving antennas to increase data transmission rate and system capacity. The MIMO technology utilizes a plurality of transmitting and receiving antennas to spatially separate and transmit a plurality of information streams. In this way, spatially separating and transmitting multiple information streams is called spatial multiplexing. In general, how many information streams can be applied to spatial multiplexing depends on the number of antennas of the transmitter and receiver. In general, the number of information streams that spatial multiplexing can be applied to is referred to as the rank of the corresponding transmission. In the case of MIMO technology supported by standards up to LTE/LTE-A Release 11, spatial multiplexing is supported for 16 transmit antennas and 8 receive antennas, and a rank of up to 8 is supported.

In the case of NR (New Radio access technology), a 5th generation mobile communication system currently being discussed, the design goal of the system is to be able to support various services such as eMBB, mMTC, and URLLC mentioned above, and to achieve this goal, always transmit By minimizing the reference signal and allowing the reference signal to be transmitted aperiodically, time and frequency resources can be transmitted flexibly.

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

In the accompanying drawings, some components are exaggerated, omitted, or schematically shown. Additionally, the size of each component does not entirely reflect its actual size. In each drawing, identical or corresponding components are assigned the same reference numbers.

At this time, it will be understood that each block of the processing flow diagram diagrams and combinations of the flow diagram diagrams can be performed by computer program instructions. These computer program instructions can be mounted on a processor of a general-purpose computer, special-purpose computer, or other programmable data processing equipment, so that the instructions performed through the processor of the computer or other programmable data processing equipment are described in the flow chart block(s). It creates the means to perform functions. These computer program instructions may also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular manner, so that the computer-usable or computer-readable memory It is also possible to produce manufactured items containing instruction means that perform the functions described in the flowchart block(s). Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a process that is executed by the computer, thereby generating a process that is executed by the computer or other programmable data processing equipment. Instructions that perform processing equipment may also provide steps for executing the functions described in the flow diagram 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). Additionally, it should be noted that in some alternative execution examples it is possible for the functions mentioned in the blocks to occur out of order. For example, it is possible for two blocks shown in succession to be performed substantially at the same time, or it is possible for the blocks to be performed in reverse order depending on the corresponding function.

At this time, the term '~unit' used in this embodiment refers to software or hardware components such as FPGA or ASIC, and the '~unit' performs certain roles. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'. In addition, the components and 'parts' may be implemented to regenerate one or more CPUs within the device or secure multimedia card.

Hereinafter, in this specification, the NR system, the LTE (Long Term Evolution) system, and the LTE-A (LTE-Advanced) system are described as examples, but the present invention has no special additions or subtractions to other communication systems using licensed bands and unlicensed bands. It can be applied without.

Figure 2a shows radio resources of 1 subframe and 1 RB, which are the minimum units that can be scheduled in the downlink in the LTE/LTE-A system.

The radio resource shown in FIG. 2A consists of one subframe on the time axis and one RB on the frequency axis. These radio resources consist of 12 subcarriers in the frequency domain and 14 OFDM symbols in the time domain, giving a total of 168 unique frequencies and time positions. In LTE/LTE-A, each unique frequency and time position in FIG. 2A is called a resource element (RE).

A plurality of different types of signals as follows may be transmitted through the radio resource shown in FIG. 2A.

1. CRS (Cell Specific RS): A reference signal transmitted periodically for all terminals belonging to one cell and can be commonly used by multiple terminals.

2. DMRS (Demodulation Reference Signal): It is a reference signal transmitted for a specific terminal and is transmitted only when data is transmitted to the terminal. DMRS can consist of a total of 8 DMRS ports. In LTE/LTE-A, port 7 to port 14 corresponds to DMRS ports, and the ports maintain orthogonality using CDM or FDM to prevent interference with each other.

3. PDSCH (Physical Downlink Shared Channel): A data channel transmitted in the downlink, used by the base station to transmit traffic to the terminal, and transmitted using RE in the data region of FIG. 2 where no reference signal is transmitted.

4. CSI-RS (Channel Status Information Reference Signal): A reference signal transmitted for terminals belonging to one cell is used to measure the channel status. Multiple CSI-RSs can be transmitted to one cell.

5. Other control channels (PHICH, PCFICH, PDCCH): ACK/NACK transmission to provide control information necessary for the terminal to receive PDSCH or to operate HARQ for uplink data transmission

In addition to the above signal, in the LTE-A system, muting can be set so that CSI-RS transmitted by another base station can be received without interference by terminals in the corresponding cell. The muting can be applied at a location where CSI-RS can be transmitted, and the terminal generally receives traffic signals by skipping the corresponding radio resource. In the LTE-A system, muting is also called zero-power CSI-RS as another term. This is because, due to the nature of muting, it is applied to the location of the CSI-RS and no transmission power is transmitted.

In FIG. 2A, CSI-RS will be transmitted using some of the locations indicated by A, B, C, D, E, E, F, G, H, I, and J depending on the number of antennas transmitting CSI-RS. You can. Muting can also be applied to some of the positions indicated by A, B, C, D, E, E, F, G, H, I, and J. In particular, CSI-RS can be transmitted with 2, 4, or 8 REs depending on the number of transmitting antenna ports. If the number of antenna ports is 2, CSI-RS is transmitted in half of the specific pattern in FIG. 2a, if the number of antenna ports is 4, CSI-RS is transmitted in the entire specific pattern, and if the number of antenna ports is 8, two patterns are used. CSI-RS is transmitted. On the other hand, muting always consists of one pattern unit. In other words, muting can be applied to multiple patterns, but cannot be applied to only part of one pattern if the location does not overlap with the CSI-RS. However, it can only be applied to part of one pattern only when the location of the CSI-RS and the location of muting overlap. When CSI-RS for two antenna ports is transmitted, the CSI-RS transmits the signals of each antenna port from two REs connected on the time axis, and the signals of each antenna port are separated by orthogonal codes. Additionally, when CSI-RS for four antenna ports is transmitted, two more REs are used in addition to the CSI-RS for two antenna ports to transmit signals for two additional antenna ports in the same manner. The same applies when CSI-RS for 8 antenna ports is transmitted. In the case of CSI-RS supporting 12 and 16 antenna ports, it is achieved by combining 3 CSI-RS transmission positions for the existing 4 antenna ports or combining 2 CSI-RS transmission positions for 8 antenna ports.

In addition, the terminal can be allocated CSI-IM (or IMR, interference measurement resources) along with CSI-RS, and the resources of CSI-IM have the same resource structure and location as the CSI-RS that supports 4 ports. CSI-IM is a resource for a terminal that receives data from one or more base stations to accurately measure interference from adjacent base stations. For example, if you want to measure the amount of interference when a neighboring base station is transmitting data and the amount of interference when it is not transmitting, the base station configures a CSI-RS and two CSI-IM resources, and one CSI-IM is used by the neighboring base station. By always transmitting signals and the other CSI-IM prevents adjacent base stations from always transmitting signals, the amount of interference from adjacent base stations can be effectively measured.

Table 2a below shows the RRC field that configures the CSI-RS setting.

[Table 2a] RRC settings to support periodic CSI-RS within the CSI process

Settings for channel status reporting based on periodic CSI-RS within the CSI process can be classified into four types as shown in Table 2a. CSI-RS config is for setting the frequency and time location of CSI-RS RE. Here, how many ports the corresponding CSI-RS has is set by setting the number of antennas. Resource config sets the RE location within the RB, and Subframe config sets the period and offset of the subframe. Table 2b is a table for Resource config and Subframe config settings currently supported by LTE.

[Table 2b] Resource config and Subframe config settings

(a) Resource config settings

(b) Subframe config settings

The terminal can check the frequency and time location, period and offset through Table 2b above. Qcl-CRS-info sets quasi co-location information for CoMP. CSI-IM config is for setting the frequency and time location of CSI-IM to measure interference. Since CSI-IM is always set based on 4 ports, there is no need to set the number of antenna ports, and Resource config and Subframe config are set in the same way as CSI-RS. CQI report config exists to configure how to report the channel status using the corresponding CSI process. The settings include periodic channel status reporting settings, aperiodic channel status reporting settings, PMI/RI reporting settings, RI reference CSI process settings, and subframe pattern settings.

The subframe pattern is used to set a measurement subframe subset to support channel and interference measurement with temporally different characteristics in the channel and interference measurement received by the terminal. Measurement subframe subset was first introduced in eICIC (enhanced Inter-Cell Interference Coordination) to estimate by reflecting different interference characteristics of ABS (Almost Blank Subframe) and non-ABS general subframes. Afterwards, in order to measure different channel characteristics between a subframe that always operates in DL and a subframe that can dynamically switch from DL to UL in eIMTA (enhanced Interference Mitigation and Traffic Adaptation), two IMRs can be set and measured. It has developed into an improved form. Table 2c and Table 2d show the measurement subframe subset for eICIC and eIMTA support.

[Table 2c] Measurement subframe subset settings for eICIC

[Table 2d] Measurement subframe subset settings for eIMTA

The eICIC measurement subframe subset supported by LTE is set using csi-MeasSubframeSet1-r10 and csi-MeasSubframeSet2-r10. MeasSubframePattern-r10 referred to by the field is shown in Table 2e below.

[Table 2e] MeasSubframePattern

In the above field, it means subframe #0 starting from the MSB on the left. If it is 1, it indicates that it is included in the corresponding measurement subframe subset. Unlike the eICIC measurement subframe subset, which sets each subframe set through each field, the eIMTA measurement subframe set uses one field, with 0 indicating the first subframe set and 1 indicating the second subframe set. Therefore, in eICIC, the subframe may not be included in two subframe sets, but in the case of eIMTA subframe set, there is a difference in that it must always be included in one of the two subframe sets.

In addition, there is a PC, which indicates the power ratio between the PDSCH and CSI-RS RE required for the terminal to generate a channel status report, and a Codebook subset restriction that sets which codebook to use. PC and codebook subset restriction refers to the settings for each subframe subset by the p-C-AndCBSRList field, which includes two P-C-AndCBSR fields in Table 2g below in list form.

[Table 2f] p-C-AndCBSRList

[Table 2g] P-C-AndCBSR

The PC can be defined as in Equation 2a below, and can be a value between -8 and 15 dB.

[Equation 2a]

The base station can variably adjust the CSI-RS transmission power for various purposes such as improving channel estimation accuracy, and the terminal can determine how lower or higher the transmission power to be used for data transmission through the notified PC is compared to the transmission power used for channel estimation. Able to know. For the above reason, it is possible for the terminal to calculate an accurate CQI and report it to the base station even if the base station varies the CSI-RS transmission power.

Codebook subset restriction is a function that allows the base station to not report to the terminal the codepoints of the codebook supported by the standard depending on the number of CRS or CSI-RS ports of the base station. This codebook subset restriction can be set by the codebookSubsetRestriction field included in AntennaInfoDedicated in Table 2h below.

[Table 2h] AntennaInfoDedicated

The codebookSubsetRestriction field consists of a bitmap, and the size of the bitmap is equal to the number of code points of the corresponding codebook. Therefore, each bitmap represents each code point, and if the value is 1, the terminal can report the code point to the base station through PMI. If the value is 0, the terminal can report the code point to the base station as PMI. does not exist. For reference, MSB indicates a high precoder index and LSB indicates a low precoder index (for example, 0).

In a cellular system, the base station must transmit a reference signal to the terminal to measure the downlink channel status. In the case of 3GPP's LTE-A (Long Term Evolution Advanced) system, the terminal measures the channel status between the base station and itself using the CRS or Channel Status Information Reference Signal (CSI-RS) transmitted by the base station. do. The channel state basically requires several factors to be considered, including the amount of interference in the downlink. The amount of interference in the downlink includes interference signals and thermal noise generated by antennas belonging to adjacent base stations, and is important for the terminal to determine the downlink channel situation. For example, when a signal is transmitted from a base station with one transmitting antenna to a terminal with one receiving antenna, the terminal uses the reference signal received from the base station to determine the energy per symbol that can be received in the downlink and the section in which the corresponding symbol is received. At the same time, the amount of interference to be received must be determined and Es/Io determined. The determined Es/Io is converted to a data transmission rate or an equivalent value and notified to the base station in the form of a Channel Quality Indicator (CQI), so that the base station transmits to the terminal at a certain data transmission rate in the downlink. It allows you to decide whether to do it or not.

In the case of the LTE-A system, the terminal feeds back information about the downlink channel status to the base station so that it can be used for the base station's downlink scheduling. In other words, the terminal measures the reference signal transmitted by the base station in the downlink and feeds back the information extracted from it to the base station in the form defined in the LTE/LTE-A standard. There are three main types of information fed back by the terminal in LTE/LTE-A.

● Rank Indicator (RI): The number of spatial layers that the terminal can receive in the current channel state.

● Precoder Matrix Indicator (PMI): An indicator of the precoding matrix that the terminal prefers in the current channel state.

● Channel Quality Indicator (CQI): The maximum data rate that the terminal can receive in the current channel state. CQI can be replaced by SINR, which can be utilized similarly to the maximum data rate, maximum error correction code rate and modulation method, and data efficiency per frequency.

The RI, PMI, and CQI are related to each other and have meaning. As an example, the precoding matrix supported by LTE/LTE-A is defined differently for each rank. Therefore, the PMI value when RI has a value of 1 and the PMI value when RI has a value of 2 are interpreted differently even if the values are the same. Also, when the UE determines the CQI, it is assumed that the rank value and PMI value notified to the base station are applied by the base station. That is, when the UE notifies the base station of RI_X, PMI_Y, and CQI_Z, when the rank is RI_X and the precoding is PMI_Y, this means that the UE can receive the data rate corresponding to CQI_Z. In this way, when calculating the CQI, the terminal assumes which transmission method the base station will use, allowing it to obtain optimized performance when actual transmission is performed using the corresponding transmission method.

Figure 2b is a diagram illustrating data such as eMBB, URLLC, and mMTC, which are services considered in the NR system, allocated in frequency-time resources along with Forward Compatiable Resource (FCR).

If URLLC data is generated and transmission is required while eMBB and mMTC are allocated and transmitted in a specific frequency band, eMBB and mMTC clear the pre-allocated portion and transmit URLLC data. Among the above services, URLLC is particularly important for short latency, so URLLC data can be allocated and transmitted in a portion of resources allocated to eMBB, and these eMBB resources can be known to the terminal in advance. To this end, eMBB data may not be transmitted in frequency-time resources where eMBB data and URLLC data overlap, and thus the transmission performance of eMBB data may be lowered. That is, in the above case, eMBB data transmission failure may occur due to URLLC allocation. At this time, the length of the transmission time interval (TTI) used for URLLC transmission may be shorter than the TTI length used for eMBB or mMTC transmission.

Figure 2c is a diagram illustrating the assumption that each service is multiplexed in time and frequency resources in the NR system. The base station can allocate CSI-RS to the UE in all bands or multiple bands to secure initial channel state information, such as 2c-10. Such full-band or multiple-band CSI-RS may be disadvantageous in optimizing system performance because it requires a large amount of reference signal overhead. However, in the absence of information obtained in advance, such full-band or multiple-band CSI-RS It may be essential. After this full-band or multiple-band CSI-RS transmission, each service may be provided with different requirements for each service, and the accuracy and update needs of the required channel state information may also vary accordingly. Therefore, after the base station secures this initial channel state information, the base station can trigger subband CSI-RS (2c-20, 2c-30, 2c-40) for each service in the corresponding band according to the need for each service. Although FIG. 2C illustrates transmitting CSI-RS for each service at one time, it is also possible to transmit CSI-RS for multiple services as needed.

As mentioned in FIGS. 2b and 2c above, services in the corresponding band may vary depending on changes in the time and frequency resources of the base station, and taking this into account, various channel and interference situations must be considered. Figure 2d illustrates the service of an interfering cell and the resulting change in interference situation according to the change in time and frequency resources from the eMBB perspective.

In FIG. 2D, one square represents VRG (Vertical Resource Group), which is the basic unit of time and frequency resources set by the base station to the terminal. In FIG. 2D, all VRG resources of cell 1 are set to eMBB. At this time, other cells operate each VRG resource as eMBB, FCR, URLLC candidate resource, etc. Transmission methods may vary depending on the needs of the service in the resource, and the characteristics of interference may vary accordingly. For example, because URLLC requires high reliability, a large number of resources can be used for the service compared to the amount of data transmitted. In addition, since URLLC data has a higher priority than other services, when URLLC needs to be transmitted, the resources of the corresponding terminal are occupied first. Therefore, in the VRG, the change in frequency band may be relatively small compared to the VRG in which eMBB acts as interference, and accordingly, prediction of interference by the base station may be relatively easy. In addition, although not included in FIG. 2d, in the case of mMTC, the interference resource service may be less than URLLC because relatively low-power terminals transmit repeatedly to improve coverage, and for this reason, it is relatively advantageous for data transmission of eMBB terminals. You can. In FIG. 2d, it is assumed that all of Cell 1's resources are set for eMBB transmission, but signal and interference measurements assuming that the resources are set to FCR, URLLC, mMTC, etc. are also necessary, and therefore, this situation can be reflected. A capable channel status measurement and reporting method is needed.

In addition, signal and interference measurements according to time and frequency resources are required for effective CoMP (Coordinated Multipoint) operation and subband BF (Beamformed) CSI-RS operation. Figure 2e illustrates a base station transmitting CSI-RS to effectively measure and report channel state information in NR.

The optimal beam direction may vary for each frequency band, and accordingly, it may be effective to transmit different analog and digital beams for each frequency band. In the case of analog beams, different signals cannot be transmitted for each frequency band due to hardware limitations, but in the case of digital beams, it is sufficient to vary the phase of the corresponding signal, so as shown in Figures 2e-10 and 2e-20, different beams for each frequency band can be transmitted, and CSI-RS can be transmitted based on this. Additionally, it is possible to transmit not only from different beam directions but also from TRPs (Transmission Reception Points) located geographically. In the case of the existing LTE CSI-RS, it was designed assuming that the same signal is transmitted across all bands, and a different design from the existing one is needed to enable different services, beams, and CoMP scenarios to be assumed for different time and frequency resources as described above. .

eMBB/URLLC/mMTC resources for each service and resources to support channel state measurement and reporting of other beam and CoMP scenarios may be a single PRB (Physical Resource Block) or multiple PRB units. The plurality of PRB units include Service Group (SG), Service Resource Group (SRG), Vertical Group (VG), Vertical resource Group (VRG), Frequency Resource block Group (FRG), Physical Resource block Group (PRG), and MPG ( Multiple PRB group), etc. In addition, since the above settings can simultaneously consider not only frequency but also time and frequency resources, in this case, the corresponding resources may also be called a Time and Frequency Resource block Group (TFRG). Although the following description of this specification is based on VRG, VRG in the following description can be replaced with all the terms mentioned above and similar terms.

The VRG resource setting unit mentioned above must be specified according to time and frequency resources. At this time, the unit of time resource can be defined as one value in the standard or set through RRC. When defined as one value in the standard, the service conversion unit of multiple cells can be set to one value, so the service conversion unit for interference with the signal from the base station transmitting data also matches, and thus the corresponding interference changes. can be predicted relatively easily. However, when the base station does not frequently need service conversion in time resources, it may increase unnecessary configuration overhead if it is defined as one small time unit (e.g., one slot or subframe). Also, in the opposite case, if the time unit is large (e.g., tens of ms, etc.), the service cannot be switched flexibly in time resources according to the needs of the base station, resulting in a decrease in system performance and service requirements. may not be satisfied. Therefore, the corresponding time resource unit must be determined taking this into account.

If set through RRC, multiple base stations or TRPs can each freely convert the time service unit, and thus the time unit can be freely set and used according to the needs of the system. However, in order to satisfy this, the terminal implementation becomes complicated, and from the terminal's perspective, other cells also use time units that change depending on the service needs, so predicting interference may become relatively difficult. Therefore, it is desirable to limit the configurable time units to only specific values. Table 2i below illustrates the service unit designation field at the time for this VRG setting.

[Table 2i] Time resource granularity configuration for VRG

In the above example, the base station can set the size of the time resource to the terminal as one of 5ms, 10ms, 20ms, and 40ms, and the terminal can determine the size and number of VRG time resources based on this and operate accordingly. In the above example, the number of time units that the base station can set for the terminal can be changed. In the above example, the number is set in ms, but the unit may be various units such as TTI or subframe. In addition, although the above example illustrates setting a direct number, it is also possible to indirectly set it to type A, type B, etc. rather than a direct number, and in this case, the type setting may include such a time unit.

As mentioned above, setting the size at the frequency of VRG can also be defined as a single value in the standard or set through RRC. When defined as one value in the standard, the service conversion unit at the frequency of multiple cells can be set to one value, so the service conversion unit for interference with the signal from the base station transmitting data also matches, and therefore the interference Changes can be predicted relatively easily. However, when the base station does not frequently need service conversion in frequency resources, if it is defined as one small frequency unit (e.g., one PRB), unnecessary configuration overhead may increase. Also, in the opposite case, if the frequency resource unit is large (e.g., tens of PRBs, etc.), the service cannot be flexibly switched in time resources according to the needs of the base station, resulting in deterioration of system performance and service interruption. Requirements may not be met. Therefore, the corresponding frequency resource unit must be determined taking this into account. When determining the frequency resource unit according to the standard as above, the effective frequency resource unit may vary depending on the size of the system band. In other words, if the system band is relatively small, it is important to divide it into small pieces and multiplex the band efficiently, but if the system band is sufficient, it may be preferable to divide it into large chunks and use it efficiently rather than dividing it into small chunks and increasing setup overhead. . Table 2j below is a table illustrating the VRG size in the frequency band changing depending on the size of the system band by illustrating the corresponding frequency resource as VRG.

[Table 2j] VRG Size in frequency with system bandwidth

In Table 2j above, the size of the VRG changes depending on the set system band, and based on the VRG with the service unit of this frequency band, the base station can set the terminal to support different services or vertical for each VRG. At this time, Table 2j is a table illustrating that the VRG Size varies depending on the system band setting, and the direct numbers of the system band range and VRG Size in the table may vary.

Additionally, VRG service units can be set in frequency units through RRC. In this case, multiple base stations or TRPs can each freely convert the corresponding frequency service unit, and thus the frequency unit can be freely set and used according to the needs of the system. However, in order to satisfy this, terminal implementation becomes complicated, and from the terminal's perspective, other cells also use frequency units that change depending on the service needs, so predicting interference may become relatively difficult. Therefore, it is desirable to limit the settable frequency units to only specific values. Table 2k below illustrates the service unit designation fields in the frequency for this VRG setting.

[Table 2k] frequency resource granularity configuration for VRG

In the above example, the base station can set the size of the time resource to the terminal as one of 5 PRB, 10 PRB, 20 PRB, and 40 PRB, and the terminal can determine the size and number of VRG time resources based on this and operate accordingly. You can. In the above example, the number of time units that the base station can set for the terminal can be changed. In the above example, the number is set in PRB units, but the unit may be various units such as RBG or subband. In addition, although the above example illustrates setting a direct number, it is also possible to indirectly set it to type A, type B, etc. rather than a direct number. In this case, the type setting may include such a frequency unit. In addition, when setting indirectly, such as type A or type B, the indirect setting may include not only the frequency unit but also the time unit.

Based on the time and frequency resource sizes of the VRGs mentioned above, the number of VRGs supported by the system can be calculated, which can be expressed as Equation 2b below.

[Equation 2b]

In the above equation, the number of VRGs is expressed as dividing the number of subframes in one frame by the subframes in VRG time units, but the corresponding unit, subframe, can be expressed in various units such as ms or TTI. The number of VRGs in the frequency is also expressed by dividing the system band expressed in PRB numbers by the PRB number, which is the VRG unit in the frequency, but the PRB can be expressed in various numbers such as RBG or subband. Additionally, in the above example, if the number of VRGs in the time band is one, the number of VRG resources can be expressed only by the number of VRGs in the frequency resource.

Based on Equation 2b above, the base station can directly or indirectly set the service or vertical settings of the corresponding VRG to the terminal based on the calculated number of VRGs. The settings can be provided individually by setting fields for all VRG resources, or by dividing the fields by time and frequency. Table 2l below is an example of providing setting fields individually to all VRG resources.

[Table 2l] VRG type configuration field

To set the service type of the VRG resource, the size of the corresponding bitmap can be calculated by multiplying the number of VRGs that can be calculated in Equation 2b by the number of bits that can be set for each VRG. This method has the advantage that the VRG type can be set for each VRG setting, allowing settings for all possible combinations, but it has the disadvantage that a large-sized bitmap is required for the setting, and the setting overhead increases accordingly. Additionally, these shortcomings are further maximized when set for each band or band combination considering CA (Carrier Aggregation) or other bands. The above method is exemplified assuming that the bitmap is set for all VRGs in the system at once, but these setting fields can be provided separately for each VRG.

In order to reduce this configuration overhead, the service type settings of the VRG resources can be set separately for each available VRG resource. In other words, it can be set separately for each VRG in time units and VRG in frequency units. Table 2m below is an example of providing setting fields for each time and frequency.

[Table 2m] VRG type configuration field

In Table 2m, each field represents a setting field for VRG resources for each time and frequency. Through this, the overhead for VRG settings can be reduced. For example, if there are 10 VRG resources for each time and frequency, there must be a configuration field for all VRG resources, and if the configuration field is assumed to be 2 bits, an overhead of 200 bits is required. However, if they are set separately by time and resource, and 1 bit is set for the time resource and 2 bits are set for the frequency resource, 10 bits and 20 bits are required respectively, and therefore the setting may be possible with a total of 30 bits. When divided into time and frequency resources as above, the time or frequency resource can indicate whether the setting of one resource allows the setting of another resource. Table 2n below illustrates this 1-bit setting.

[Table 2n] 1 bit VRG type configuration

For example, if 1 bit can be set for the time resource using the field in Table 2n, it indicates whether the time resource is a resource that can be set to various services. At this time, if the resource is not configurable, the resource may belong to a specific service, for example, eMBB, and if this service is not configurable in the standard, it is assumed to be eMBB or a value corresponding to eMBB. It can be expressed as In addition, it is possible to inform the terminal of the basic service for these non-configurable values by selecting one of ‘eMBB’, ‘mMTC’, and ‘eMBMS’ through the RRC field. In the above example, the time resource is set to 1 bit using the table above and an individual service is set to the frequency resource. However, on the contrary, it is also possible to set the frequency resource to 1 bit and set an individual service to the time resource. In addition, although it is written as 'not configurable' in the above example, it is also possible to write the description of the field as 'eMBB', 'mMTC', 'eMBMS', etc. and, if configurable, follow the value of the detailed settings. .

Table 2o and Table 2p below illustrate fields that directly set VRG service settings or vertical according to VRG setting fields of 2 or 3 bit size.

[Table 2o] 2 bit VRG type configuration

[Table 2p] 3 bit VRG type configuration

The service type can be directly set for each VRG using a predetermined table, such as Table 2o and Table 2p. This setting method can be used for all of the above-mentioned VRG-specific setting fields or VRG setting fields that are set separately according to time/frequency resources. As can be seen from Tables 2o and 2p above, if many bits are used when directly setting the VRG type as above, the corresponding service type can be announced in more detail, and the 'reserved' field can be used to provide services that may be needed in the future. You can also prepare for that field. However, since this increase in the amount of instructions increases the corresponding configuration overhead, the decision must be made by judging the utility of the service configuration compared to the increase in overhead. In addition, in the case of the direct setting method as described above, the type of the service is set in advance to the terminal, so not only does the channel state information be measured for each resource, but the terminal also predicts and anticipates the operation of the service. There is an advantage that the operation of the terminal can be optimized according to this. Additionally, as indicated for eMBMS in Table 2p above, multiple types may be supported for one service. For example, in the case of eMBMS, the terminal can be configured for two or more MBSFN areas. In this case, even if two VRGs operate for the same eMBMS service, the settings such as MCS in the area may be different, and these multiple You can support other settings through settings.

In the case of channel state information, URLLC has different requirements for operation compared to eMBB. In other words, eMBB operates with a BLER of 10%, but URLLC may require high reliability, such as 1-10^-5, due to its characteristics, and thus may operate with an error probability of 10^-5. However, the current LTE CQI is required to report an MCS that can operate at a BLER of 10%, so it is not suitable for link adaptation for URLLC operation. Therefore, if the VRG is set up for a URLLC service, it can report information such as CQI or MCS and coding rate appropriate for the service.

In addition to the CQI with other reliability for URLLC, CSI for URLLC can support a CQI table that supports lower modulation and coding rate. Tables 2q, 2r, and 2s below are the CQI table for 64QAM-based data transmission, the CQI table for 256QAM-based data transmission, and the CQI table for NB-IOT support in LTE, respectively.

[Table 2q] CQI table for medium transmission rate

[Table 2r] CQI table for high transmission rate

[Table 2s] CQI table for low transmission rate and/or high reliability

The table above can be used as an example of high data rate, medium data rate, and low data rate or data rate for high reliability, respectively. Therefore, in the case of channel state information set to eMBB or used for eMBB, all of the plurality of CQI tables may be set. However, in the case of channel state information used for URLLC, considering the high reliability required by URLLC, there may be no need to consider high modulation or coding rate. Accordingly, channel state information for URLLC may be set only in a CQI table that maximally supports a medium (64QAM) or low (16QAM) data rate among the plurality of CQI tables. Setting of this CQI table can be supported using the following method.

High reliability CQI table setting method 1: Direct setting through independent RRC field setting

Method 2 of setting a high reliability CQI table: Indirectly setting through RRC field setting together with a high reliability CQI

Method 3 to set up a highly reliable CQI table: Directly set through independent DCI field settings

Method 4 for setting a high-reliability CQI table: Indirectly setting the DCI field set together with a high-reliability CQI

Method 1 of setting the CQI table is a method of setting it directly through independent RRC field setting. In this case, it may be possible to set based on a setting field independent of the CQI considering the high reliability mentioned above. This method has the advantage that the base station can freely set the CQI table necessary for URLLC transmission depending on the implementation. Additionally, this method allows channel status reporting based on a CQI table that varies depending on the terminal for URLLC transmission.

Method 2 of setting the CQI table is a method of setting it indirectly through setting the RRC field together with a high reliability CQI. In the case of URLLC, high reliability CQI is required simultaneously with low modulation and coding rate. Therefore, if the channel status information is set separately, the overhead for setting may increase. Therefore, by enabling the above methods to be set simultaneously, the terminal can support channel state information reporting for URLLC. In this case, unlike CQI table setting method 1, the corresponding CQI table can support only one CQI table defined in the standard in advance among a plurality of tables.

Method 3 of setting the CQI table is a method of setting it directly through independent DCI field setting. In this case, it may be possible to set based on a setting field independent of the CQI considering the high reliability mentioned above. This method has the advantage that the base station can freely set the CQI table necessary for URLLC transmission depending on the implementation. In addition, channel status information can be reported by dynamically changing eMBB and URLLC for transmission or by dynamically changing the target data rate of eMBB as needed.

Method 4 of setting the CQI table is a method of setting it indirectly through setting the RRC field together with a high reliability CQI. In the case of URLLC, high reliability CQI is required simultaneously with low modulation and coding rate. Therefore, if the channel status information is set separately, the overhead for setting may increase. Therefore, by enabling the above methods to be set simultaneously, the terminal can support channel state information reporting for URLLC. In this case, channel status information can be reported by dynamically changing eMBB and URLLC or by dynamically changing the target data rate of eMBB as needed. In this case, unlike CQI table setting method 1, the corresponding CQI table can support only one CQI table defined in the standard in advance among a plurality of tables.

In the above example, three CQI tables are illustrated, but there may be more CQI tables. In addition, in the above example, the CQI table supporting high data rate supports up to 256QAM, but in addition, 1024 QAM can be supported. In addition, in the above example, the CQI table to provide high reliability supports a maximum of 16 QAM, but a lower modulation, for example, only QPSK, may be supported.

In addition, in the case of channel state information reporting for URLLC, the rank allowed for reporting may be limited. As with the modulation and coding rates above, data transmission based on high rank is difficult to guarantee high reliability. Therefore, the amount of information required for channel state information reporting can be reduced by limiting the rank used for channel state information reporting for URLLC. This setting method is possible through the following method.

RI limit setting method for URLLC 1: Direct setting through independent RRC field setting

RI limit setting method for URLLC 2: Indirect setting through RRC field setting with high reliability CQI

Method 3 for setting RI restrictions for URLLC: Codebook subset restriction set directly through RRC field settings

RI limit setting method for URLLC 4: Direct setting through independent DCI field setting

RI limit setting method for URLLC 5: Indirect setting through DCI field setting with high reliability CQI

RI limit setting method 1 for URLLC is a method of setting directly through independent RRC field setting. In this case, it may be possible to set the CQI and CQI table considering the high reliability mentioned above and based on a setting field independent of . This method has the advantage that the base station can freely set the RI limit necessary for URLLC transmission depending on the implementation.

RI limit setting method 2 for URLLC is a method of setting indirectly through RRC field setting along with a high reliability CQI and CQI table. In the case of URLLC, high reliability CQI and RI limits may be simultaneously required along with low modulation and coding rates. Therefore, if the channel status information is set separately, the overhead for setting may increase. Therefore, by enabling the above methods to be set simultaneously, the terminal can support channel state information reporting for URLLC. In this case, the corresponding RI limit may support only one of the RIs defined in the standard in advance, for example, 2 or 3.

RI limit setting method 3 for URLLC is a method of setting indirectly through setting the codebook sublimit RRC field. PMI and RI limit settings can be supported using the same method as the eMBB service.

RI limit setting method 4 for URLLC is a method of setting directly through independent DCI field setting. In this case, it may be possible to set based on a setting field independent of the CQI considering the high reliability mentioned above. This method has the advantage that the base station can freely set the CQI table necessary for URLLC transmission depending on the implementation. In addition, channel status information can be reported by dynamically changing eMBB and URLLC for transmission or by dynamically changing the target data rate of eMBB as needed.

RI limit setting method 5 for URLLC is a method of setting indirectly through RRC field setting together with a high reliability CQI and CQI table. In the case of URLLC, high reliability CQI and RI limits may be simultaneously required along with low modulation and coding rates. Therefore, if the channel status information is set separately, the overhead for setting may increase. Therefore, by enabling the above methods to be set simultaneously, the terminal can support channel state information reporting for URLLC. In this case, channel status information can be reported by dynamically changing eMBB and URLLC or by dynamically changing the target data rate of eMBB as needed. In this case, the corresponding RI limit may support only one of the RIs defined in the standard in advance, for example, 2 or 3.

Additionally, a separate Transport block size (TBS) table may be supported to support URLLC transmission. The terminal can receive modulation and coding rate for data transmission through MCS along with data scheduling resource information, and this MCS information can be used by the terminal to obtain TBS size information necessary for decoding downlink transmission. The settings of these TBS tables can be set independently through DCI or RRC settings, or together with the CQI, CQI table, or RI limit settings for URLLC transmission with high reliability mentioned above.

In addition, the transmission technique for transmitting the URLLC data may be limited. As explained above, since the data transmission requires high transmission reliability, diversity-based transmission techniques are used rather than spatial multiplexing-based transmission techniques, for example, transmit diversity or large delay CDD, or semi-open-loop or beam. A diversity-based transmission technique may be advantageous. Like the TBS setting above, the setting of this transmission technique can be set independently through DCI or RRC setting, together with the CQI, CQI table, RI limit setting or TBS table setting for URLLC transmission with high reliability mentioned above. can be set.

Additionally, the methods mentioned above can be used for other services as well. For example, in the case of mMTC, a CQI with high reliability is not required, but setting a low transmission rate CQI table and TBS table, setting RI limits, and limiting transmission techniques may be necessary. Therefore, in order to support the technique for these terminals, the methods are not a URLLC-specific CQI table or an mMTC CQI table, but rather a CQI with high transmission rate, medium transmission rate, low transmission rate, high reliability, medium reliability, and low reliability, CQI table, It may be called a TBS table, etc. In addition, it can also be expressed as alternative CQI, alternative CQI table, alternative TBS table, etc., and can also be expressed as CQI and CQI tables I, II, III, etc.

As another example, when set to eMBMS, channel state information may not be reported. eMBMS is a specialized service for broadcasting and does not use link adaptation, and all terminals in the area must be able to receive the data. Therefore, an MCS suitable for the terminal is used so that even the terminal with the lowest signal-to-interference ratio (SINR) can receive the signal. Considering this, reporting channel state information may not be necessary for the corresponding band. If channel status information is not reported according to the service settings, information such as RI, PMI, CQI, etc. may be excluded from transmission of the information or may be fixed to a specific bit such as 0. By using the above method to minimize the amount of channel state information transmitted in the uplink, coverage and transmission performance of the information can be improved, and system performance can be streamlined.

The direct service setting method as described above has the advantage of being able to transmit control signals, data, and channel status information in a method optimized for the service, and thus the system can be used efficiently. However, for NR, there may be a need to reserve many fields assuming that new services will be introduced in the future, and a sufficient number of reserve fields must be secured to prevent this. However, this case has the disadvantage that the field setting overhead may increase excessively. Tables 2o and 2p above are examples of direct service type settings for VRG, and the values and services of the corresponding direct fields may vary. Additionally, the table above exemplifies fields using 2 bits and 3 bits, but the number of bits in the actual field may differ from the table above.

Table 2t below is a table showing indirect VRG set settings through a 2-bit VRG setting field.

[Table 2t] 2 bit VRG type configuration

Unlike the direct VRG service type setting mentioned above, the method in Table 2t is a method of specifying and using an indirect service set. A base station does not need to support all service types and can only use a few sets of services as needed. When using the methods of Tables 2o and 2p above, all base stations must use configuration bits according to all service types, which increases configuration overhead. Therefore, if information is provided in the form of an indirect service set as described above, such setup overhead can be minimized, and the base station can enjoy the effect of the VRG by grouping and managing the VRG. However, additional settings are required to perform specialized operations for each service mentioned above. For example, if you have the fields mentioned in Table 2o or Table 2p for each service set, you can directly set the service type for each service set without having to support all fields for each VRG, and use this to minimize setup overhead. there is.

In addition, channel status information specialized for services such as URLLC can be used by using not only the above format but also additional fields for the corresponding service. Table 2u illustrates these additional fields.

[Table 2u] VRG type configuration field

As described above, a separate field for URLLC or FCR settings can be set within the VRG settings field, and the terminal can support the corresponding feedback or related operations through the settings of the field. At this time, the AdvancedCSI field uses more overhead but can be set for eMBB operation as a field to provide improved channel state information that provides accurate information.

Additionally, the direct VRG service type setting and indirect type setting mentioned above can be used in combination. For example, eMBB is a common service in all base stations and is used frequently. Therefore, field 00 can be set directly with eMBB, and the remaining three fields can be used as a service set. Table 2t above is an example of indirect service type settings for VRG, and the expression of the corresponding indirect field may vary. Additionally, the table above exemplifies a field using 2 bits, but the actual number of bits in the field may differ from the table above.

In order to manage the VRG setting information mentioned above, the base station can add an ID to the VRG setting information in the corresponding field. Table 2v illustrates these ID fields.

[Table 2v] VRG Info ID

Through the VRG setting ID, the base station can easily set or trigger the VRG-related information when using periodic CSI-RS and channel state information reporting or aperiodic CSI-RS and channel state information reporting through aperiodic triggering. . The ID may be one of the number of VRG information that can be set from 0 to the maximum.

As mentioned above, service/vertical allocation in these frequency-time resources can be supported to be set on a VRG basis, and this setting can be semi-static setting through RRC or transmitting control information to a specific group of terminals simultaneously. It can be dynamically set through downlink control information (eg group DCI/common DCI, etc.). When a semi-static setting is supported through RRC, there is little change in the interference situation because the service/vertical allocation in time and frequency resources is constant for a long period, and therefore, neighboring base stations are more likely to reduce the interference situation of the cell. You can understand it well. However, in the case of this method, the performance for service/vertical support may deteriorate because the adaptation cycle according to changes in traffic characteristics of the TRP is long. For example, in the case of a base station that does not require mMTC or URLLC transmission, pre-allocating these resources may cause a decrease in system performance. Therefore, such system performance degradation can be prevented by setting all resources as eMBB resources. However, if the base station suddenly needs to transmit URLLC, etc., the service cannot be supported before the RRC is reset, so if this possibility exists, the base station must set a certain amount of resources in advance as the service resources. Accordingly, the performance of the base station may deteriorate. If it can be set dynamically through downlink control information, the amount of time and frequency resources secured in advance may be small because such traffic generation can be responded to in a relatively quick time. Therefore, relatively high system performance can be achieved, but there is a disadvantage in that control signal overhead occurs through DCI, etc. This group DCI is transmitted at a prearranged time between the base station and the terminal, and may be scrambled and transmitted based on the set group RNTI.

In order to trigger aperiodic CSI-RS transmission and channel state information reporting for the VRG, the base station can transmit information about the corresponding VRG set to the terminal. Table 2w and Table 2x illustrate fields for triggering aperiodic CSI-RS transmission and channel state information reporting for the VRG set.

[Table 2w] Aperiodic CSI-RS and CSI reporting trigger via VRG

[Table 2x] Aperiodic CSI-RS and CSI reporting trigger via VRG

Table 2w shows a method for triggering by Wideband CSI-RS or VRG ID based on preset VRG setting information and corresponding ID. This method has the advantage of being able to transmit CSI-RS only to the VRG for each service that must be transmitted as needed, but has the disadvantage of requiring multiple downlink control information to be transmitted in order to trigger on multiple VRGs.

Table 2x shows a method for triggering CSI-RS and related channel state information based on a preset VRG configuration information set. Table 2y below illustrates these trigger field settings.

[Table 2y] VRG set configuration for CSI-RS and CSI reporting

In Table 2y, each trigger field represents VRG information for which CSI-RS and channel status reporting will be made through the corresponding trigger. For example, if the first and second bits of trigger010 are set to 1 and the remaining bits are 0, CSI-RS and channel status reporting can be made in VRGs corresponding to VRG IDs 0 and 1. At this time, in the above example, it is assumed that the number of settings and the number of trigger bits in Table 2x are the same, but these fields may be different, and this is downlink control information (group) that can simultaneously transmit control information to a specific group of terminals. It can be set dynamically through DCI/common DCI, etc.). Table 2z below is a field illustrating this.

[Table 2z] Aperiodic CSI-RS and CSI reporting trigger via VRG

As shown in Table 2z above, the base station can transmit 2 bits through downlink control information transmitted to the terminal, and the 2 bits represent the lowest index and the highest index among the allowed VRG set. At this time, the base station can inform the terminal of possible VRG sets through group DCI, and the size of the corresponding bitmap may be equal to the number of VRG set settings. For example, if the base station transmits 01001000 and 00110000 for the first and second sets, respectively, through group DCI, the terminal triggers this for the VRG with ID 1 and ID 4 in the first set and 2 in the second set. It is recognized as being set to enable VRG of ID and 3. Therefore, based on this, when trigger '10' comes, CSI-RS for VRGs with IDs 1 and 4 is received, and when trigger '11' comes, CSI-RS is received for VRGs with IDs 2 and 3, and channel status information is measured. and report.

As mentioned above, configuration fields such as Table 2aa below can be used for CSI-RS transmission, IMR resource configuration, and channel status reporting configuration.

[Table 2aa] CSI-RS/CSI-IM/CSI reporting configs in VRG Info

As shown in Table 2aa above, the field may include CSI-RS settings and CSI-IM settings, and the settings may include the number of ports for NP CSI-RS and antennas for each dimension if the setting supports aperiodic CSI-RS. It may include N1 and N2, which are the numbers, O1 and O2, which are oversampling factors for each dimension, one subframe config for transmitting multiple CSI-RSs, and multiple resource configs for setting locations. Periodic CSI-RS If supported, subframe config information may be additionally included in the information. The port number information of CSI-IM can be fixed to the standard, and like CSI-RS, if the resource is aperiodic, it can only include resource config. If it is set periodically, subframe config information can be included in addition to the information. .

In the above, it was explained that CSI-RS and channel state information are configured for each VRG, but in order to support the VRG mentioned differently, the corresponding settings may be supported as a measurement subset. In the case of the above-mentioned CSI-RS and channel state information reporting allocation for each VRG, the terminal has been set, but CSI-RS and channel state information reporting may be allocated including areas where the base station does not transmit data, and this allocation is It can be a waste. Therefore, for efficient resource use, CSI-RS settings and channel state information reporting settings can be separated from VRG settings. In this case, VRG settings can indirectly act as a measurement subset in the channel state reporting measurements. Table 2ab below illustrates VRG settings for measurement subset operation.

[Table 2ab] VRG type configuration field

As mentioned in Table 2ab above, individual codebook subset restrictions and PC settings are required for measurement subset operation. Therefore, when performing measurement subset operation for each VRG, codebook subset restriction and PC can be set in individual VRG fields as shown in the example above. The terminal can individually report CRI, PTI, RI, PMI, CQI, etc. based on the measurement set, and as mentioned above, channel status information such as CRI, RI, PTI, PMI, CQI, etc. is provided by the service. It may vary depending on the type setting or the corresponding feedback type setting. This method has the advantage of not requiring additional overhead other than VRG settings for subset restriction, but has the disadvantage of not being able to additionally reflect changes in the interference situation due to changes in services of other cells within the VRG.

A measurement subset can be supported within the VRG to measure interference changes by other services, beam directions, and CoMP scenarios within the VRG mentioned above. For this support, CSI-RS and channel state information triggers for each VRG mentioned in Tables 2w to 2z above may be desirable. This VRG subframe subset method may support independent fields for each VRG subset or may support separate fields. Table 2ac below is an example of supporting independent fields for each measurement subset for up to three measurement subsets in the VRG.

[Table 2ac] VRG Size with system bandwidth

Unlike the existing subframe subset, there may be more than two subset settings because there are two or more interference situations in the frequency band. Additionally, a list of relevant settings may be indicated for individual PC and codebook subset restriction settings, and in this case, the list of relevant settings is equal to the number of VRG measurement subsets set. In the above example, a setting field is provided for each measurement set, but unlike the above example, it is also possible to support two measurement sets with one field. However, in this case, because only two measurement sets can be supported, there may be limitations in measurable interference situations. To prevent this, an additional setting field can be added to support four measurement sets.

Since it may be difficult for all terminals to support the plurality of VRG settings, the terminal may inform the base station of the UE capability for the corresponding settings. Table 2ad below illustrates the fields for reporting this UE capability.

[Table 2ad] UE capability on VRG

As described above, the terminal can inform the base station about the number of VRGs that the terminal can support and the measurement subframe set that can be supported for each VRG. This makes it easier to implement the terminal and support the service more flexibly. If this capability indication is not supported, NR terminal implementation may become complicated and the unit price of the terminal may increase due to difficulties in implementation.

Figure 2f is a flowchart showing the operation sequence of a terminal according to an embodiment of the present invention.

Referring to Figure 2f, the terminal receives setting information for VRG configuration in step 1910. At least one of VRG-related ID, time of each VRG, frequency resource location, service type, service set, supported feedback type, and VRG measurement subset may be set in this information. In addition, based on the received configuration information, the terminal determines the number of ports for each NP CSI-RS, the number of antennas for each dimension, N1 and N2, and the oversampling factors for each dimension, O1 and O2, for transmitting multiple CSI-RSs. You can check at least one of multiple resource configs for setting one subframe config and location, codebook subset restriction-related information, CSI reporting-related information, CSI-process index, and transmission power information (PC). Afterwards, the terminal configures one feedback configuration information based on the CSI-RS location in step 1920. The information may include PMI/CQI period and offset, RI period and offset, CRI period and offset, wideband/subband status, submode, etc. When the terminal receives CSI-RS based on the corresponding information in step 1940, it estimates the channel between the base station antenna and the terminal's reception antenna based on this. In step 1940, the terminal generates feedback information rank, PMI, and CQI using the received feedback settings based on the estimated channel, and selects the optimal CRI based on this. Thereafter, in step 1950, the terminal transmits the feedback information to the base station at a feedback timing determined according to the base station's feedback settings or an aperiodic channel state reporting trigger, thereby completing the channel feedback generation and reporting process.

Figure 2g is a flowchart showing the operation sequence of the base station according to an embodiment of the present invention.

Referring to Figure 2g, the base station transmits setting information for VRG for channel measurement to the terminal in step 2010. The configuration information may be set to at least one of the time, frequency resource location, service type, supported feedback type, and VRG measurement subset of each VRG, and based on this, the number of ports for NP CSI-RS to transmit CSI-RS. , N1 and N2, the number of antennas for each dimension, O1 and O2, the oversampling factors for each dimension, one subframe config for transmitting multiple CSI-RSs and multiple resource configs for setting the location, codebook subset restriction related information, CSI It may include at least one of reporting-related information, CSI-process index, and transmission power information (PC). Afterwards, the base station transmits feedback configuration information based on at least one CSI-RS to the terminal in step 2020. The information may include PMI/CQI period and offset, RI period and offset, CRI period and offset, wideband/subband status, submode, etc. Afterwards, the base station transmits the configured CSI-RS to the terminal. The terminal estimates a channel for each antenna port and estimates additional channels for virtual resources based on this. The terminal determines the feedback, generates the corresponding CRI, PMI, RI, and CQI and transmits it to the base station. Accordingly, the base station receives feedback information from the terminal at a determined timing in step 2030 and uses it to determine the channel status between the terminal and the base station.

Figure 2h is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention.

Referring to Figure 2h, the terminal includes a communication unit 2110 and a control unit 2120. The communication unit 2110 performs a function of transmitting or receiving data from the outside (eg, a base station). Here, the communication unit 2110 can transmit feedback information to the base station under the control of the control unit 2120. The control unit 2120 controls the status and operation of all components constituting the terminal. Specifically, the control unit 2120 generates feedback information according to information allocated from the base station. Additionally, the control unit 2120 controls the communication unit 2110 to feed back the generated channel information to the base station according to timing information allocated from the base station. For this purpose, the control unit 2120 may include a channel estimation unit 2130. The channel estimation unit 2130 determines the location of the VRG in time and frequency resources through the VRG service and feedback information received from the base station, and confirms the necessary feedback information through the related CSI-RS and feedback allocation information. . A channel is estimated using the received CSI-RS based on the feedback information. In FIG. 2H, an example in which the terminal consists of a communication unit 2110 and a control unit 2120 is described, but the terminal is not limited to this and may further have various configurations depending on the functions performed in the terminal. For example, the terminal may further include a display unit that displays the current state of the terminal, an input unit that receives signals such as performing functions from the user, and a storage unit that stores data generated in the terminal. In addition, although the channel estimation unit 2130 is shown above as being included in the control unit 2120, it is not necessarily limited thereto. The control unit 2120 may control the communication unit 2110 to receive configuration information for each of at least one reference signal resource from the base station. Additionally, the control unit 2120 may control the communication unit 2110 to measure the at least one reference signal and receive feedback setting information for generating feedback information according to the measurement result from the base station.

Additionally, the control unit 2120 may measure at least one reference signal received through the communication unit 2110 and generate feedback information according to the feedback setting information. And the control unit 2120 may control the communication unit 2110 to transmit the generated feedback information to the base station at a feedback timing according to the feedback setting information. Additionally, the control unit 2120 may receive a Channel Status Indication - Reference Signal (CSI-RS) from the base station, generate feedback information based on the received CSI-RS, and transmit the generated feedback information to the base station. . At this time, the control unit 2120 may select a precoding matrix for each antenna port group of the base station and select one additional precoding matrix based on the relationship between the antenna port groups of the base station. there is.

Additionally, the control unit 2120 may receive CSI-RS from the base station, generate feedback information based on the received CSI-RS, and transmit the generated feedback information to the base station. At this time, the control unit 2120 can select one precoding matrix for all antenna port groups of the base station. Additionally, the control unit 2120 receives feedback configuration information from the base station, receives CSI-RS from the base station, generates feedback information based on the received feedback configuration information and the received CSI-RS, and generates feedback information based on the received CSI-RS. Feedback information can be transmitted to the base station. At this time, the control unit 2120 may receive feedback configuration information corresponding to each antenna port group of the base station and additional feedback configuration information based on the relationship between antenna port groups.

Figure 2i is a block diagram showing the internal structure of a base station according to an embodiment of the present invention.

Referring to Figure 2i, the base station includes a control unit 2210 and a communication unit 2220. The control unit 2210 controls the status and operation of all components constituting the base station. Specifically, the control unit 2210 allocates CSI-RS resources for related settings and channel estimation for the terminal to acquire VRG information to the terminal, and allocates feedback resources and feedback timing to the terminal. To this end, the control unit 2210 may further include a resource allocation unit 2230. In addition, feedback settings and feedback timing are assigned to prevent feedback from multiple terminals from colliding, and feedback information set at the corresponding timing is received and interpreted. The communication unit 2220 performs the function of transmitting and receiving data, reference signals, and feedback information to the terminal. Here, the communication unit 2220 transmits CSI-RS to the terminal through resources allocated under the control of the control unit 2210 and receives feedback on channel information from the terminal. In addition, a reference signal is transmitted based on CRI, rank, partial PMI information, CQI, etc. obtained from channel state information transmitted by the terminal.

In the above, the resource allocation unit 2230 is shown as being included in the control unit 2210, but it is not necessarily limited thereto. The control unit 2210 may control the communication unit 2220 to transmit setting information for each of at least one or more reference signals to the terminal, or may generate the at least one or more reference signals. Additionally, the control unit 2210 may control the communication unit 2220 to transmit feedback setting information for generating feedback information according to the measurement result to the terminal. Additionally, the control unit 2210 may control the communication unit 2220 to transmit the at least one reference signal to the terminal and receive feedback information transmitted from the terminal at a feedback timing according to the feedback setting information. Additionally, the control unit 2210 may transmit feedback configuration information to the terminal, transmit a CSI-RS to the terminal, and receive feedback information generated based on the feedback configuration information and the CSI-RS from the terminal. . At this time, the control unit 2210 may transmit feedback configuration information corresponding to each antenna port group of the base station and additional feedback configuration information based on the relationship between antenna port groups. Additionally, the control unit 2210 may transmit a beamformed CSI-RS to the terminal based on feedback information and receive feedback information generated based on the CSI-RS from the terminal. According to the above-described embodiment of the present invention, it is possible to prevent allocating excessive feedback resources for transmitting CSI-RS in a base station with a large number of transmission antennas in a two-dimensional antenna array structure and increasing the channel estimation complexity of the terminal. In addition, the terminal can effectively measure all channels for a large number of transmission antennas, configure this as feedback information, and notify the base station.

<Third Embodiment>

In order to meet the increasing demand for wireless data traffic following the commercialization of the 4G communication system, efforts are being made to develop an improved 5G communication system or pre-5G communication system. For this reason, the 5G communication system or pre-5G communication system is called a Beyond 4G Network communication system or a Post LTE system. To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (such as the 60 GHz band). In order to alleviate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, the 5G communication system uses beamforming, massive array multiple input/output (massive MIMO), and full dimension multiple input/output (FD-MIMO). ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, to improve the network of the system, the 5G communication system uses advanced small cells, advanced small cells, cloud radio access networks (cloud RAN), and ultra-dense networks. , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation. Technology development is underway. In addition, the 5G system uses FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), which are advanced coding modulation (ACM) methods, and advanced access technologies such as FBMC (Filter Bank Multi Carrier) and NOMA. (non-orthogonal multiple access), and SCMA (sparse code multiple access) are being developed.

Meanwhile, the Internet is evolving from a human-centered network where humans create and consume information to an IoT (Internet of Things) network that exchanges and processes information between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection to cloud servers, etc., is also emerging. In order to implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, sensor networks for connection between things, and machine to machine communication (Machine to Machine) are required to implement IoT. , M2M), and MTC (Machine Type Communication) technologies are being researched. In the IoT environment, intelligent IT (Internet Technology) services that create new value in human life can be provided by collecting and analyzing data generated from connected objects. IoT is used in fields such as smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliances, and advanced medical services through the convergence and combination of existing IT (information technology) technology and various industries. It can be applied to .

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, Machine to Machine (M2M), and MTC (Machine Type Communication) are being implemented by 5G communication technologies such as beam forming, MIMO, and array antenna. 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 the convergence of 5G technology and IoT technology.

In this way, multiple services can be provided to users in a communication system, and in order to provide such multiple services to users, a method and a device using the same that can provide each service within the same time period according to its characteristics are required. .

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

In the accompanying drawings, some components are exaggerated, omitted, or schematically shown. Additionally, the size of each component does not entirely reflect its actual size. In each drawing, identical or corresponding components are assigned the same reference numbers.

At this time, it will be understood that each block of the processing flow diagram diagrams and combinations of the flow diagram diagrams can be performed by computer program instructions. These computer program instructions can be mounted on a processor of a general-purpose computer, special-purpose computer, or other programmable data processing equipment, so that the instructions performed through the processor of the computer or other programmable data processing equipment are described in the flow chart block(s). It creates the means to perform functions. These computer program instructions may also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular manner, so that the computer-usable or computer-readable memory It is also possible to produce manufactured items containing instruction means that perform the functions described in the flowchart block(s). Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a process that is executed by the computer, thereby generating a process that is executed by the computer or other programmable data processing equipment. Instructions that perform processing equipment may also provide steps for executing the functions described in the flow diagram 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). Additionally, it should be noted that in some alternative execution examples it is possible for the functions mentioned in the blocks to occur out of order. For example, it is possible for two blocks shown in succession to be performed substantially at the same time, or it is possible for the blocks to be performed in reverse order depending on the corresponding function.

At this time, the term '~unit' used in this embodiment refers to software or hardware components such as FPGA or ASIC, and the '~unit' performs certain roles. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, 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 within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'. Additionally, components and 'parts' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Also, in the embodiment, ‘~ part’ may include one or more processors.

Wireless communication systems have moved away from providing early voice-oriented services to, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), and LTE-Advanced. It has developed into a broadband wireless communication system that provides high-speed, high-quality packet data services such as communication standards such as (LTE-A), 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e. I'm doing it. In addition, the communication standard of 5G or NR (new radio) is being created as a 5th generation wireless communication system.

In this way, in a wireless communication system including the 5th generation, at least one service among eMBB (Enhanced mobile broadband), mMTC (massive Machine Type Communications) (mMTC), and URLLC (Ultra-Reliable and low-latency Communications) can be provided to the terminal. there is. The services may be provided to the same terminal during the same time period. In an embodiment, eMBB may be a high-speed transmission of high-capacity data, mMTC may be a service that aims to minimize terminal power and connect multiple terminals, and URLLC may be a service that aims for high reliability and low delay, but is not limited thereto. The above three services may be major scenarios in LTE systems or post-LTE 5G/NR (new radio, next radio) systems. In the embodiment, the coexistence method of eMBB and URLLC, or the coexistence method of mMTC and URLLC, and a device using the same are described.

When the base station schedules data corresponding to the eMBB service to a certain terminal in a specific transmission time interval (TTI), and a situation arises in which URLLC data must be transmitted in the TTI, the eMBB data has already been scheduled. The generated URLLC data can be transmitted in the frequency band without transmitting part of the eMBB data in the frequency band being transmitted. The terminal scheduled for the eMBB and the terminal scheduled for the URLLC may be the same terminal or different terminals. In this case, the possibility of damage to the eMBB data increases because some of the eMBB data that was already scheduled and transmitted is not transmitted. Therefore, in the above case, it is necessary to determine how to process the signal received from the terminal scheduled for eMBB or the terminal scheduled for URLLC and how to receive the signal. Therefore, in the embodiment, when information according to eMBB and URLLC is scheduled by sharing part or the entire frequency band, or when information according to mMTC and URLLC are scheduled at the same time, or when information according to mMTC and eMBB are scheduled at the same time, or We describe a coexistence method between heterogeneous services that can transmit information for each service when information for eMBB, URLLC, and mMTC are scheduled simultaneously.

Hereinafter, embodiments of the present invention will be described in detail with the accompanying drawings. Additionally, when describing the present invention, if it is determined that a detailed description of a related function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. The terms described below are defined in consideration of the functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification. Hereinafter, the base station is an entity that performs resource allocation for the terminal and may be at least one of eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or node on the network. A terminal may include a UE (User Equipment), MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. In the present invention, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, hereinafter, embodiments of the present invention will be described using the LTE or LTE-A system as an example, but embodiments of the present invention can also be applied to other communication systems with similar technical background or channel type. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in this. In addition, the embodiments of the present invention may be applied to other communication systems through some modifications without significantly departing from the scope of the present invention at the discretion of a person with skilled technical knowledge.

As a representative example of the broadband wireless communication system, the LTE system adopts Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (DL), and Single Carrier Frequency Division Multiplexing (SC-FDMA) in the uplink (UL). Access) method is adopted. Uplink refers to a wireless link through which a terminal (terminal or User Equipment, UE) or Mobile Station (MS) transmits data or control signals to a base station (eNode B, or base station (BS)), and downlink is a wireless link that transmits data or control signals to a base station (eNode B, or base station (BS)). This refers to a wireless link that transmits data or control signals to this terminal. The above multiple access method usually ensures that the time-frequency resources for carrying data or control information for each user do not overlap, that is, orthogonality is maintained. To achieve this, each user's data or control information can be distinguished by allocation and operation.

The LTE system adopts the HARQ (Hybrid Automatic Repeat reQuest) method, which retransmits the data in the physical layer when a decoding failure occurs in the initial transmission. In the HARQ method, when the receiver fails to accurately decode data, the receiver transmits information (NACK; Negative Acknowledgment) informing the transmitter of the decoding failure, allowing the transmitter to retransmit the data in the physical layer. The receiver improves data reception performance by combining data retransmitted by the transmitter with data that previously failed to decode. Additionally, when the receiver accurately decodes the data, it can transmit information (ACK; Acknowledgment) indicating successful decoding to the transmitter, allowing the transmitter to transmit new data.

Figure 3a is a diagram showing the basic structure of the time-frequency domain, which is a radio resource region where the data or control channel is transmitted in the downlink in an LTE system or similar system.

(3a02)개의 OFDM 심벌이 모여 하나의 슬롯(3a06)을 구성하고, 2개의 슬롯이 모여 하나의 서브프레임(3a05)을 구성한다. 상기 슬롯의 길이는 0.5ms이고, 서브프레임의 길이는 1.0ms이다. 그리고 라디오 프레임(3a14)은 10개의 서브프레임으로 구성되는 시간영역구간이다. 주파수영역에서의 최소 전송단위는 서브캐리어(subcarrier)로서, 전체 시스템 전송 대역 (Transmission bandwidth)의 대역폭은 총

(3a04)개의 서브캐리어로 구성된다. 다만 이와 같은 구체적인 수치는 가변적으로 적용될 수 있다. Referring to Figure 3a, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol,

(3a02) OFDM symbols are gathered to form one slot (3a06), and two slots are gathered to form one subframe (3a05). The length of the slot is 0.5ms, and the length of the subframe is 1.0ms. And the radio frame 3a14 is a time domain section consisting of 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier, and the total bandwidth of the entire system transmission bandwidth is

It consists of (3a04) subcarriers. However, these specific figures may be applied variably.

(3a02)개의 연속된 OFDM 심벌과 주파수 영역에서

(3a10)개의 연속된 서브캐리어로 정의될 수 있다. 따라서, 한 슬롯에서 하나의 RB(3a08)는

개의 RE(3a12)를 포함할 수 있다. 일반적으로 데이터의 주파수 영역 최소 할당단위는 상기 RB. LTE 시스템에서 일반적으로 상기

= 7,

=12 이고,

및

는 시스템 전송 대역의 대역폭에 비례할 수 있다. 단말에게 스케줄링 되는 RB 개수에 비례하여 데이터 레이트가 증가하게 된다. LTE 시스템은 6개의 전송 대역폭을 정의하여 운영할 수 있다. 하향링크와 상향링크를 주파수로 구분하여 운영하는 FDD 시스템의 경우, 하향링크 전송 대역폭과 상향링크 전송 대역폭이 서로 다를 수 있다. 채널 대역폭은 시스템 전송 대역폭에 대응되는 RF 대역폭을 나타낸다. 아래의 표 3a는 LTE 시스템에 정의된 시스템 전송 대역폭과 채널 대역폭 (Channel bandwidth)의 대응관계를 나타낸다. 예를 들어, 10MHz 채널 대역폭을 갖는 LTE 시스템은 전송 대역폭이 50개의 RB로 구성될 수 있다. The basic unit of resources in the time-frequency domain is a resource element (3a12, RE), which can be represented by an OFDM symbol index and a subcarrier index. Resource block (3a08, Resource Block; RB or Physical Resource Block; PRB) is used in the time domain.

(3a02) consecutive OFDM symbols in the frequency domain.

It can be defined as (3a10) consecutive subcarriers. Therefore, one RB (3a08) in one slot

It may contain RE(3a12). In general, the minimum allocation unit for the frequency domain of data is the RB. In LTE systems, the above is generally

= 7;

=12,

and

may be proportional to the bandwidth of the system transmission band. The data rate increases in proportion to the number of RBs scheduled for the UE. The LTE system can be operated by defining six transmission bandwidths. In the case of an FDD system that operates by dividing downlink and uplink by frequency, the downlink transmission bandwidth and uplink transmission bandwidth may be different. The channel bandwidth represents the RF bandwidth corresponding to the system transmission bandwidth. Table 3a below shows the correspondence between system transmission bandwidth and channel bandwidth defined in the LTE system. For example, an LTE system with a 10MHz channel bandwidth may have a transmission bandwidth of 50 RBs.

[Table 3a]

In the case of downlink control information, it may be transmitted within the first N OFDM symbols within the subframe. In embodiments typically N = {1, 2, 3}. Therefore, the N value can be variably applied to each subframe depending on the amount of control information to be transmitted in the current subframe. The transmitted control information may include a control channel transmission section indicator indicating how many OFDM symbols the control information is transmitted over, scheduling information for downlink data or uplink data, and information about HARQ ACK/NACK.

In the LTE system, scheduling information for downlink data or uplink data is transmitted from the base station to the terminal through downlink control information (DCI). DCI is defined according to various formats, and depending on each format, whether it is scheduling information for uplink data (UL grant) or scheduling information for downlink data (DL grant), and whether it is compact DCI with small control information. , it can indicate whether spatial multiplexing using multiple antennas is applied, whether it is DCI for power control, etc. For example, DCI format 1, which is scheduling control information (DL grant) for downlink data, may include at least one of the following control information.

- Resource allocation type 0/1 flag: Indicates whether the resource allocation method is type 0 or type 1. Type 0 applies the bitmap method to allocate resources in RBG (resource block group) units. The basic unit of scheduling in the LTE system is the RB, which is expressed as time and frequency domain resources, and the RBG is composed of a plurality of RBs and becomes the basic unit of scheduling in the type 0 method. Type 1 allows allocation of a specific RB within the RBG.

- Resource block assignment: Indicates the RB allocated to data transmission. The resources represented are determined by system bandwidth and resource allocation method.

- Modulation and coding scheme (MCS): Indicates the modulation method used for data transmission and the size of the transport block, which is the data to be transmitted.

- HARQ process number: Indicates the HARQ process number.

- New data indicator: Indicates whether it is HARQ initial transmission or retransmission.

- Redundancy version: Indicates the redundancy version of HARQ.

- Transmit Power Control (TPC) command for PUCCH (Physical Uplink Control CHannel): Instructs a transmit power control command for PUCCH, an uplink control channel.

The DCI goes through a channel coding and modulation process and is a downlink physical control channel, PDCCH (Physical downlink control channel) (or control information, hereinafter used interchangeably) or EPDCCH (Enhanced PDCCH) (or enhanced control information, hereinafter). (Please use them interchangeably).

In general, the DCI is scrambled with a specific RNTI (Radio Network Temporary Identifier) (or terminal identifier) independently for each terminal, a CRC (cyclic redundancy check) is added, channel coded, and each is composed of an independent PDCCH. is transmitted. In the time domain, the PDCCH is mapped and transmitted during the control channel transmission period. The frequency domain mapping position of the PDCCH is determined by the identifier (ID) of each terminal, and can be transmitted spread across the entire system transmission band.

Downlink data can be transmitted on PDSCH (Physical Downlink Shared Channel), a physical channel for downlink data transmission. The PDSCH can be transmitted after the control channel transmission period, and scheduling information such as specific mapping position and modulation method in the frequency domain is determined based on the DCI transmitted through the PDCCH.

Among the control information constituting the DCI, through the MCS, the base station notifies the terminal of the modulation method applied to the PDSCH to be transmitted and the size of the data to be transmitted (transport block size; TBS). In an embodiment, the MCS may consist of 5 bits or more or fewer bits. The TBS corresponds to the size before channel coding for error correction is applied to the data (transport block, TB) that the base station wants to transmit.

The modulation methods supported by the LTE system are QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), and 64QAM, and each modulation order (Qm) corresponds to 2, 4, and 6. That is, 2 bits per symbol can be transmitted for QPSK modulation, 4 bits per symbol for 16QAM modulation, and 6 bits per symbol for 64QAM modulation. Additionally, depending on system modification, modulation methods of 256QAM or higher can be used.

Figure 3b is a diagram showing the basic structure of the time-frequency domain, which is a radio resource region where data or control channels are transmitted in the uplink in the LTE-A system.

개의 SC-FDMA 심벌이 모여 하나의 슬롯(3b06)을 구성할 수 있다. 그리고 2개의 슬롯이 모여 하나의 서브프레임(3b05)을 구성한다. 주파수영역에서의 최소 전송단위는 서브캐리어로서, 전체 시스템 전송 대역(transmission bandwidth; 3b04)은 총

개의 서브캐리어로 구성된다.

는 시스템 전송 대역에 비례하는 값을 가질 수 있다. Referring to Figure 3b, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is the SC-FDMA symbol (3b02),

SC-FDMA symbols can be gathered to form one slot (3b06). And the two slots are combined to form one subframe (3b05). The minimum transmission unit in the frequency domain is a subcarrier, and the total system transmission bandwidth (3b04) is

It consists of subcarriers.

may have a value proportional to the system transmission band.

개의 연속된 SC-FDMA 심벌과 주파수 영역에서

개의 연속된 서브캐리어로 정의될 수 있다. 따라서, 하나의 RB는

개의 RE로 구성된다. 일반적으로 데이터 혹은 제어정보의 최소 전송단위는 RB 단위이다. PUCCH의 경우 1 RB에 해당하는 주파수 영역에 매핑되어 1 서브프레임 동안 전송된다. The basic unit of resources in the time-frequency domain is a resource element (RE, 3b12), which can be defined as a SC-FDMA symbol index and subcarrier index. Resource block pair (3b08, Resource Block pair; RB pair) is used in the time domain.

In the consecutive SC-FDMA symbols and frequency domain,

It can be defined as two consecutive subcarriers. Therefore, one RB is

It consists of REs. Generally, the minimum transmission unit of data or control information is the RB unit. In the case of PUCCH, it is mapped to the frequency domain corresponding to 1 RB and transmitted for 1 subframe.

In the LTE system, PDSCH, a physical channel for downlink data transmission, or PUCCH or PUSCH, an uplink physical channel on which HARQ ACK/NACK is transmitted, corresponding to PDCCH/EPDDCH including semi-persistent scheduling release (SPS release) The timing relationship of can be defined. For example, in an LTE system operating in FDD (frequency division duplex), HARQ ACK/NACK corresponding to PDCCH/EPDCCH including PDSCH or SPS release transmitted in the n-4th subframe is transmitted to PUCCH or PUSCH in the nth subframe. can be transmitted.

In the LTE system, downlink HARQ adopts an asynchronous HARQ method in which the data retransmission time is not fixed. That is, when a HARQ NACK is received from the terminal for initial transmission data transmitted by the base station, the base station freely determines the transmission time of the retransmission data through a scheduling operation. For HARQ operation, the terminal may buffer the data determined to be an error as a result of decoding the received data and then perform combining with the next retransmitted data.

When the terminal receives a PDSCH containing downlink data transmitted from the base station in subframe n, it sends uplink control information including HARQ ACK or NACK of the downlink data to the base station through PUCCH or PUSCH in subframe n+k. send to At this time, k may be defined differently depending on the FDD or TDD (time division duplex) of the LTE system and its subframe settings. For example, in the case of the FDD LTE system, k is fixed to 4. Meanwhile, in the case of a TDD LTE system, k may change depending on subframe settings and subframe numbers. Additionally, when data is transmitted through multiple carriers, the value of k may be applied differently depending on the TDD settings of each carrier. In the case of the TDD, the k value is determined according to the TDD UL/DL settings as shown in Table 3b below.

[Table 3b]

Unlike downlink HARQ in the LTE system, uplink HARQ adopts a synchronous HARQ method with a fixed data transmission time. That is, PUSCH (Physical Uplink Shared Channel), a physical channel for uplink data transmission, PDCCH, a downlink control channel preceding it, and PHICH (Physical Hybrid Channel), a physical channel through which downlink HARQ ACK/NACK corresponding to the PUSCH is transmitted. The uplink/downlink timing relationship of the Indicator Channel can be transmitted and received according to the following rules.

When the terminal receives a PDCCH containing uplink scheduling control information transmitted from the base station in subframe n or a PHICH containing downlink HARQ ACK/NACK, it sends uplink data corresponding to the control information in subframe n+k. Transmitted via PUSCH. At this time, k may be defined differently depending on the FDD or TDD (time division duplex) of the LTE system and its settings. For example, in the case of an FDD LTE system, k may be fixed to 4. Meanwhile, in the case of a TDD LTE system, k may change depending on subframe settings and subframe numbers. Additionally, when transmitting data through multiple carriers, the value of k may be applied differently depending on the TDD settings of each carrier. In the case of the TDD, the k value is determined according to the TDD UL/DL settings as shown in Table 3c below.

[Table 3c]

And the HARQ ACK/NACK information of the PUSCH transmitted by the terminal in subframe n is transmitted from the base station to the terminal through PHICH in subframe n+k. At this time, k may be defined differently depending on the FDD or TDD of the LTE system and its settings. For example, in the case of the FDD LTE system, k is fixed to 4. Meanwhile, in the case of a TDD LTE system, k may change depending on subframe settings and subframe numbers. Additionally, when data is transmitted through multiple carriers, the value of k may be applied differently depending on the TDD settings of each carrier. In the case of the TDD, the k value is determined according to the TDD UL/DL settings as shown in Table 3d below.

[Table 3d]

The description of the wireless communication system is based on the LTE system, and the content of the present invention is not limited to the LTE system but can be applied to various wireless communication systems such as NR and 5G. In addition, when applied to other wireless communication systems in the embodiment, the k value may be changed and applied to systems that use a modulation method corresponding to FDD.

Figures 3c and 3d show how data for eMBB, URLLC, and mMTC, which are services considered in 5G or NR systems, are allocated in frequency-time resources.

Referring to FIGS. 3C and 3D, you can see how frequency and time resources are allocated for information transmission in each system.

First, Figure 3c shows data for eMBB, URLLC, and mMTC allocated in the overall system frequency band (3c00). If URLLC data (3c03, 3c05, 3c07) occurs and transmission is required while eMBB (3c01) and mMTC (3c09) are allocated and transmitted in a specific frequency band, eMBB (3c01) and mMTC (3c09) are already allocated. You can empty or transmit URLLC data (3c03, 3c05, 3c07) without transmitting. Among the above services, URLLC needs to reduce delay time, so URLLC data can be allocated (3c03, 3c05, 3c07) to a portion of the resource (3c01) to which eMBB is allocated and transmitted. Of course, if URLLC is additionally allocated and transmitted in resources to which eMBB is allocated, eMBB data may not be transmitted in overlapping frequency-time resources, and thus the transmission performance of eMBB data may be lowered. That is, in the above case, eMBB data transmission failure may occur due to URLLC allocation.

In Figure 3d, the entire system frequency band (3d00) can be divided and used to transmit services and data in each subband (3d02, 3d04, and 3d06). Information related to the subband configuration may be determined in advance, and this information may be transmitted from the base station to the terminal through higher-level signaling. Alternatively, the base station or network node may randomly divide the information related to the subband and provide services to the terminal without transmitting separate subband configuration information. In Figure 3d, subband 3d02 is used for eMBB data transmission, subband 404 is used for URLLC data transmission, and subband 3d06 is used for mMTC data transmission.

Throughout the embodiment, the length of the transmission time interval (TTI) used for URLLC transmission may be shorter than the TTI length used for eMBB or mMTC transmission. Additionally, responses to information related to URLLC can be transmitted faster than eMBB or mMTC, and thus information can be transmitted and received with low delay.

Figure 3e is a diagram showing the process in which one transport block is divided into several code blocks and a CRC is added.

Referring to FIG. 3e, a CRC (3e03) may be added to the last or first part of one transport block (3e01, transport block; TB) to be transmitted in the uplink or downlink. The CRC may have 16 bits or 24 bits, a pre-fixed number of bits, or a variable number of bits depending on channel conditions, etc., and can be used to determine whether channel coding is successful. The block (3e01, 3e03) to which TB and CRC are added can be divided into several code blocks (CB) (3e07, 3e09, 3e11, 3e13) (3e05). The code block can be divided with a predetermined maximum size. In this case, the last code block (3e13) may be smaller than the other code blocks, or 0, a random value, or 1 may be entered to have the same length as the other code blocks. I can adjust it. CRCs (3e17, 3e19, 3e21, 3e23) may be added to each of the divided code blocks (3e15). The CRC may have 16 bits, 24 bits, or a pre-fixed number of bits, and can be used to determine whether channel coding is successful. However, the CRC (3e03) added to the TB and the CRCs (3e17, 3e19, 3e21, 3e23) added to the code block may be omitted depending on the type of channel code to be applied to the code block. For example, when an LDPC code rather than a Turbo code is applied to a code block, CRCs (3e17, 3e19, 3e21, 3e23) to be inserted for each code block may be omitted. However, even when LDPC is applied, CRCs (3e17, 3e19, 3e21, 3e23) can be added to the code block as is. Additionally, even when polar codes are used, the CRC may be added or omitted.

Figure 3f is a diagram showing how the outer code is used and transmitted, and Figure 3g is a block diagram showing the structure of a communication system using the outer code.

Referring to FIGS. 3F and 3G, a method of transmitting a signal using an outer code can be seen.

In Figure 3f, after one transport block is divided into several code blocks, bits or symbols (3f04) at the same position in each code block are encoded with a second channel code to generate parity bits or symbols (3f06). It can be (3f02). After this, CRCs may be added to each code block and the parity code blocks generated by second channel code encoding (3f08, 3f10). Whether or not the CRC is added may vary depending on the type of channel code. For example, when the turbo code is used as the first channel code, the CRC (3f08, 3f10) is added, but thereafter, each code block and parity code block can be encoded with the first channel code encoding.

When an outer code is used, data to be transmitted passes through the second channel coding encoder (3g09). The channel code used for the second channel coding may be, for example, Reed-Solomon code, BCH code, Raptor code, parity bit generation code, etc. The bits or symbols that pass through the second channel coding encoder (3g09) pass through the first channel coding encoder (3g11). Channel codes used in the first channel coding include convolutional code, LDPC code, turbo code, and polar code. When these channel-coded symbols pass through the channel 3g13 and are received by the receiver, the receiver side can sequentially operate the first channel coding decoder 3g15 and the second channel coding decoder 3g17 based on the received signal. . The first channel coding decoder 3g15 and the second channel coding decoder 3g17 may perform operations corresponding to the first channel coding encoder 3g11 and the second channel coding encoder 3g09, respectively.

On the other hand, in the channel coding block diagram in which the outer code is not used, only the first channel coding encoder (3g11) and the first channel coding decoder (3g05) are used in the transceiver, respectively, and the second channel coding encoder and the second channel coding decoder are not used. No. Even when the outer code is not used, the first channel coding encoder 3g11 and the first channel coding decoder 3g05 can be configured the same as when the outer code is used.

The eMBB service described below is referred to as type 1 service, and data for eMBB is referred to as type 1 data. The first type service or first type data is not limited to eMBB and may also apply when high-speed data transmission is required or broadband transmission is performed. Additionally, URLLC service is called Type 2 service, and data for URLLC is called Type 2 data. The type 2 service or type 2 data is not limited to URLLC, but may also apply to cases where low latency is required, high reliability transmission is required, or other systems that require both low latency and high reliability. Additionally, the mMTC service is called a 3rd type service, and the data for mMTC is called 3rd type data. The third type service or third type data is not limited to mMTC and may apply to cases where low speed, wide coverage, or low power are required. Additionally, when describing an embodiment, the first type service may be understood as including or not including the third type service.

The structure of the physical layer channel used for each type to transmit the above three services or data may be different. For example, at least one of the length of the transmission time interval (TTI), the allocation unit of frequency resources, the structure of the control channel, and the data mapping method may be different.

In the above, three types of services and three types of data have been described, but there may be more types of services and corresponding data, and the content of the present invention may be applied in this case as well.

To describe the method and device proposed in the embodiment, the terms physical channel and signal in a conventional LTE or LTE-A system may be used. However, the content of the present invention can be applied to wireless communication systems other than LTE and LTE-A systems.

As described above, the embodiment defines the transmission and reception operations of the terminal and the base station for first-type, second-type, and third-type services or data transmission, and allows terminals receiving different types of services or data scheduling within the same system. suggests specific methods for operating together. In the present invention, type 1, type 2, and type 3 terminals refer to terminals that have received type 1, type 2, and type 3 services or data scheduling, respectively. In an embodiment, the first type terminal, the second type terminal, and the third type terminal may be the same terminal or may be different terminals.

In the following embodiments, at least one of the PHICH, an uplink scheduling grant signal, and a downlink data signal is referred to as the first signal. Additionally, in the present invention, at least one of an uplink data signal for uplink scheduling approval and HARQ ACK/NACK for a downlink data signal is referred to as a second signal. In an embodiment, among the signals transmitted from the base station to the terminal, if it is a signal that expects a response from the terminal, it may be the first signal, and the terminal's response signal corresponding to the first signal may be the second signal. Additionally, in an embodiment, the service type of the first signal may be at least one of eMBB, URLLC, and mMTC, and the second signal may also correspond to at least one of the services. For example, in LTE and LTE-A systems, PUCCH format 0 or 4 and PHICH can be the first signal, and the corresponding second signal can be PUSCH. Also, for example, in LTE and LTE-A systems, PDSCH may be the first signal, and PUCCH or PUSCH containing HARQ ACK/NACK information of the PDSCH may be the second signal. Therefore, in the above case, the first signal is received by the terminal, and the second signal is received by the base station. Alternatively, the downlink control signal may be the first signal, and in this case, the second signal may be a downlink data signal scheduled by the downlink control signal. In the above case, the part described in the present invention can be modified and applied to the case where the terminal receives both the first signal and the second signal.

In the following embodiment, the TTI length of the first signal is a time value related to the transmission of the first signal and may indicate the length of time for which the first signal is transmitted. In addition, in the present invention, the TTI length of the second signal is a time value related to the transmission of the second signal and can indicate the length of time for which the second signal is transmitted, and the TTI length of the third signal is the time related to the transmission of the third signal. The value may indicate the length of time for which the third signal is transmitted. In addition, in the present invention, the second signal transmission timing is information about when the terminal transmits the second signal and when the base station receives the second signal, and can be referred to as the second signal transmission and reception timing.

Additionally, in the following embodiment, assuming that when the base station transmits the first signal in the nth TTI and the terminal transmits the second signal in the n+kth TTI, the base station informs the terminal of the timing for transmitting the second signal. This is the same as telling the value of k. Alternatively, assuming that when the base station transmits the first signal in the nth TTI and the terminal transmits the second signal in the n+4+ath TTI, the fact that the base station informs the terminal of the timing to transmit the second signal in the above refers to the offset It is the same as telling the value a. Instead of n+4+a, the offset can be defined in various ways, such as n+3+a and n+5+a, and the n+4+a value mentioned in the present invention can also be defined in various ways. can be defined.

Although the content of the present invention is explained based on the FDD LTE system, it can also be applied to TDD systems and NR systems.

Hereinafter, in the present invention, higher-order signaling is a signal transmission method in which a signal is transmitted from a base station to a terminal using a downlink data channel of the physical layer, or from a terminal to a base station using an uplink data channel of the physical layer, and is called RRC signaling or PDCP signaling. , or may be referred to as a MAC control element (MAC CE).

Although the present invention describes a method of determining the timing for transmitting a second signal after a terminal or base station receives a first signal, the method of transmitting the second signal may be possible in various ways. For example, after the terminal receives PDSCH, which is downlink data, the timing of sending HARQ ACK/NACK information corresponding to the PDSCH to the base station follows the method described in the present invention, but selection of the PUCCH format to be used, selection of PUCCH resources, or The method of mapping HARQ ACK/NACK information to PUSCH can follow the conventional LTE method.

In the present invention, normal mode refers to a mode that uses the first and second signal transmission timings used in conventional LTE and LTE-A systems, and in the normal mode, a signal of about 3 ms including TA is transmitted. It is possible to secure processing time. For example, in an FDD LTE system operating in normal mode, the second signal in response to the first signal received by the terminal in subframe n is transmitted by the terminal in subframe n+4.

Meanwhile, in the present invention, the latency reduction mode is a mode that makes it possible to make the transmission timing of the second signal with respect to the first signal faster than or equal to the normal mode, and can reduce the delay time. In delay reduction mode, timing can be controlled in various ways.

In the present invention, the explanation will be based on the case where the length of the transmission time interval (TTI) used in the normal mode and the reduced delay mode is the same. However, the content of the present invention can be applied even when the length of TTI in normal mode and TTI in delay reduction mode are different.

One of the important criteria for cellular wireless communication system performance is packet data latency. For this purpose, in the LTE system, signals are transmitted and received in subframe units with a transmission time interval (TTI) of 1 ms. The LTE system operating as described above can support UEs (shortened-TTI/shorter-TTI UE) with a transmission time interval shorter than 1 ms. Shortened-TTI terminals are expected to be suitable for services such as Voice over LTE (VoLTE) services and remote control where latency is important. In addition, shortened-TTI terminals are expected to be a means of realizing mission-critical Internet of Things (IoT) based on cellular.

In the current LTE and LTE-A systems, the base station and terminal are designed to transmit and receive in subframe units with a transmission time interval of 1ms. In an environment where there are base stations and terminals operating with a transmission time interval of 1ms, in order to support shortened-TTI terminals operating with a transmission time interval shorter than 1ms, transmission and reception operations that are differentiated from general LTE and LTE-A terminals are defined. Needs to be. Therefore, the present invention can be applied to a specific method for operating general LTE and LTE-A terminals and shortened-TTI terminals together within the same system. In the present invention, the delay reduction mode may be an operation of transmitting and receiving data using shortened-TTI. Additionally, in the present invention, shortened-TTI, shorter-TTI, shortened TTI, shorter TTI, short TTI, sTTI, mini-slot, and sub-slot may have the same meaning and may be used interchangeably. In the present invention, a shortened TTI or mini-slot may be a unit transmitted with OFDM symbols less than 14 or 7. Additionally, in the present invention, normal-TTI, normal TTI, subframe TTI, legacy TTI, and slot TTI have the same meaning and are used interchangeably. In the present invention, the downlink control signal for shortened-TTI can be referred to as sPDCCH and can be used interchangeably with PDCCH for shortened-TTI. In the present invention, the downlink data signal for shortened-TTI can be referred to as sPDSCH and can be used interchangeably with PDSCH for shortened-TTI. Additionally, in the present invention, the uplink data signal for shortened-TTI can be referred to as sPUSCH and can be used interchangeably with the PUSCH for shortened-TTI. Additionally, in the present invention, the uplink control signal for shortened-TTI can be called sPUCCH and can be used interchangeably with PUCCH for shortened-TTI.

Although the present invention describes a transmission and reception method for a system using shortened TTI, it can also be applied to a transmission and reception method that transmits uplink transmission or downlink HARQ feedback in a shorter time than conventional LTE with a 1ms TTI length for the purpose of delay reduction. This will be obvious to anyone with general wireless communication knowledge.

The present invention has been mainly explained based on the case where the base station sets the delay reduction mode for the terminal, but it can be applied even without the delay reduction mode setting.

[Example 3-1]

Embodiment 3-1 is a method in which the base station notifies the terminal that it operates in delay reduction mode through higher-order signaling, and the terminal determines and operates the second signal transmission and resource and power adjustment timing according to the settings of the higher-order signaling. This will be explained with reference to Figure 3h.

The base station sets the delay reduction mode to the terminal through higher-level signaling (3h02). The higher level signaling may be RRC signaling or may be set through a MAC control element. The base station may transmit transmission timing information of the second signal following the first signal to the terminal in the higher-order signaling (3h04). Afterwards, the terminal transmits the second signal at a predetermined timing, and the base station receives the second signal at the terminal's second signal transmission timing and performs decoding (3h06). As already described above, assuming that when the base station transmits the first signal in the nth TTI and the terminal transmits the second signal in the n+kth TTI, the timing at which the base station transmits the second signal to the terminal is as follows. Telling is the same as telling the value of k. Alternatively, assuming that when the base station transmits the first signal in the nth TTI and the terminal transmits the second signal in the n+4+ath TTI, the fact that the base station informs the terminal of the timing to transmit the second signal in the above refers to the offset It is the same as telling the value a. The offset may be defined in various ways, such as n+3+a, n+5+a, etc. instead of n+4+a.

The terminal receives the k value or offset value a for the second signal transmission timing from the base station through higher-level signaling (3h04). Afterwards, when the terminal receives the first signal at the nth TTI, it transmits the corresponding second signal to the base station at the n+kth TTI or n+4+a TTI (3h06).

When the base station determines the value k or the offset value a for the second signal transmission timing, the decision may be made by referring to the terminal capability notified by the terminal to the base station.

k or offset a indicated through the higher-level signaling may not be a single value but a set of multiple values. The terminal can use one value from the set of k or offset a delivered through higher-order signaling to determine the second signal transmission timing. A method of selecting one value from the set may be based on a specific bit of control information DCI transmitted together when the first signal is transmitted from the base station, or the terminal may select it arbitrarily.

In addition, the information provided through the higher-level signaling may be able to deliver a set of k values or offsets a according to specific TDD UL/DL settings and TTI index values in consideration of the TDD system.

For example, if higher-order signaling for setting the delay reduction mode and transmitting parameters is delivered to the MAC control element (MAC CE), the base station and the terminal will be able to know when the higher-level signaling is applied. Therefore, if the base station sets the delay reduction mode as a MAC control element to the terminal in subframe n, for example, it may be possible to apply the delay reduction mode starting from subframe n+6.

Although the operation of the terminal and base station has been described based on the delay reduction mode, it may be possible to apply it even if it is not the delay reduction mode. For example, in a 5G communication system, it may be applicable when transmitting the second signal transmission timing for the first signal to the terminal.

[Example 3-2]

Embodiment 3-2 is a method of determining the timing at which the second signal is transmitted from the terminal or the timing at which power control begins through downlink control information (DCI) by the base station to the terminal, referring to FIG. 3I. to provide.

The base station sets the delay reduction mode to higher level signaling for the terminal (3i01). The base station determines the timing at which the terminal will transmit the second signal, and transmits the timing using a specific x bit in the DCI transmitted when transmitting the first signal to the terminal (3i05). The number of bits x can be set to 1, 2, or 3. The size of the x bits and the transmission timing indicated by the information may be pre-assigned in the higher-order signaling settings (3i03). That is, the k value or offset value a indicated by HARQ timing bits 00, 01, 10, and 11 in the table below can be delivered to the terminal through higher-level signaling. At the determined second signal transmission timing, the base station receives and decodes the second signal.

After decoding the downlink control signal, the terminal checks the specific x bit in the DCI and finds the k value or offset value a for the second signal transmission timing from the specific x bit value. Afterwards, when the terminal receives the first signal at the n-th TTI, it transmits the corresponding second signal to the base station at the n+k-th TTI or n+4+a-th TTI (3i05, 3i07).

For example, when x is 2, that is, when 2 bits of DCI are information for the second signal transmission timing, the k value for the second signal transmission timing can be provided as follows.

Alternatively, the offset value a for the second signal transmission timing may be reported as follows.

When the base station determines the value k or the offset value a for the second signal transmission timing, the decision may be made by referring to the terminal capability notified by the terminal to the base station.

[Example 3-2-1]

In the 3-2-1 embodiment, when the base station determines the timing at which the second signal is transmitted from the terminal through DCI to the terminal or the timing at which power control is started, One of the HARQ timing values always provides a method of using a fixed value as the second signal transmission timing with reference to FIG. 3n. The fixed value may be the default timing.

The base station transmits to the terminal a set of values that can be the k value or the offset value a for second signal transmission through higher-level signaling (3n03). The base station determines the timing at which the terminal will transmit the second signal, and transfers the timing using a specific Check (3n05). The number of bits x can be set to 1, 2, or 3. The size of the x bits and the transmission timing indicated by the information may be pre-assigned in the higher-order signaling settings (3i03). That is, the k value or offset value a indicated by HARQ timing bits 01, 10, and 11 in the table below can be delivered to the terminal through higher-level signaling. However, the specific value of the HARQ timing bits is not transmitted from higher-level signaling, but may be pre-arranged between the base station and the terminal, or may be transmitted in the SIB. For example, when the HARQ timing bits indicate 00, the k value or offset a value causes transmission and reception of the second signal at the timing transmitted from the SIB (3n09). The timing delivered in the SIB may be called default timing. On the other hand, when the HARQ timing bits are 01, 10, or 11 instead of 00, one of the values transmitted from higher-level signaling is used (3n11). At this time, after decoding the downlink control signal, the terminal checks the specific x bit in the DCI and finds the k value or offset value a for the second signal transmission timing from the specific x bit value. Afterwards, when the terminal receives the first signal at the n-th TTI, it transmits the corresponding second signal to the base station at the n+k-th TTI or n+f+a-th TTI (3n11). The f may be a reference value for an offset, and the f value can be delivered to the terminal through higher-order signaling or SIB.

For example, when x is 2, that is, when 2 bits of DCI are information for the second signal transmission timing, the k value for the second signal transmission timing can be provided as follows.

Alternatively, the offset value a for the second signal transmission timing may be reported as follows.

The offset can be used to find the second signal transmission timing by adding it to the default timing known to the terminal through SIB or the like.

When the base station determines the value k or the offset value a for the second signal transmission timing, the decision may be made by referring to the terminal capability notified by the terminal to the base station.

[Example 3-2-2]

In the 3-2-2 embodiment, when the base station determines the timing at which the second signal is transmitted from the terminal through DCI to the terminal or the timing at which power control begins, the detected DCI is specified. In the case of format or when there is no bit field related to the second signal transmission timing in DCI, a method of always using a fixed value as the second signal transmission timing is provided with reference to FIG. 3O. The fixed value may be the default timing.

The base station transmits the k value of the default timing for the second signal transmission in the SIB or the reference timing for using the offset a to the terminal, and sets the values that can be the k value or the offset value a for the second signal transmission through higher-order signaling. The set is delivered to the terminal (3o01). The base station determines the timing at which the terminal will transmit the second signal, and if the timing is not the default timing, the timing is transmitted using a specific x bit in the DCI transmitted when transmitting the first signal to the terminal. If the timing is the default timing, it is sent as a DCI without a timing bit field. If the default timing above is one of the timing values delivered through higher-level signaling set by the base station to the terminal, it can be sent through DCI with a timing bit field. The terminal attempts DCI detection and checks whether a timing bit field exists in the detected DCI (3o03). If a timing bit field exists in the DCI (3o07), at this time, after decoding the downlink control signal, the terminal checks the specific x bit in the DCI, and determines the k value for second signal transmission timing from the specific x bit value. Or, find the offset value a and transmit the second signal at the corresponding timing (3o07). Afterwards, when the terminal receives the first signal at the nth TTI, it transmits the corresponding second signal to the base station at the n+kth TTI or n+f+a TTI (3o07). The f may be a reference value for an offset, and the f value can be delivered to the terminal through higher-order signaling or SIB. Meanwhile, the terminal attempts DCI detection, checks whether a timing bit field exists in the detected DCI (3o03), and if the timing bit field does not exist in the DCI (3o05), sends the second signal at the default timing transmitted from the SIB. Send (3o05).

[Example 3-2-3]

In the 3-2-3 embodiment, when the base station determines the timing at which the second signal is transmitted from the terminal or the timing at which power control begins through DCI to the terminal, the DCI is used in a specific search area. When detected, a method of always using a fixed value as the second signal transmission timing is provided with reference to Figure 3p. The fixed value may be the default timing.

The base station transmits the k value of the default timing for the second signal transmission in the SIB or the reference timing for using the offset a to the terminal, and sets the values that can be the k value or the offset value a for the second signal transmission through higher-order signaling. Deliver the set to the terminal (3p01). The base station promises a specific search area with the terminal so that the first signal to the second signal to be transmitted at default timing is mapped to the specific search area. The base station determines the timing at which the terminal will transmit the second signal, and if the timing is not the default timing, the timing is transmitted using a specific x bit in the DCI transmitted when transmitting the first signal to the terminal, and the DCI is The DCI is mapped to a search area other than the specific search area for the default timing, and if the timing is the default timing, the DCI is mapped to the specific search area for the default timing. The terminal attempts DCI detection and checks whether DCI is detected in a specific detection area for default timing (3p03). If the DCI is detected in a search area other than the specific search area for the default timing (3p07), at this time, the terminal checks the specific x bit in the DCI after decoding the downlink control signal, and determines the 2 Find the k value or offset value a for the signal transmission timing and transmit the second signal at the corresponding timing (3p07). Afterwards, when the terminal receives the first signal at the n-th TTI, it transmits the corresponding second signal to the base station at the n+k-th TTI or n+f+a-th TTI (3p07). The f may be a reference value for an offset, and the f value can be delivered to the terminal through higher-order signaling or SIB. Meanwhile, the terminal attempts to detect DCI, checks whether DCI is detected in a specific detection area for default timing (3p03), and if DCI is detected in a specific detection area for default timing (3p05), the default timing transmitted from SIB Transmits the second signal (3p05).

[Example 3-3]

Embodiment 3-3 describes a method of sending HARQ ACK/NACK information for downlink data transmitted in multiple TTIs from one TTI to the uplink as HARQ timing may vary, with reference to FIG. 3j.

In a situation where downlink data is delivered to a terminal in which the delay reduction mode is set (3j02) as in the 3-1 or 3-2 embodiment, the downlink corresponding to HARQ ACK/NACK that must be delivered to the base station at a specific TTI n It may be possible to use different methods for sending uplink control signals when the number of link data is one or multiple. For example, when using delay reduction mode in an LTE system, when the number of PDSCHs corresponding to HARQ ACK/NACK to be sent in subframe n is one, PUCCH format 1a or format 1b is used, and two or more PDSCHs previously received are used. When transmitting HARQ ACK/NACK, it may vary depending on whether HARQ-ACK bundling or HARQ-ACK multiplexing is set. The HARQ-ACK bundling and multiplexing settings or PUCCH format selection can be set as higher-level signaling from the base station to the terminal (3j04).

If HARQ-ACK bundling is set when transmitting HARQ ACK/NACK corresponding to two or more PDSCHs, ACK is made only when all codewords corresponding to the two PDSCHs are ACK, and in other cases, NACK is set, up to Generates two HARQ ACK/NACK information. The generated HARQ ACK/NACK information may be transmitted using PUCCH format 1a or 1b. For example, if the PDSCHs transmitted in two or more subframes all contain only one codeword, the HARQ ACK/NACK information generated through HARQ-ACK bundling will be 1 bit, which is PUCCH format 1a. is transmitted. Also, for example, if the PDSCHs transmitted in two or more TTIs include only two codewords, the HARQ ACK/NACK information generated through HARQ-ACK bundling will be 2 bits, which is It is transmitted in PUCCH format 1b.

와 PUCCH 포맷 1b에 사용되는 2비트 b(0) 및 b(1)이 결정될 수 있다. 상기 i는 0 또는 1 또는 2 또는 3인 정수가 될 수 있다. 상기 단말이 보내야하는 HARQ ACK 정보 비트수는 본 발명의 제3-4실시예 등에서 설명하는 방법과 같이 DCI 등에서, 예를 들어 DAI 값으로, 전달될 수 있을 것이다 (3j06). If HARQ-ACK multiplexing is set when transmitting HARQ ACK/NACK corresponding to two or more PDSCHs, ACK information is generated only when it is ACK for all codewords in each PDSCH, and in other cases, NACK is generated. Therefore, for example, when considering PDSCH transmitted in up to M TTIs, M bits of HARQ ACK/NACK information are generated. The generated M-bit HARQ ACK/NACK information may be delivered to the base station using the PUCCH format 1b with channel selection method or PUCCH format 3. The PUCCH format 1b with channel selection is the same as Table 3e-Table 3j below, and PUCCH transmission resources according to M HARQ ACK/NACK information.

and 2 bits b(0) and b(1) used in PUCCH format 1b can be determined. The i may be an integer of 0, 1, 2, or 3. The number of HARQ ACK information bits to be sent by the terminal may be transmitted in DCI, for example, as a DAI value, as described in the 3-4 embodiment of the present invention (3j06).

[Table 3e] PUCCH format 1b with channel selection method when M=2

[Table 3f] PUCCH format 1b with channel selection method when M=3

[Table 3g] PUCCH format 1b with channel selection method when M=4

[Table 3h] PUCCH format 1b with channel selection method when M=2

[Table 3i] PUCCH format 1b with channel selection method when M=3

[Table 3j] PUCCH format 1b with channel selection method when M=4

를 결정하는 방법은 다양한 방법으로 가능할 것이다. 예를 들어, TTI n에 전송될 PUCCH는 n-1, n-2, n-3, n-4 TTI에서 전송된 PDSCH의 HARQ-ACK을 포함해야 한다면, M=4가 될 것이며, k1=4, k2=3, k3=2, k4=1이라고 하기로 하자.

는 TTI n-ki에서 전송된 PDSCH의 제어채널이 매핑된 첫번째 CCE의 번호이다.

라고 할 때, c는 0, 1, 2, 3 중에서

를 만족하는 수이다. 이 때, PUCCH 자원

은 하기와 같이 정해질 수 있다.From the above, PUCCH resource person

There are various ways to determine . For example, if the PUCCH to be transmitted in TTI n must include the HARQ-ACK of the PDSCH transmitted in n-1, n-2, n-3, and n-4 TTIs, M = 4, and k1 = 4. , let us say k2=3, k3=2, k4=1.

is the number of the first CCE to which the control channel of the PDSCH transmitted in TTI n-ki is mapped.

When saying, c is 0, 1, 2, 3.

It is a number that satisfies . At this time, PUCCH resources

can be determined as follows.

는 상위 시그널링으로 단말에게 설정될 수 있다. From above

Can be set to the terminal through higher-level signaling.

In the above example, the PUCCH format 1a or 1b or 1b with channel selection method was described to send HARQ ACK/NACK information for downlink data transmitted in multiple TTIs to the uplink in one TTI, and in the following, PUCCH format 3 or Explain how to use 4 or 5. When transmitting an uplink PUCCH or PUSCH, the terminal determines the number of HARQ ACK information to be transmitted. The above determination may be made by referring to the DAI value transmitted in control information during previous downlink data transmission or PUSCH scheduling. If the HARQ ACK/NACK information is configured from the HARQ-ACK information of the earliest delivered PDSCH to the HARQ-ACK information of the most recently delivered PDSCK, it is assumed that the number of HARQ ACK/NACK bits determined from the DAI value, etc. The information can be transmitted using PUCCH format 3, 4, or 5. Using the PUCCH format 3, 4, or 5 can be set as higher-order signaling to a terminal set in delay reduction mode (3j04). Additionally, the PUCCH format 3, 4, or 5 may be defined in the conventional LTE-A or LTE-A pro. When configuring HARQ ACK/NACK information from the HARQ-ACK information of the earliest delivered PDSCH to the HARQ-ACK information of the most recently delivered PDSCH, when HARQ-ACK bundling is set, the codewords of the PDSCH transmitted at once are It can be set to ACK only when all are ACK.

[Example 3-4]

Embodiment 3-4 describes a method of setting the DAI (downlink assignment index) value so that the base station and the terminal know the same amount of HARQ ACK/NACK information to be transmitted by the delay reduction mode terminal.

값으로 상기 제어정보에 포함하여 단말에게 전송한다. When transmitting control information for uplink scheduling, such as DCI format 0 or 4, to the terminal for uplink scheduling, the base station determines the amount of HARQ ACK/NACK information to be transmitted simultaneously when the uplink transmission is performed.

The value is included in the control information and transmitted to the terminal.

값을 상기 제어정보에 포함하여 단말에게 전송한다. 일례로 TTI n에서 HARQ ACK/NACK을 전송해야하는 PDSCH가 처음 전송하는 경우의 제어신호에서는 1에 해당하는

값을 포함하는 것이 가능하며, TTI n에서 HARQ ACK/NACK을 전송해야하는 PDSCH가 두 번째에 해당하는 경우의 제어신호에서는 2에 해당하는

값을 포함하는 것이 가능할 것이다. In addition, when the base station transmits control information to the terminal for downlink data transmission, the downlink transmission corresponds to the number of HARQ ACK/NACKs to be transmitted by the terminal in serving cell c.

The value is included in the control information and transmitted to the terminal. For example, when the PDSCH that needs to transmit HARQ ACK/NACK in TTI n is first transmitted, the control signal corresponding to 1

It is possible to include a value, and in the case where the PDSCH that needs to transmit HARQ ACK/NACK in TTI n is the second, the control signal corresponds to 2.

It would be possible to include values.

값과

값이 가리키는 하향링크 데이터 전송의 수는 하기 표와 같이 정해질 수 있다. 상기 표와 같이 정해지는 값은 하나의 일례일 뿐이며, 2비트 이상의

값과

값에 대해서도 쉬운 변형으로 적용하는 것이 가능할 것이다. 예를 들어, DAI 정보를 위해 DCI에서 2비트가 아닌 3비트 혹은 4비트를 사용하는 것도 가능할 수 있을 것이다.remind

value and

The number of downlink data transmissions indicated by the value can be determined as shown in the table below. The value determined as in the table above is only one example, and is 2 bits or more.

value and

It would be possible to apply an easy transformation to the value as well. For example, it may be possible to use 3 or 4 bits rather than 2 bits in DCI for DAI information.

[Example 3-5]

Embodiment 3-5 describes a method of determining the timing at which the second signal is transmitted from the terminal to the base station using the absolute value of the TA of the terminal set in delay reduction mode with reference to FIG. 3K.

The base station sets the delay reduction mode for the terminal (3k02) and calculates the absolute value of the TA of the terminal (3k04). When the terminal initially connects, the base station can calculate the absolute value of TA by adding or subtracting the amount of change in the TA value transmitted through higher-level signaling from the TA value first transmitted to the terminal in the random access step. The terminal can also calculate the absolute value of TA in the same way as the base station method. Alternatively, the terminal can calculate the absolute value of TA by subtracting the start time of the nth TTI received by the terminal from the start time of the nth TTI transmitted. Hereinafter, in the present invention, the absolute value of TA may be referred to as NTA.

As described above, the base station and the terminal can know the NTA, and can connect the NTA to the second signal transmission timing using arbitrary mapping. Therefore, using the mapping relationship, the base station and the terminal can find the second signal transmission timing using NTA (3k06), and at the second signal transmission timing, the terminal transmits the second signal (3k08), and the base station The transmitted second signal can be received and decoded (3k08). For example, the NTA and the second signal transmission timing k can be found by the method shown in Table 3 below.

[Table 3k]

In Table 3k above, the equal sign of the inequality sign can be excluded or added, and the k values x and y according to NTA can be set by the base station to the terminal in the delay reduction mode setting, or x is fixed to 4 and y is 2 or 3. It may be fixed or may vary depending on settings. The above example is only one example, and the k value according to the NTA value may be determined in various ways. Additionally, it is obvious that the offset a can be determined instead of the k value for indicating the second signal transmission timing. Additionally, it may be determined based on absolute time length instead of NTA, which is the standard. Additionally, it can be easily determined as a modification of the present invention that the value of k or a is changed according to the amount of change in TA value over a given period of time instead of based on NTA.

[Example 3-6]

Embodiment 3-6 explains the delay reduction mode and the operation method of the terminal in which CA is set to one or more carriers.

A terminal configured with delay reduction mode and CA with one or more carriers, or a terminal configured with delay reduction mode, performs blind decoding of PDCCH or EPDCCH only in the primary cell. Alternatively, when setting the delay reduction mode, if the setting is to transmit the HARQ ACK/NACK information of the PDSCH transmitted in subframe n in subframe n+2, the terminal can be restricted to perform blind decoding of the PDCCH or EPDCCH only in the primary cell. there is.

[Example 3-7]

Embodiment 3-7 explains how a terminal supporting the delay reduction mode uses different DCI detection methods depending on the delay reduction mode setting. Here, delay reduction mode may mean transmission using shortened TTI.

When detecting DCI, the terminal performs decoding assuming an already determined DCI size. The DCI may include bits for the HARQ process number. For example, if there are 8 HARQ processes for a terminal operating in normal mode in an FDD system, a 3-bit HARQ process number is required when scheduling for the terminal. There may be a bit field for On the other hand, a terminal operating with shortened TTI may require a greater number of HARQ processes. For example, a terminal in shortened TTI mode operating with 2 or 3 symbols may have 16 HARQ processes, and 4 bits are required to transmit this information in DCI. If the base station decides to share the HARQ process numbers of normal mode and shortened TTI mode, 16 HARQ processes can be used in normal mode, and therefore a 4-bit HARQ process bit field is also required in DCI transmitted in normal mode. do. Therefore, the terminal must determine that the number of HARQ process bits included in the DCI transmitted in normal mode is different when the delay reduction mode is set and shortened TTI operation is performed and when the delay reduction mode is not set and shortened TTI operation is not performed. .

When the base station transmits DCI to the terminal for data transmission scheduling, it includes an x-bit HARQ process information bitfield if the delay reduction mode is set, and a y-bit HARQ process information bitfield if the delay reduction mode is not set. I order it. The x and y may be the same, and may generally be different. For example, x may be set to 3 bits, and y may be set to 4 bits.

When detecting DCI for data transmission, the terminal performs DCI decoding assuming an x-bit HARQ process information bit field if the delay reduction mode is set, and if the delay reduction mode is not set, a y-bit HARQ process information bit field. DCI decoding is performed assuming the field. The x and y may be the same, and may generally be different. For example, x may be set to 3 bits, and y may be set to 4 bits.

In this embodiment, only the bit field for HARQ process number information is described, but the length or interpretation method of other information in DCI may also be changed depending on the delay reduction mode setting.

In order to perform the above embodiments of the present invention, the transmitting unit, receiving unit, and processing unit of the terminal and the base station are shown in FIGS. 3L and 3M, respectively. From the 3-1 embodiment to the 3-6 embodiment, a transmission and reception method between the base station and the terminal is shown to determine the transmission and reception timing and terminal transmission power of the second signal and perform the corresponding operation, and the base station to perform this and the receiving unit, processing unit, and transmitting unit of the terminal must each operate according to the embodiment.

Specifically, Figure 3l is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention. As shown in Figure 3l, the terminal of the present invention may include a terminal receiving unit 3l00, a terminal transmitting unit 3l04, and a terminal processing unit 3l02. The terminal receiver 3l00 and the terminal transmitter 3l04 may be collectively referred to as the transmitter/receiver in the embodiment of the present invention. The transceiver unit can transmit and receive signals to and from the base station. The signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. Additionally, the transceiver may receive a signal through a wireless channel and output it to the terminal processing unit 3l02, and transmit the signal output from the terminal processing unit 3l02 through a wireless channel. The terminal processing unit 3102 can control a series of processes so that the terminal can operate according to the embodiment of the present invention described above. For example, the terminal receiver 3100 may receive a signal including second signal transmission timing information from the base station, and the terminal processor 3102 may be controlled to interpret the second signal transmission timing. Afterwards, the terminal transmitter 3104 transmits the second signal at the above timing.

Figure 3M is a block diagram showing the internal structure of a base station according to an embodiment of the present invention. As shown in Figure 3M, the base station of the present invention may include a base station receiving unit 3m01, a base station transmitting unit 3m05, and a base station processing unit 3m03. The base station receiving unit 3m01 and the base station transmitting unit 3m05 may be collectively referred to as the transmitting and receiving unit in the embodiment of the present invention. The transmitting and receiving unit can transmit and receive signals to and from the terminal. The signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. Additionally, the transceiver may receive a signal through a wireless channel and output it to the base station processing unit 3m03, and transmit the signal output from the terminal processing unit 3m03 through a wireless channel. The base station processing unit 3m03 can control a series of processes so that the base station can operate according to the embodiment of the present invention described above. For example, the base station processing unit 3m03 may determine the second signal transmission timing and control the generation of the second signal transmission timing information to be delivered to the terminal. Thereafter, the base station transmitter 3m05 transmits the timing information to the terminal, and the base station receiver 3m01 receives the second signal at the timing.

Additionally, according to an embodiment of the present invention, the base station processing unit 3m03 may control to generate downlink control information (Downlink Control Information, DCI) including the second signal transmission timing information. In this case, the DCI may indicate that it is the second signal transmission timing information.

Meanwhile, the embodiments of the present invention disclosed in the specification and drawings are merely provided as specific examples to easily explain the technical content of the present invention and to facilitate understanding of the present invention, and are not intended to limit the scope of the present invention. In other words, it is obvious to those skilled in the art that other modifications based on the technical idea of the present invention can be implemented. Additionally, each of the above embodiments can be operated in combination with each other as needed. For example, Embodiments 3-1, 3-2, and parts of Embodiment 3-3 of the present invention can be combined to operate the base station and the terminal. In addition, although the above embodiments were presented based on the LTE/LTE-A system, other modifications based on the technical idea of the above embodiments may be implemented in other systems such as 5G and NR systems.

<Example 4>

Wireless communication systems to date have mainly evolved with the goal of improving transmission speed and transmission efficiency. On the other hand, the 5G mobile communication requirements recently presented by ITU-R include not only eMBB (enhanced mobile broadband), a service that requires high transmission speeds, but also URLLC (Ultra Reliability and Low Latency), a service that requires short transmission delays. Communication) and mMTC (Massive Machine Type Communication), a service that requires high connection density, are specified to be supported. To this end, various technologies are being discussed, such as signal transmission technology using new waveforms, non-orthogonal multiple access technology, and large-scale multiple antenna technology using ultra-high frequency bands.

Figure 4a is a diagram showing an example in which three 5G services, namely eMBB (4a-01), URLLC (4a-02), and mMTC (4a-03), are multiplexed and transmitted in one system.

5G aims to be a single wireless access technology that accommodates all three defined service scenarios, and its philosophy is to build a flexible system that is different from the conventional one. For example, in order to satisfy different frequency bands and requirements, scalability can be provided to numerology such as subcarrier spacing when generating OFDM signals to provide simultaneous services. Alternatively, you can set the delay time and requirements to suit each service by adjusting the TTI according to the situation. Figure 4a shows that eMBB (4a-01), URLLC (4a-02), and mMTC (4a-03) are each set to different TTIs (4a-04). In addition, taking future compatibility into consideration, we aim to design services designed in the future so that they are not subject to constraints limited by the current system. In order to build such a flexible system, a technical approach to 5G is needed to exclude as much as possible the various always-on signals that existed in conventional LTE or the fixed signals transmitted across the entire system band.

In LTE, PDCCH, one of the physical channels that transmit downlink control signals, that is, DCI (Downlink Control Information), is transmitted every subframe across the entire system band. And CRS (Cell-specific Reference Signal) is used as a reference signal to decode the PDCCH. CRS is a representative always-on signal that is always transmitted regardless of the presence or absence of downlink traffic. In other words, because the structure of the PDCCH currently used in LTE cannot be set flexibly, if the existing PDCCH is used as is in the 5G system, there will be difficulties in supporting various services according to requirements or securing future compatibility.

The downlink control channel that exists in LTE will be explained in more detail. FIG. 4b is a diagram showing PDCCH (4b-01) and Enhanced PDCCH (EPDCCH, 4b-02), which are downlink physical channels through which LTE DCI is transmitted. According to Figure 4b, PDCCH (4b-01) is time-multiplexed with PDSCH (4b-03), a data transmission channel, and transmitted over the entire system bandwidth. The area of PDCCH (4b-01) is expressed by the number of OFDM symbols, which is indicated to the terminal as a CFI transmitted through PCFICH (Physical Control Format Indicator Channel). By allocating the PDCCH (4b-01) to the OFDM symbol that comes at the beginning of the subframe, the UE can decode the downlink scheduling assignment as quickly as possible, thereby reducing the decoding delay for the DL-SCH (Downlink Shared Channel), i.e. There is an advantage in reducing the overall downlink transmission delay.

DCI transmitted through PDCCH (4b-01) includes the following.

- Downlink scheduling assignment: PDSCH resource designation, transmission format, HARQ information, spatial multiplexing-related control information

- Uplink scheduling grant: PUSCH resource designation, transmission format, HARQ information, PUSCH power control

- Power control command for a set of terminals

Different control information generally has different DCI message sizes and is classified into different DCI formats. To briefly introduce the DCI format, downlink scheduling allocation information is transmitted in DCI format 1/1A/1B/1C/1D/2/2A/2B/2C, and uplink scheduling approval is transmitted in DCI format 0/4. And the power control command is transmitted in DCI format 3/3A. One PDCCH (4b-01) carries one message in one of the DCI formats. In general, since multiple terminals are scheduled simultaneously on the downlink and uplink, each scheduling message is transmitted on each PDCCH (4b-01), so multiple PDCCH (4b-01) transmissions occur simultaneously.

A CRC (Cyclic Redundancy Check) is attached to the DCI message payload, and the CRC is scrambled with an RNTI (Radio Network Temporary Identifier) corresponding to the terminal's identity. Different RNTIs are used depending on the purpose of the DCI message, for example, UE-specific data transmission, power control command, or random access response. In other words, the RNTI is not transmitted explicitly but is transmitted included in the CRC calculation process. When receiving a DCI message transmitted on the PDCCH, the terminal checks the CRC using the allocated RNTI, and if the CRC check result is correct, it can know that the message was sent to the terminal.

Resource allocation of the PDCCH (4b-01) is based on CCE (Control-Channel Element), and one CCE consists of 9 REGs (Resource Element Groups), that is, a total of 36 REs (Resource Elements). The number of CCEs required for a specific PDCCH (4b-01) can be 1, 2, 4, or 8, which varies depending on the channel coding rate of the DCI message payload. In this way, different numbers of CCEs are used to implement link adaptation of PDCCH (4b-01). The terminal must detect a signal without knowing information about the PDCCH (4b-01), and in LTE, a search space representing a set of CCEs is defined for blind decoding. The search space consists of a plurality of sets at the aggregation level of each CCE, and this is not explicitly signaled but is implicitly defined through a function by terminal identity and subframe number. Within each subframe, the terminal performs decoding on all possible PDCCHs (4b-01) that can be created from CCEs in the set search space, and processes information declared to be valid for the terminal through CRC confirmation. The search space is classified into a terminal-specific search space and a common search space. A certain group of UEs or all UEs can search the common search space of the PDCCH (4b-01) to receive cell common control information such as dynamic scheduling or paging messages for system information. For example, scheduling allocation information of DL-SCH for transmission of SIB (System Information Block)-1 including cell operator information, etc. can be received by examining the common search space of PDCCH (4b-01). Because system messages generally need to reach the cell edge, a common search space is defined only for aggregation levels of 4 and 8 and DCI formats such as 0/1A/3/3A/1C, the smallest of the DCI formats.

As previously explained, CRS (4b-04) is used as a reference signal for decoding of PDCCH (4b-01). CRS (4b-04) is transmitted every subframe across the entire band, and scrambling and resource mapping vary depending on the cell ID (Identity). The multi-antenna transmission technique for PDCCH (4b-01) is limited to open-loop transmission diversity.

As various technologies such as CA (Carrier Aggregation) and CoMP (Coordinated MultiPoint) are supported in conventional LTE, it has become difficult to secure sufficient transmission capacity to transmit downlink control signals using the existing PDCCH (4b-01) alone. . Accordingly, in LTE Release 11, EPDCCH (4b-02) was added as a physical channel for transmitting downlink DCI. EPDCCH (4b-02) was designed to satisfy the following requirements.

- Increased control channel transmission capacity

- Frequency axis adjacent cell interference control

- Frequency-selective scheduling

- MBSFN subframe support

- Coexistence with existing LTE terminals

As shown in FIG. 4b, the EPDCCH (4b-02) is frequency multiplexed with the PDSCH (4b-03) and transmitted. The base station can appropriately allocate resources for EPDCCH (4b-02) and PDSCH (4b-03) through scheduling, thereby effectively supporting coexistence with data transmission for existing LTE terminals. However, since the EPDCCH (4b-02) is allocated and transmitted throughout one subframe on the time axis, there is a problem that there is a loss in terms of transmission delay time. Multiple EPDCCHs (4b-02) constitute one EPDCCH (4b-02) set, and allocation of the EPDCCH (4b-02) set is made on a PRB (Physical Resource Block) pair basis. Location information for the EPDCCH set is set UE-specifically and is signaled through RRC (Remote Radio Control). Up to two EPDCCH (4b-02) sets can be configured for each terminal, and one EPDCCH (4b-02) set can be multiplexed and configured simultaneously for different terminals.

Resource allocation of EPDCCH (4b-02) is based on ECCE (Enhanced CCE). One ECCE can consist of 4 or 8 EREGs (Enhanced REG), and the number of EREGs per ECCE depends on CP length and subframe. It varies depending on the setting information. One EREG consists of 9 REs, so there can be 16 EREGs per PRB pair. EPDCCH transmission method is divided into localized/distributed transmission according to the RE mapping method of EREG. The aggregation level of ECCE can be 1, 2, 4, 8, 16, or 32, which is determined by CP length, subframe setting, EPDCCH format, and transmission method.

EPDCCH (4b-02) supports only UE-specific search space. Therefore, a terminal that wants to receive a system message must search the common search space on the existing PDCCH (4b-01). DMRS (Demodulation Reference Signal, 4b-05) is used as a reference signal for decoding EPDCCH (4b-02). EPDCCH (4b-02) supports transmission using up to 4 antenna ports. Because DMRS (4b-05) is used, the precoding for EPDCCH (4b-02) can be set by the base station, and terminals can perform decoding on EPDCCH (4b-02) without knowing what precoding was used. there is.

Above, the downlink control channel in existing LTE was explained. The downlink control channel in 5G must be designed differently from the downlink control channel in LTE. As described previously, the 5G control channel must be able to satisfy the following requirements.

- Satisfies the requirements of eMBB, URLLC, and mMTC

- Supports various TTIs simultaneously

- Supports simultaneous service of different numerology

- Ensures future compatibility

It is difficult to satisfy the above requirements with the existing control channel structure. For example, since PDCCH is transmitted in the full band, it is not suitable for mMTC, which mainly supports only narrow bands. Because EPDCCH is transmitted during one subframe, it is not suitable for URLLC, which requires very low latency. Above all, in order to support various numerologies and TTIs and ensure future compatibility, the control channel must be able to be flexibly allocated in the time and frequency domains, but the existing PDCCH and EPDCCH have difficulty in flexible allocation. Therefore, it is essential to design a new structured control channel for 5G.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. At this time, it should be noted that in the attached drawings, identical components are indicated by identical symbols whenever possible. Additionally, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted.

In addition, in describing the embodiments of the present invention in detail, the main target will be LTE and 5G systems, but the main gist of the present invention is that the scope of the present invention is largely extended to other communication systems with similar technical background and channel types. It can be applied with slight modifications without departing from the scope, and this may be possible at the discretion of a person skilled in the technical field of the present invention.

First, the 4-1 embodiment of the downlink control channel structure proposed in the present invention will be described.

[Example 4-1]

Figure 4c is a diagram showing an example of a preferred basic unit of time and frequency resources constituting the downlink control channel proposed in the present invention. According to Figure 4c, the basic unit of time and frequency resources constituting the control channel (REG (Resource Element Group), NR-REG (New Radio Resource Element Group), etc. may be named. In the present invention, for convenience, NR -REG) consists of 1 OFDM symbol (4c-01) on the time axis and 1 FU (Frequency Unit) (4c-02) on the frequency axis. At this time, 1 FU is defined as the basic unit of frequency resources that perform scheduling from the base station to the terminal. For example, if scheduling is performed based on 12 subcarriers in the frequency domain, 1 FU can be defined as a size corresponding to 12 subcarriers (i.e., 12 resource elements (RE)). The downlink control channel to be provided by the present invention has a structure that can be flexibly allocated according to the requirements of services requested by each terminal. Control channel areas of various sizes can be set by concatenating the basic units of the control channel shown in Figure 4c. For example, if the basic unit to which a control channel is allocated is called CCE, 1 CCE may consist of multiple NR-REGs. Taking the NR-REG shown in Figure 4c as an example, NR-REG can be composed of 12 REs, and if 1 CCE is composed of 3 NR-REGs, 1 CCE can be composed of 36 REs. it means. When a downlink control area is established, the area can be composed of multiple CCEs, and a specific downlink control channel can be mapped and transmitted to one or multiple CCEs depending on the aggregation level (AL) within the control area. CCEs in the control area are divided by numbers, and the numbers can be assigned according to a logical mapping method. Actual physical resource allocation for CCE can be mapped in units of NR-REG, and at this time, a block interleaver and cell-specific cyclic shift can be additionally used to strengthen the control channel. In configuring the basic unit of the control channel, the data channel and control channel can be time-multiplexed within one subframe by assuming that the basic unit of the time axis is 1 OFDM symbol. By placing the control channel before the data channel, the user's processing time can be reduced, making it easy to meet latency requirements. By setting the basic unit of the frequency axis of the control channel to 1 FU, frequency multiplexing between the control channel and the data channel can be performed more efficiently. If the basic unit of the frequency axis is composed of random subcarriers smaller than 1FU, there is a disadvantage that the frequency axis start point for scheduled data must be indicated in units of subcarriers.

Meanwhile, the basic unit of the downlink control channel shown in FIG. 4C may be composed of an area (4c-03) to which DCI is mapped and an area to which DMRS (4c-04), a reference signal for decoding the same, is mapped. At this time, DMRS (4c-04) can be transmitted efficiently considering the overhead due to RS allocation. For example, it can be turned on/off depending on the antenna port settings used by the base station or the way the downlink control channel is allocated. In other words, note that the DMRS (4c-04) may or may not be transmitted within a specific control channel basic unit, that is, NR-REG. If DMRS (4c-04) is not transmitted, the area can be used for DCI mapping.

Figure 4d is a diagram showing an example of downlink control channel setting according to the 4-1 embodiment of the present invention. Figure 4d shows an example in which downlink control channels are set differently for subframes to support services with three different TTIs. According to Figure 4d, TTI ₁ (4d-01) is composed of 14 OFDM symbols, TTI ₂ (4d-02) is composed of 7 OFDM symbols, and TTI ₃ (4d-03) is composed of 2 OFDM symbols. According to FIG. 4d, UE # ₁ with TTI 1 has a total of 3 OFDM symbols (4d-04) as a downlink control channel (CCH), and UE #2 with TTI ₂ has a total of 2. A total of one OFDM symbol (4d-06) is set for UE #3 with OFDM symbol (4d-05) and TTI ₃ , respectively. Although FIG. 4d shows an example of different settings for each terminal, note that the control channel can be set on a per-device or per-device group basis considering the complexity and efficiency of setting the control channel. In other words, note that the term terminal used in the present invention can be interpreted as a terminal group or a term with a similar meaning.

TU (Time Unit, 4d-07) indicated in 4d represents the basic time unit for scheduling. TU (4d-07) in FIG. 4D may be defined in time units such as Transmission Time Interval (TTI), subframe, slot, and mini-slot. In the example of Figure 4d, 1 TU is assumed to be 14 OFDM symbols. When the base station services terminal #1/#2/#3 with OFDMA, a subframe corresponding to 1 TTI ₁ is scheduled for terminal #1, and a subframe corresponding to 2 TTI ₂ is scheduled for terminal #2. It is scheduled, and for terminal #3, subframes corresponding to 7 TTI3 can be scheduled. In addition, according to Figure 4d, for terminal #1 and terminal #2, one control channel is set per TTI, but for terminal #3, multiple control channels are set for each TTI. In this case, control information for multiple TTIs can be bundled in the control channel allocated to terminal #3 and indicated at once on the previously received control channel.

Note that the setting of the control channel area in FIG. 4d is only an example, and the control channel area may be set differently depending on the TTI and various other system parameters.

Figure 4e is a diagram showing an example of time/frequency axis settings for a downlink control channel according to the 4-1 embodiment of the present invention. In Figure 4e, the time axis resources are expressed in OFDM symbol units and are shown as 1 TU (4e-01), and the frequency axis resources are shown as one subband (4e-03) in units of 1 FU (4e-02). Note that there is In the example of FIG. 4E, it is assumed that the subframes of UE #1 (4e-04), UE #2 (4e-05), and UE #3 (4e-06) in FIG. 4D are multiplexed in OFDMA format. As shown in Figure 4e, the control channel (CCH#1, 4e-07) of terminal #1, the control channel (CCH#2, 4e-08) of terminal #2, and the control channel (4e-09) of terminal #3 are Control channels may be set differently not only in time resources but also in frequency resources. Assignment of control channels is accomplished through the concatenation of basic units depicted in Figure 4c. As a result, the control channel area is provided in a specific pattern on the time and frequency axes. The base station can indicate information about the set control channel pattern to each terminal through RRC signaling. Alternatively, it may be indicated to each terminal through a control signal transmitted to multiple terminals, such as a common control signal or a UE group control signal. Alternatively, it can be implicitly indicated through a function using various system parameters, such as RNTI, TTI length, service type, etc.

When using the downlink control channel structure according to the 4-1 embodiment as described above, resources can be efficiently utilized for the requirements of each service by variably allocating the control channel area according to the service situation for each terminal. At this time, resource efficiency can be further improved by using resources set as a control channel for data transmission when there is no control information message to be sent. In this case, more specific base station and terminal operations are required, which will be described below considering various embodiments.

Figure 4f is a diagram showing an example of downlink transmission according to the 4-1 embodiment of the present invention.

Figure 4f shows transmission examples of terminal #1 (4f-01) and terminal #2 (4f-02) having different TTI lengths. The TTI lengths of terminal #1 (4f-01) and terminal #2 (4f-02) are set to TTI ₁ (4f-03) and TTI ₂ (4f-04), respectively. In the example of Figure 4f, PDSCH#1 (4f-05) of terminal #1 (4f-01) is allocated to some of the subbands. At this time, as shown in Figure 4f, part of the resources allocated to PDSCH#1 (4f-05) is used to use CCH#2 (4f-06), which is a control channel that exists in the second TTI of UE #2 (4f-02). For this reason, some of the preset resources may overlap. If there is no control information to be transmitted through CCH#2 (4f-06), CCH#2 (4f-06) is deactivated and PDSCH#1 (4f-05) is successfully transmitted through terminal #1 (4f-01). It can be decoded as However, if there is control information to be transmitted through CCH#2 (4f-06), interference between PDSCH#1 (4f-05) and CCH#2 (4f-06) may occur, so a base station and Terminal operation is required.

(Example 4-1-1)

As shown in Figure 4f, when the data channel (PDSCH#1(4f-05)) and the control channel (CCH#2(4f-06)) collide, the base station uses PDSCH#1(4f-05) and CCH# For resources where 2(4f-06) overlaps, CCH#2(4f-06) can be protected by puncturing part of PDSCH#1(4f-05).

Figure 4g is a diagram showing the base station and terminal procedures according to Embodiment 4-1-1 of the present invention.

First, the base station procedure of the present invention will be described. In step 4g-01, the base station configures each control channel area and transmits information about the configured control channel pattern to each terminal through RRC signaling or an implicit method. In step 4g-02, when performing scheduling for the PDSCH, the base station determines whether a preset control channel exists in the resource to which the PDSCH is to be allocated. If the control channel area does not exist, PDSCH is allocated as is (4g-05). If a control channel area exists, in step 4g-03, it is determined again whether the control channel in the area is used. If the control channel in the corresponding area is activated, a portion of the PDSCH in the corresponding area is punctured and scheduled in step 4g-04. Even if the control channel is a set resource, if the control channel in the corresponding area is not used, the PDSCH can be scheduled on the resource as is (4g-05).

Next, the terminal procedure of the present invention will be described. In step 4g-06, the terminal receives control channel area setting information from the base station. In step 4g-07, the terminal decodes its control channel to obtain scheduling information for the PDSCH. In step 4g-08, the UE may perform decoding on the PDSCH.

(Example 4-1-2)

As shown in Figure 4f, when the data channel (PDSCH#1(4f-05)) and the control channel (CCH#2(4f-06)) collide, the base station schedules PDSCH#1(4f-05). Conflict with the control channel can be avoided by performing again. In the process of performing resource allocation of PDSCH#1 (4f-05), the base station can allocate PDSCH#1 (4f-05) only to areas that avoid the control channel of other activated terminals.

Figure 4h is a diagram illustrating the base station and terminal procedures according to Embodiment 4-1-2 of the present invention.

First, the base station procedure of the present invention will be described. The base station configures the control channel area in step 4h-01 and transmits it to the terminal. In step 4h-02, the base station checks whether the resource for which the PDSCH is to be scheduled overlaps with the preset control channel area, and if not, it can schedule the PDSCH as is (4h-05). If overlapping resources exist, determine whether to use the control channel in the corresponding area (4h-03). If the control channel in the area is in use, other resources for PDSCH allocation are searched in step 4h-04, and if the control channel in the area is not in use, PDSCH allocation is performed in step 4h-05.

Next, the terminal procedure of the present invention will be described. The terminal receives configuration information for the control channel area in step 4h-06 and obtains scheduling information for its PDSCH from the downlink control information obtained by decoding its control channel in step 4h-07. In step 4h-08, the UE performs decoding on the PDSCH.

(Example 4-1-3)

As shown in Figure 4f, when the data channel (PDSCH#1(4f-05)) and the control channel (CCH#2(4f-06)) collide, the base station uses PDSCH#1(4f-05) and CCH# Considering the amount of resources overlapping with 2(4f-06), rate matching is performed on PDSCH#1(4f-05) so that CCH#2(4f-06) does not use the allocated resources. 4f-05) resources can be allocated. In this case, for successful decoding of PDSCH#1 (4f-05), additional signaling is required to indicate that some of the resources are not used due to rate matching. Each user can know information about the control channel pattern set in the current subframe from the base station's RRC signaling. In this case, the base station may transmit an indicator to the DCI of UE #1 indicating whether to use the control channel of another UE that exists in the area to which UE #1's PDSCH is allocated, for example, CCH #2 (4f-06). The terminal can know which unused resources are in the area to which its PDSCH is allocated through the preset control channel pattern and an indicator indicating whether other terminals are using the control channel received through DCI. Therefore, the terminal can perform decoding assuming that the PDSCH is allocated to the remaining portion excluding the corresponding region.

Figures 4i and 4ia are diagrams illustrating base station and terminal procedures according to Embodiment 4-1-3 of the present invention.

First, the base station procedure of the present invention will be described. The base station configures the control channel area and transmits it to the terminal (4i-01). Determine whether a control channel is set in the area where you want to schedule the PDSCH (4i-02), and determine whether the control channel is used (4i-03). If the PDSCH and the control channel of another terminal do not collide, the PDSCH is scheduled as is (4i-05). If the control channel in the corresponding area is in use, in step 4i-04, the base station excludes the corresponding area and performs PDSCH scheduling by rate matching. In step 4i-06, the base station additionally transmits an indicator about whether to use the control channel for the area where the PDSCH and the control channel overlap. In the case where there is no overlapping area between the PDSCH and the control channel, it is the same as not having an activated control channel, so the indicator for whether to use the control channel can be used as is.

Next, the terminal procedure of the present invention will be described. The terminal receives configuration information for the control channel area (4i-07) and obtains scheduling information for the PDSCH from its control channel (4i-08). In step 4i-09, the terminal determines whether its PDSCH is configured as a control channel of another terminal among the scheduled resources based on the configuration information for the control channel area. If there is no control channel for another terminal, the PDSCH is decoded as is (4i-13). If a control channel of another terminal exists, information on whether the control channel is used is obtained through step 4i-10. In step 4i-11, if the terminal receives an indicator that the control channel in the corresponding area is in use, it decodes the PDSCH excluding the corresponding area (4i-12). If an indicator is received that the control channel in the corresponding area is not in use, PDSCH decoding (4i-13) is performed as is.

Figure 4j is a diagram showing an example of downlink transmission according to the 4-1 embodiment of the present invention.

In Figure 4j, an example of PDSCH transmission of a terminal (4j-02) with a length of TTI ₁ (4j-01) is shown. As described above, if there is no control message to be transmitted through the control channel for the resource configured for the control channel, the resource can be used to transmit the PDSCH. Therefore, as shown in FIG. 4j, the start point (4j-02) of the PDSCH may vary depending on the location of the frequency resource to which the PDSCH is allocated. To explain more specifically, if the terminal (4j-02) is scheduled for PDSCH1 (4j-04), the start point of PDSCH1 (4j-04) becomes the 4th OFDM symbol. Similarly, in the case of PDSCH2 (4j-05), the 3rd OFDM symbol is used as the starting point, and in the case of PDSCH3 (4j-06), the 2nd OFDM symbol is used as the starting point. Although the control channel (4j-07) is allocated to three OFDM symbols when viewed on the time axis, the downlink control channel according to the 4-1 embodiment of the present invention supports frequency axis multiplexing with the PDSCH, so one OFDM A control channel and a data channel can exist simultaneously within a symbol. Therefore, in the example of FIG. 4J, the point where the PDSCH can start may be the 1/2/3/4th OFDM symbol point. In order for the terminal to successfully decode the PDSCH, it must know where its PDSCH starts, so additional base station and terminal operations are required for this.

(Example 4-1-4)

When the base station schedules the PDSCH, it can always allocate PDSCH resources to the OFDM symbol that follows the control channel of the corresponding terminal. In this case, the UE can assume that its PDSCH always comes after the control channel, so it can perform decoding on the PDSCH without additional signaling of the PDSCH start point.

Figure 4k is a diagram illustrating the base station and terminal procedures according to Embodiment 4-1-4 of the present invention.

First, the base station procedure of the present invention will be described. In step 4k-01, the base station sets a control channel area and transmits information about it to the terminal. In step 4k-02, when scheduling the PDSCH of a certain terminal, the base station schedules the PDSCH on the next symbol of the OFDM symbol to which the control channel is assigned, taking into account the time domain in which the control channel of the corresponding terminal is set. For example, if the control channel of the terminal is set to n OFDM symbols, the PDSCH may be allocated to the n+1th symbol.

Next, the terminal procedure of the present invention will be described. In step 4k-04, the terminal receives control channel area setting information. The terminal obtains frequency-axis scheduling information for the PDSCH from its control channel (4k-05), assumes that the starting point of the PDSCH is the OFDM symbol following its control channel, and then decodes the PDSCH (4k-06).

(Example 4-1-5)

When the base station schedules the PDSCH, an indicator for the start point of the PDSCH can be added to the DCI message providing PDSCH scheduling information and transmitted. In this case, the candidate group for the PDSCH start point is determined by the size of the control channel time domain of the user. For example, if the control channel is allocated to n OFDM symbols, the PDSCH is 1, 2, … , may start from the n+1th OFDM symbol. Ultimately, each user may have an indicator for the PDSCH start point of a different size. In this case, the DCI format can be newly defined to add message bits with different sizes for the PDSCH start point. Alternatively, the number of message bits for the PDSCH start point can be fixed and extra bits not used. At this time, the number of message bits for the PDSCH start point can be log2(nmax+1), where nmax represents the maximum number of OFDM symbols that can be assigned to the control channel. In this case, the existing DCI format can be used as is without additional DCI format.

Figure 4L is a diagram illustrating the base station and terminal procedures according to Embodiment 4-1-5 of the present invention.

First, the base station procedure of the present invention will be described. The base station sets the control channel area and transmits the relevant information to the terminal (4l-01). In step 4l-02, the base station performs scheduling for the PDSCH, and in step 4l-03, an indicator for the PDSCH start point can be added to the DCI and transmitted.

Next, the terminal procedure of the present invention will be described. The terminal receives control channel area setting information (4l-05) and obtains frequency axis scheduling information for the PDSCH from its control channel (4l-06). In step 4l-07, the UE can additionally obtain information about the start point, which is time axis scheduling information for the PDSCH, and perform decoding (4l-08) on the PDSCH based on the existing information.

Next, the 4-2 embodiment of the downlink control channel proposed in the present invention will be described.

[Example 4-2]

Before explaining the 4-2 embodiment, a more detailed description of the DCI message will be given first. As described above, there are various DCI formats depending on the data transmission method and purpose. Among these, DCI format 2C, which is one of the DCI formats that transmits downlink scheduling allocation, will be described as an example. DCI format 2C contains scheduling allocation information for PDSCH that supports closed-loop multi-antenna transmission for up to 8 layers. More specifically, DCI format 2C includes the following messages.

-Carrier indicator

- Resource allocation header

- Resource block allocation

- Power control command for PUCCH

- Downlink allocation index (index)

- HARQ process number

- RS configuration information: antenna port, scrambling sequence, number of layers

- SRS (Sounding Reference Signal) request

- MCS for transport block 1, new data indicator, redundancy version

- MCS for transport block 2, new data indicator, redundancy version

- Resource offset for HARQ-ACK (when transmitted on EPDCCH)

When transmitting downlink data, the terminal first decodes the control channel to obtain the above control information. From resource block allocation information, you can know where your PDSCH is allocated and data can be decoded based on MCS and other multi-antenna configuration information.

Figure 4m is a diagram showing the 4-2 embodiment of the present invention.

Figure 4m shows the subframe structure of terminal # ₁ (4m-02) with a TTI length of TTI 1 (4m-01) and terminal # ₂ (4m-04) with a TTI length of 2 (4m-03). According to Figure 4m, the downlink control channel according to the 4-2 embodiment of the present invention consists of a pre-control channel (Pre-CCH) and a post-control channel (Post-CCH). The subframe structure of Terminal #1 (4m-02) shows an example in which the proposed control channel is allocated for the case where the length of TTI ₁ (4m-01) is equal to 1 TU (4m-10). According to the example of Figure 4m, Pre-CCH #1 (4m-05) of UE #1 (4m-02) can be assigned to the first OFDM symbol, and Post-CCH #1 (4m-06) can be assigned to the second and third OFDM symbols. Can be assigned to an OFDM symbol. In the case of terminal #1 (4m-02), since the length of the TTI and the length of the TU are the same, one control channel can be set for 1 TU. The subframe structure of Terminal #2 (4m-04) shows an example in which the proposed control channel is allocated when the length of TTI ₂ (4m-03) is less than 1TU. In this case, Pre-CCH #2 (4m-07) of UE #2 (4m-04) is allocated to the first OFDM symbol of the first TTI, and is not allocated to the second TTI. Ultimately, in the case of Pre-CCH #2 (4m-07) of Terminal #2 (4m-04), like Terminal #1 (4m-04), it has one setting for 1 TU. On the other hand, the post-control channel of terminal #2 (4m-04) can be set one per TTI, and in the example of Figure 4m, Post-CCH ₁ #2 (4m-08) is assigned to the second OFDM symbol of the first TTI, Post-CCH ₂ #2 (4m-09) is assigned to the first and second OFDM symbols of the second TTI, respectively. Ultimately, when terminal #1 (4m-02) and terminal #2 (4m-04) are frequency multiplexed and transmitted, the pre-control channel can be transmitted through the first OFDM symbol.

Figure 4n is a diagram showing an example of time/frequency allocation for a control channel according to the 4-2 embodiment of the present invention.

Figure 4n shows an example of time and frequency allocation of the control channel for terminal #1 (4n-01) and terminal #2 (4n-02) considered in Figure 4m. According to Figure 4n, Pre-CCH #1 (4n-03), which is the pre-control channel of terminal #1 (4n-01), and Pre-CCH #2 (4n-04), which is the pre-control channel of terminal #2 (4n-02) ) may be assigned to some areas of the subband of the first OFDM symbol. The pre-control channels 4n-03 and 4n-04 shown in FIG. 4n have basically the same structure as the control channels in the 4-1 embodiment of the present invention. The pre-control channel has the same basic unit of resource allocation as described in FIG. 4C and can be set to different sizes in consideration of various system parameters corresponding to each terminal or terminal group. At this time, a preferred form of time axis resource allocation for the pre-control channel is to allow allocation to the minimum number of OFDM symbols. This has the advantage of reducing the delay time until control channel decoding by ensuring that reception of the pre-control channel is achieved in the shortest possible time, and reducing complexity by reducing the size of the area that must be investigated for blind decoding of the terminal. there is. In the example of Figure 4n, the pre-control channels (4n-03, 4n-04) of terminal #1 (4n-01) and terminal #2 (4n-02) are all assigned to one OFDM symbol. As in the 4-1 embodiment, the frequency axis allocation of the pre-control channels (4n-03, 4n-04) can be set to different sizes in certain areas of the subband according to the requirements of the terminal.

In the 4-2 embodiment of the present invention, the pre-control channel can be allocated independent resources, while the post-control channel is transmitted through PDSCH. In Figure 4n, Post-CCH #1 (4n-05) of UE #1 (4n-01) is allocated to the same frequency resource as PDSCH #1 (4n-06). Likewise, in the case of Terminal #2 (4n-02), Post-CCH ₁ #2 (4n-07) is allocated to the same frequency resource as PDSCH1 #2 (4n-08), and Post-CCH ₂ #2 (4n-08) 09) is allocated to the same frequency resource as PDSCH2#2 (4n-10). In other words, the post-control channel can be mapped and transmitted to a portion of the PDSCH, which is a data channel.

The control channel according to the 4-2 embodiment of the present invention consists of two control channels, and the mapping method of each control channel has different characteristics. In the case of the 4-2 embodiment, like the 4-1 embodiment, it is possible to variably allocate control channels to suit the service requirements of each terminal. In addition, the post-control channel resource allocation is not preset to a specific time and frequency resource like the pre-control channel, but has the characteristic that it can exist in various locations depending on whether or not the PDSCH is allocated. This has the advantage that the resources other than those allocated to the pre-control channel can be freely allocated without any restrictions on scheduling for the PDSCH. Therefore, more flexible system operation may be possible than in the 4-1 embodiment.

In the case of the pre-control channel, the control area is set and the base station signals this to the terminal so that each terminal can know the location of its own control area, while in the case of the post-control channel, the control area is mapped to a part of the resource area of the scheduled PDSCH and transmitted. Therefore, instructions for this may be necessary. Therefore, specific base station and terminal operations are required to set up the pre-control channel and post-control channel, which will be described below in consideration of various embodiments.

(Example 4-2-1)

Figure 4o is a diagram showing an example of DCI division according to Embodiment 4-2-1 of the present invention.

According to Figure 4o, the entire DCI message (4o-01) can be divided into DCI ₀ (4o-02) and DCI ₁ (4o-03). In the example of FIG. 4o, DCI0 (4o-02) includes a message about resource block allocation information (4o-04) for PDSCH, and DCI ₁ (4o-03) includes other MCS, new data indicator, redundancy version, etc. Contains messages about various downlink control information for data decoding and terminal operation. The DCI ₀ (4o-02) message can be transmitted through the pre-control channel (4o-05) and DCI ₁ (4o-03) can be transmitted through the post-control channel (4o-06).

According to embodiment 4-2-1 shown in FIG. 4o, the pre-control channel (4o-05) includes resource allocation information (4o-04) for the PDSCH. Therefore, the terminal can know the location of the PDSCH by decoding the pre-control channel, which is equivalent to knowing the location of the post-control channel (4o-06) transmitted through the PDSCH. As a result, since the terminal receives instructions for resource allocation information for the post-control channel (4o-06) from the pre-control channel (4o-05), there is no need to transmit it in a preset area unlike the pre-control channel. Therefore, more flexible control channel settings are possible.

Figure 4p is a diagram illustrating the base station and terminal procedures according to Embodiment 4-2-1 of the present invention.

First, the base station procedure of the present invention will be described. In step 4p-01, the base station performs area setting and information transmission for the pre-control channel. In step 4p-02, the base station can generate DCI ₀ and DCI ₁ messages through DCI division. In step 4p-03, the base station transmits a DCI ₀ message to the terminal through the pre-control channel. In step 4p-04, the base station transmits the DCI ₁ message to the terminal through the post-control channel mapped to the scheduled PDSCH.

Next, the terminal procedure of the present invention will be described. In step 4p-05, the terminal receives configuration information for the pre-control channel area. In step 4p-06, the terminal decodes the pre-control channel, receives the DCI ₀ message, and obtains scheduling information for the PDSCH from it. In step 4p-07, the terminal can receive the DCI ₁ message by decoding the post-control channel allocated to some areas of the scheduled PDSCH and obtain the remaining downlink control information from it. Decoding of PDSCH is performed according to downlink control information (4p-08).

(Example 4-2-2)

Figure 4q is a diagram showing an example of DCI division according to Embodiment 4-2-2 of the present invention.

Figure 4q shows an example in which a total of four DCIs (4q-01, 4q-02, 4q-03, 4q-03) are divided. The example in FIG. 4q may be an example of a situation in which a service corresponding to 4 TTIs must be transmitted during 1 TU, and the necessary control channel is transmitted a total of 4 times. According to Figure 4q, the four DCIs can be divided into one DCI ₀ (4q-09) and a total of four DCIs ₁ (4q-10, 4q-11, 4q-12, 4q-13). Both the PDSCH resource allocation information (4q-05) in the first DCI (4q-01) and the PDSCH resource allocation information (4q-06) in the second DCI (4q-02) can be divided into DCI ₀ (4q-09) messages. . Likewise, according to Figure 4q, the PDSCH resource allocation information (4q-07) in the third DCI (4q-03) and the PDSCH resource allocation information (4q-08) in the fourth DCI (4q-04) are connected to DCI1,2 (4q-11). is divided into And _, excluding the resource allocation information for a total of 4 PDSCHs, the remaining DCI information is DCI _{1,1 (} 4q-10), DCI _1,2 (4q-11), DCI _1,3 (4q-12), _{DCI 1,} It can be divided into ₄ (4q-13) messages. According to Figure 4q, DCI ₀ (4q-09) is mapped to the pre-control channel (4q-14) transmitted to the first TTI, and DCI _{1,1 (} 4q-10) is mapped to the post-control channel (4q-15) transmitted to the first TTI. ) is mapped to Likewise, DCI _{1,2 (} 4q-11), DCI _1,3 (4q-12), and DCI _1,4 ( _4q -13) are Post-CCH ₂ (4q-16), which are post-control channels corresponding to the following TTI, respectively. ), Post-CCH ₃ (4q-17), and Post-CCH ₄ (4q-18) are mapped and transmitted. The important point here is that both the pre-control channel and the post-control channel are transmitted only in the first TTI, and only the post-control channel is transmitted in subsequent TTIs. This can be considered the same case as the case of terminal #2 (4m-04, 4n-02) in FIGS. 4M and 4N already described above.

In the case of embodiment 4-2-2 shown in FIG. 4q, unlike embodiment 4-2-1 described above, the case in which multiple control channels can be transmitted in 1TU was considered. In this case, it is important to properly divide the multiple DCIs transmitted during 1TU. In Example 4-2-2, resource allocation information for PDSCH may be mapped not only to DCI ₀ but also to DCI ₁ . In service transmission corresponding to multiple TTIs, if all resource allocation information for all subsequent PDSCHs is mapped to DCI ₀ , the overhead added to DCI ₀ may be so large that it may exceed the transmission capacity provided by DCI ₀ . there is. Considering this, Figure 4q shows an example of dividing the resource allocation information of the PDSCH corresponding to the third and fourth TTI into DCI _{1 and 2} (4q-11) and transmitting them. When the terminal operates according to the example shown in Figure 4q, the terminal can know the locations of Post-CCH ₁ (4q-15) and Post-CCH ₂ (4q-16) from the pre-control channel (4q-14). And, the resource regions of Post-CCH3 (4q-17) and Post-CCH ₄ (4q-18) can be known from Post-CCH2 (4q-16). In addition, decoding of a total of 4 PDSCHs can be successfully performed through control signals.

Figure 4r is a diagram showing the base station and terminal procedures according to Embodiment 4-2-2 of the present invention. In FIG. 4r, the description will be made assuming a situation where K PDSCHs transmitted during 1 TU are transmitted.

First, the base station procedure of the present invention will be described. In step 4r-01, the base station sets an area for the pre-control channel and transmits information about it to the terminal. In step 4r-02, the base station generates one DCI ₀ and K DCI ₁ messages through DCI division. At this time, DCI ₀ has k=1,… ,This will be explained assuming a situation where resource allocation information for PDSCH _k of n is included. A DCI ₀ message may be transmitted (4r-03) through a preset pre-control channel, and DCI _1,k may be transmitted (4r-04) through a post-control channel mapped to K PDSCH _k , respectively.

Next, the terminal procedure of the present invention will be described. In step 4r-05, the terminal receives area setting information for the pre-control channel. The terminal has k=1,… from DCI ₀ of the pre-control channel. Scheduling information for PDSCH _k corresponding to n can be obtained (4r-06). In step 4r-07, the terminal receives a DCI _1,k message from the post-control channel of each PDSCH _k and obtains the remaining control information for each PDSCH _k from it. In step 4r-08, the terminal uses the control information to control PDSCH _k. Perform decoding on . Scheduling information for subsequent PDSCH k can be obtained from the last PDSCH _k for which scheduling information is known, that is, DCI _{1,m present} in PDSCH _m (4r-10). The above process is repeated until decoding for all PDSCHs is completed (4r-09).

The above-described Example 4-2-2 is merely a specific example to easily explain the technical content of the present invention and to aid understanding of the present invention, and other modifications are based on the technical idea of the present invention. Please note that this can be implemented at any time.

(Example 4-2-3)

Figure 4s is a diagram showing an example of DCI division according to Embodiment 4-2-3 of the present invention.

According to the example shown in FIG. 4S, resource allocation information (4s-02) and RS setting information (4s-03) for PDSCH can be divided among the entire DCI message (4s-01). Resource allocation information for PDSCH (4s-02) and multi-antenna setting information (4s-03) are divided into DCI ₀ (4s-04) messages, and the remaining control information is divided into DCI ₁ (4s-05) messages. It shows. DCI ₀ (4s-04) is mapped and transmitted to the pre-control channel (4s-06), and DCI ₁ (4s-05) is mapped and transmitted to the post-control channel (4s-07). According to the example shown in FIG. 4S, unlike the above-described embodiment 4-2-1 or embodiment 4-2-2, not only the resource allocation information for the PDSCH but also the RS setting information is classified into a DCI ₀ message. RS configuration information may include information such as antenna port, scrambling sequence, and number of layers, as described above.

Figure 4t is a diagram showing an example of a frame structure according to Embodiment 4-2-3 of the present invention.

Figure 4t shows the post-control channel (4t-01), the PDSCH (4t-02) through which the post-control channel is transmitted, and the DMRS (4t-03), which is a reference signal required to decode it. As shown in FIG. 4C, the downlink control channel described in the present invention can basically support decoding based on DMRS. For example, in the case of the pre-control channel, an individual RS is required for decoding the pre-control channel because it is set on an independent time/frequency resource. If the post-control channel (4t-01) is transmitted in the same way as the pre-control channel, a separate DMRS for the post-control channel (4t-01) is required. However, in the 4-2 embodiment of the present invention, the post-control channel is transmitted by being mapped to a portion of the PDSCH, so the post-control channel can be transmitted using the same transmission method as the PDSCH. In this case, the post-control channel (4t-01) can be decoded by sharing the DMRS (4t-03) of the PDSCH (4t-02) without setting an individual DMRS in the post-control channel (4t-01). In this case, there is an advantage in that RS overhead can be reduced because there is no need for an additional RS for the post-control channel. In order to use the DMRS (4t-03) of the PDSCH (4t-02) in the post-control channel (4t-01), configuration information for the DMRS (4t-03) must be received first. Therefore, as shown in Figure 4s, the RS configuration information is divided into DCI ₀ and transmitted through the pre-control channel, and the terminal can obtain DMRS configuration information for decoding the post-control channel by decoding the pre-control channel.

Figure 4u is a diagram illustrating the base station and terminal procedures according to Embodiment 4-2-3 of the present invention.

First, the base station procedure of the present invention will be described. In step 4u-01, the base station sets the area for the pre-control channel and transmits information to the terminal. In step 4u-02, DCI is divided to generate DCI ₀ and DCI ₁ messages. The base station transmits DCI ₀ through the pre-control channel (4u-03) and transmits DCI ₁ through the post-control channel of the scheduled PDSCH (4u-04).

Next, the terminal procedure of the present invention will be described. In step 4u-05, the terminal receives pre-control channel area setting information. The terminal receives the DCI ₀ message from its pre-control channel and obtains scheduling information and RS configuration information for its PDSCH from it (4u-06). In step 4u-07, the terminal can perform decoding on the post-control channel using the RS configuration information obtained from DCI1. The DCI ₁ message can be obtained from the post-control channel, through which the remaining control information for the PDSCH can be obtained (4u-08), and then decoding can be performed on the PDSCH (4u-09).

(Example 4-2-4)

A CRC (cyclic redundancy check) bit is inserted to check for errors in the DCI message containing downlink control information. To be more specific, when the size of the payload corresponding to the DCI message is A bits, a CRC parity bit equal to the size of L bits can be inserted, and the entire bit sequence (sequence) with a total length of B(=A+L) bits can be inserted. ) passes through a channel encoder to generate coded bits. When a CRC is inserted, additional scrambling is performed on the bits corresponding to the CRC. For example, it can be scrambled through modulo operation with a bit sequence corresponding to RNTI (Radio Network Temporary Identifier). After receiving the PDCCH and performing decoding, the terminal can check whether the decoded DCI message has an error through CRC determination.

According to the above-described embodiments 4-2-1, 4-2-2, and 4-2-3, the entire DCI message is divided into DCI ₀ and DCI ₁ to create a pre-control channel and a post-control channel, respectively. can be transmitted through At this time, the terminal must be able to check for errors in DCI ₀ received through the pre-control channel and DCI ₁ received through the post-control channel. Therefore, the CRC for DCI ₀ (named CRC0) and the CRC for DCI ₁ (named CRC ₁ ) must be inserted respectively. The present invention proposes the following methods for inserting a CRC.

[Method 1]

CRC ₀ can be inserted for the payload bit sequence of DCI ₀ and CRC ₁ can be inserted for the payload bit sequence of DCI ₁ . In [Method 1], errors in each DCI message transmitted separately are checked independently for DCI ₀ and DCI ₁ . To be more specific, if it is confirmed that an error has occurred through CRC ₀ , this means that the decoded DCI ₀ has an error, and if it is confirmed that an error has occurred through CRC ₁ , this means that the decoded DCI ₁ This means that there is an error. Assuming that the sizes of CRC ₀ and CRC ₁ are L ₀ bits and L ₁ bits, respectively, the values of L ₀ and L ₁ are different considering various system parameters (for example, requirements of pre-control channel and post-control channel). can be set. When performing scrambling for CRC ₀ and CRC ₁ , scrambling can be done using all or part of the RNTI depending on the values of L ₀ and L ₁ .

[Method 2]

You can insert CRC ₀ for the payload bit sequence of DCI ₀ , generate CRC ₁ for the payload bit sequence of DCI ₀ and the entire payload bit sequence of DCI ₁ , and use this as the CRC of DCI ₁ . In [Method 2], CRC ₀ can be used to check for errors in DCI ₀ , and CRC ₁ can be used to check for errors in all DCI message bits (i.e. DCI ₀ + DCI ₁ ). To be more specific, if it is confirmed that an error has occurred through CRC ₀ , this means that the decoded DCI ₀ has an error, and if it is confirmed that an error has occurred through CRC ₁ , this means that the decoded DCI ₀ Or, it means that there is an error in DCI ₁ . [Method 2] has the advantage of being more robust against false alarms for DCI ₀ because the error check for DCI ₀ is performed twice. Here, a false alarm means that an error has actually occurred, but the terminal determines that an error has not occurred. For example, if an error occurred in DCI ₀ , but the error was not detected by checking CRC ₀ , that is, if a false alarm occurred for DCI ₀ , the terminal then performs decoding on DCI ₁ and reports an error as CRC _1. It will be checked whether or not. Here, CRC ₁ detects all three cases as errors: when there is an error in DCI ₀ , when there is an error in DCI ₁ , and when there is an error in both DCI ₀ and DCI ₁ . Therefore, even if a false alarm occurs in the pre-control channel through [Method 2], the terminal can check for an error once again through decoding of the post-control channel. Assuming that the sizes of CRC ₀ and CRC ₁ are L ₀ bits and L ₁ bits, respectively, the values of L ₀ and L ₁ are different considering various system parameters (for example, requirements of pre-control channel and post-control channel). can be set. When performing scrambling for CRC ₀ and CRC ₁ , scrambling can be done using all or part of the RNTI depending on the values of L ₀ and L ₁ .

In order to perform the above embodiments of the present invention, the transmitting unit, receiving unit, and control unit of the terminal and the base station are shown in FIGS. 4V and 4W, respectively. Example 4-1, Example 4-1-1, Example 4-1-2, Example 4-1-3, Example 4-1-4, Example 4-1-5, Example 4 -2, Setting and transmitting and receiving operations for the downlink control channel corresponding to Example 4-2-1, Example 4-2-2, Example 4-2-3, and Example 4-2-4 A transmission and reception method between a base station and a terminal is shown, and in order to perform this, the transmitting unit, receiving unit, and processing unit of the base station and the terminal must each operate according to the embodiment.

Specifically, Figure 4v is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention. As shown in Figure 4v, the terminal of the present invention may include a terminal processing unit (4v-01), a receiving unit (4v-02), and a transmitting unit (4v-03).

The terminal processing unit 4v-01 can control a series of processes in which the terminal can operate according to the embodiment of the present invention described above. For example, terminal operations can be controlled differently depending on the settings of the downlink control channel according to an embodiment of the present invention.

The terminal receiver (4v-02) and the terminal transmitter (4v-03) can be collectively referred to as the transmitter/receiver in the embodiment of the present invention. The transceiver unit can transmit and receive signals to and from the base station. The signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. Additionally, the transceiver may receive a signal through a wireless channel and output it to the terminal processing unit 4v-01, and transmit the signal output from the terminal processing unit 4v-01 through a wireless channel.

Figure 4w is a block diagram showing the internal structure of a base station according to an embodiment of the present invention. As shown in FIG. 4W, the base station of the present invention may include a base station processing unit (4w-01), a receiving unit (4w-02), and a transmitting unit (4w-03).

The base station processing unit 4w-01 can control a series of processes so that the base station can operate according to the embodiment of the present invention described above. For example, the base station operation can be controlled differently depending on the settings of the downlink control channel according to the embodiment of the present invention. In addition, scheduling for the downlink control channel and data channel of the present invention can be performed and configuration information for the downlink control channel can be instructed to the terminal.

The base station receiving unit 4w-02 and the base station transmitting unit 4w-03 may be collectively referred to as the transmitting and receiving unit in the embodiment of the present invention. The transmitting and receiving unit can transmit and receive signals to and from the terminal. The signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. Additionally, the transceiver may receive a signal through a wireless channel and output it to the base station processing unit 4w-01, and transmit the signal output from the terminal processing unit 4v-01 through a wireless channel.

Meanwhile, the embodiments of the present invention disclosed in the specification and drawings are merely provided as specific examples to easily explain the technical content of the present invention and to facilitate understanding of the present invention, and are not intended to limit the scope of the present invention. In other words, it is obvious to those skilled in the art that other modifications based on the technical idea of the present invention can be implemented. Additionally, each of the above embodiments can be operated in combination with each other as needed.

Claims (20)

In a method of transmitting downlink data from a base station in a wireless communication system,
Transmitting information about a plurality of control channel resources by a transceiver to a terminal through higher layer signaling;
A step of transmitting downlink control information including resource allocation information for the downlink data and a rate matching indicator for the downlink data to the terminal by the transceiver, wherein the rate matching indicator is Indicates whether a specific control channel resource among the plurality of control channel resources is available for the downlink data; and
Comprising the step of transmitting the downlink data corresponding to the resource allocation information and the rate matching indicator by the transceiver,
When the rate matching indicator indicates that the specific control channel resource is not available for the downlink data, the downlink data is rate matched and transmitted on resources indicated by the resource allocation information excluding the specific control channel resource. A method characterized by being. The method of claim 1, wherein the information on the plurality of control channel resources includes specific pattern information in the frequency domain and time domain for each control channel resource. The method of claim 1, wherein when the rate matching indicator indicates that the specific control channel resource is available for the downlink data, the downlink data is indicated by the resource allocation information including the specific control channel resource. A method characterized in that it is transmitted from a resource. The method of claim 2, wherein the specific pattern information includes time domain information in symbol units and frequency domain information in units of 12 subcarriers. The method of claim 1, wherein resources for the downlink data are identified by excluding other control channel resources. In a method for a terminal to receive downlink data in a wireless communication system,
Receiving information about a plurality of control channel resources from a base station by a transceiver through higher layer signaling;
A step of receiving downlink control information including resource allocation information for the downlink data and a rate matching indicator for the downlink data from the base station by the transceiver, wherein the rate matching indicator is Indicates whether a specific control channel resource among the plurality of control channel resources is available for the downlink data;
Confirming, by a control unit, a resource for receiving the downlink data based on the resource allocation information and the rate matching indicator; and
Further comprising receiving the downlink data on the identified resource by the transceiver,
When the rate matching indicator indicates that the specific control channel resource is not available for the downlink data, the downlink data is rate matched and received as indicated by the resource allocation information on resources excluding the specific control channel resource. A method characterized by being. The method of claim 6, wherein the information on the plurality of control channel resources includes specific pattern information in the frequency domain and time domain for each control channel resource. The method of claim 6, wherein when the rate matching indicator indicates that the specific control channel resource is available for the downlink data, the downlink data is indicated by the resource allocation information including the specific control channel resource. A method characterized in that it is received from a resource. The method of claim 7, wherein the specific pattern information includes time domain information in symbol units and frequency domain information in units of 12 subcarriers. The method of claim 6, wherein resources for the downlink data are identified by excluding other control channel resources. In a base station transmitting downlink data in a wireless communication system,
Transmitter and receiver; and
Transmitting information about a plurality of control channel resources to the terminal through higher layer signaling;
Transmitting downlink control information including resource allocation information for the downlink data and a rate matching indicator for the downlink data to the terminal, wherein the rate matching indicator is connected to the plurality of control channels. Indicates whether a specific control channel resource among resources is available for the downlink data; and
A control unit connected to the transceiver unit that controls transmission of the downlink data corresponding to the resource allocation information and the rate matching indicator,
When the rate matching indicator indicates that the specific control channel resource is not available for the downlink data, the downlink data is rate matched and transmitted on resources indicated by the resource allocation information excluding the specific control channel resource. A base station characterized by being The base station according to claim 11, wherein the information on the plurality of control channel resources includes specific pattern information in the frequency domain and time domain for each control channel resource. The method of claim 11, wherein when the rate matching indicator indicates that the specific control channel resource is available for the downlink data, the downlink data is indicated by the resource allocation information including the specific control channel resource. A base station characterized by transmission from resources. The base station of claim 12, wherein the specific pattern information includes time domain information in symbol units and frequency domain information in units of 12 subcarriers. The base station according to claim 11, wherein resources for the downlink data are identified by excluding other control channel resources. In a terminal receiving downlink data in a wireless communication system,
Transmitter and receiver; and
Receiving information about a plurality of control channel resources from a base station through higher layer signaling;
Receiving downlink control information including resource allocation information for the downlink data and a rate matching indicator for the downlink data from the base station, wherein the rate matching indicator is connected to the plurality of control channels. Indicates whether a specific control channel resource among resources is available for the downlink data;
Confirming resources for receiving the downlink data based on the resource allocation information and the rate matching indicator; and
A control unit connected to the transceiver unit that controls reception of the downlink data on the identified resource,
When the rate matching indicator indicates that the specific control channel resource is not available for the downlink data, the downlink data is rate matched and received from resources indicated by the resource allocation information excluding the specific control channel resource. A terminal characterized by being The terminal of claim 16, wherein the information on the plurality of control channel resources includes specific pattern information in the frequency domain and time domain for each control channel resource. The method of claim 16, wherein when the rate matching indicator indicates that the specific control channel resource is available for the downlink data, the downlink data is a resource indicated by the resource allocation information including the specific control channel resource. A terminal characterized in that it is received from. The terminal of claim 17, wherein the specific pattern information includes time domain information in symbol units and frequency domain information in units of 12 subcarriers. The terminal according to claim 16, wherein resources for the downlink data are identified by excluding other control channel resources.

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