KR102288064B1 - Method and apparatus for uplink control and data transmission in wirelss cellular communication system - Google Patents

Abstract

The present disclosure relates to a communication technique that converges a 5G communication system for supporting a higher data rate after a 4G system with IoT technology, and a system thereof. The present disclosure provides intelligent services (eg, smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety related services, etc.) based on 5G communication technology and IoT-related technology. ) can be applied to The present invention relates to a wireless communication system, and to a method and apparatus for transmitting an uplink control signal or a data signal. More specifically, it relates to a transmission method in a terminal capable of uplink transmission at one or more timings for downlink data signal transmission or scheduling.

Description

Method and apparatus for uplink control and data signal transmission in a wireless cellular communication system

The present invention relates to a wireless communication system, and to a method and apparatus for transmitting an uplink control signal or a data signal. More specifically, it relates to a transmission method in a terminal capable of uplink transmission at one or more timings for downlink data signal transmission or scheduling.

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

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

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

In a wireless communication system, in particular, in a conventional LTE system, HARQ ACK or NACK information indicating whether data transmission is successful in uplink is transmitted to the base station 3 ms after receiving downlink data. For example, HARQ ACK / NACK information of a physical downlink shared channel (PDSCH) received in subframe n from the base station to the terminal is transmitted through a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) in subframe n+4 transmitted to the base station. In addition, in the FDD LTE system, the base station may transmit downlink control information (DCI) including uplink resource allocation information to the terminal or request retransmission through a physical hybrid ARQ indicator channel (PHICH). When the UE receives scheduling in subframe n, the UE performs uplink data transmission in subframe n+4. That is, PUSCH transmission is performed in subframe n+4. The above example is a description in an LTE system using FDD, and in an LTE system using TDD, HARQ ACK/NACK transmission timing or PUSCH transmission timing varies depending on the uplink-downlink subframe configuration, which is a predetermined rule performed according to

In an LTE system using FDD or TDD, HARQ ACK/NACK transmission timing or PUSCH transmission timing is a predetermined timing according to the case where the time required for signal processing between the base station and the terminal is about 3 ms. However, if the LTE base station and the terminal reduce the signal processing time to about 1 ms or 2 ms, the delay time for data transmission may be reduced.

As described above, the UE supporting transmission for reducing the delay time may be able to transmit in subframes of n+3 or n+2 as well as n+4 for scheduling or downlink data transmission in subframe n. Therefore, when uplink transmission for multiple scheduling is performed in the same subframe, it is necessary to define an uplink transmission method. Accordingly, an object of the present invention is to provide a method and apparatus for uplink transmission of a terminal when the signal processing time of the terminal can be reduced to 1 ms or 2 ms.

Another object of the present invention is to provide a method for transmitting a reference signal and a method for setting whether to transmit a reference signal or transmitting information.

Another object of the present invention is to provide a method and an apparatus for simultaneously providing different types of services. More specifically, the embodiment of the present specification provides a method for efficiently providing different types of services within the same time period by acquiring information received according to the characteristics of each service when different types of services are simultaneously provided. An object of the present invention is to provide a method and an apparatus.

The present invention for solving the above problems is a control signal processing method in a wireless communication system, the method 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 delay time can be reduced during uplink and downlink data transmission by providing a method of operating a base station and a terminal in a delay reduction mode.

In addition, according to another embodiment of the present invention, it is possible to provide an operation method capable of reducing the delay by transmitting and receiving using a short transmission time period in the transmission and reception of the terminal and the base station. That is, according to the present invention, the transmission time delay can be reduced by efficiently operating the base station and the terminal.

In addition, according to another embodiment of the present invention, data can be effectively transmitted using different types of services in a communication system. In addition, an embodiment of the present invention provides a method for coexisting data transmission between the same or heterogeneous services to satisfy the requirements according to each service, to reduce the transmission time delay, or to At least one of time and space resources and transmission power can be efficiently used.

1A is a diagram illustrating a downlink time-frequency domain transmission structure of an LTE or LTE-A system.
1B is a diagram illustrating an uplink time-frequency domain transmission structure of an LTE or LTE-A system.
FIG. 1C is a diagram illustrating a state in which data for eMBB, URLLC, and mMTC are allocated from frequency-time resources in a communication system.
FIG. 1D is a diagram illustrating a state in which data for eMBB, URLLC, and mMTC are allocated from frequency-time resources in a communication system.
1E is a diagram illustrating a structure in which one transport block is divided into several code blocks and a CRC is added according to an embodiment.
1F is a diagram illustrating operations of a base station and a terminal according to the 1-1 embodiment.
Fig. 1G is a diagram showing timing in Example 1-2.
1H is a block diagram illustrating a structure of a terminal according to embodiments.
1I is a block diagram illustrating a structure of a base station according to embodiments.
2A is a diagram illustrating a downlink time-frequency domain transmission structure of an LTE or LTE-A system according to the prior art.
2B is a diagram illustrating an uplink time-frequency domain transmission structure of an LTE or LTE-A system according to the prior art.
FIG. 2c is a diagram illustrating transmission/reception timing of a first signal and a second signal of a base station and a terminal when the transmission delay time is 0 in an LTE or LTE-A system according to the prior art.
FIG. 2D is a diagram illustrating transmission/reception timing of a first signal and a second signal of a base station and a terminal when the transmission delay time is greater than 0 and timing advance is applied in the LTE or LTE-A system according to the prior art.
FIG. 2e is a diagram illustrating transmission/reception timing of a first signal and a second signal of a base station and a terminal when the transmission delay time is greater than 0 and timing advance is applied in the LTE or LTE-A system according to the prior art.
2F is a diagram illustrating an example of using 2-symbol TTI and RS in uplink according to the 2-1 embodiment of the present invention.
2G is a diagram illustrating an example of using 2-symbol TTI and RS in uplink according to the 2-1 embodiment of the present invention.
2H is a diagram illustrating an example of using the 2-symbol TTI and RS in uplink according to the 2-1 embodiment of the present invention.
2I is a block diagram illustrating an internal structure of a terminal according to embodiments of the present invention.
2J is a block diagram illustrating an internal structure of a base station according to embodiments of the present invention.
2K is a diagram illustrating a structure of a shortened-TTI having 2 or 3 symbols included in one subframe in TTI units in uplink transmission according to an embodiment of the present invention.
3A is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which the data or control channel is transmitted in downlink in an LTE system or a similar system.
3B is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in an uplink in an LTE-A system.
FIG. 3c is a diagram illustrating a state in which data for eMBB, URLLC, and mMTC, which are services considered in a 5G or NR system, are allocated from frequency-time resources.
3D is a diagram illustrating a state in which data for eMBB, URLLC, and mMTC, which are services considered in a 5G or NR system, are orthogonally allocated in frequency-time resources.
3E is a diagram illustrating a time and frequency resource region in which a UE can perform grant-free uplink transmission.
3F is a diagram illustrating an operation of a base station according to an embodiment of the present invention.
3G is a diagram illustrating an operation of a terminal according to an embodiment of the present invention.
3H is a block diagram illustrating a structure of a terminal according to an embodiment.
3I is a block diagram illustrating the structure of a terminal according to an embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, when it is determined that a detailed description of a known function or configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the possessor of 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.

<First embodiment>

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

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

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

As described above, a plurality of services may be provided to a user in a communication system, and in order to provide such a plurality of services to a user, a method and an apparatus using the same are required to provide each service within the same time period according to characteristics. .

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

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

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

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the possessor of 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.

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

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

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

A wireless communication system, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), 3GPP2 HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE 802.16e, such as communication standards such as communication standards, such as high-speed, high-quality packet data service is developed as a broadband wireless communication system are doing In addition, a communication standard of 5G or NR (new radio) is being made as a 5G wireless communication system.

In this way, in a wireless communication system including the 5th generation, at least one service of 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 minimizes terminal power and accesses multiple terminals, and URLLC may be a service targeting high reliability and low latency, but is not limited thereto. The three services may be major scenarios in an LTE system or a system such as 5G/NR (new radio, next radio) after LTE. In the embodiment, a method for coexistence of eMBB and URLLC or a coexistence method between mMTC and URLLC and an apparatus using the same will be described.

When the base station schedules the data corresponding to the eMBB service to a certain terminal in a specific transmission time interval (TTI), if a situation occurs in which URLLC data must be transmitted in the TTI, the eMBB data is already scheduled by The generated URLLC data may be transmitted in the frequency band without transmitting a part of the eMBB data in the frequency band being transmitted. The UE scheduled for the eMBB and the UE scheduled for URLLC may be the same UE or different UEs. In this case, since a portion of the eMBB data that has already been scheduled and transmitted is not transmitted, the possibility that the eMBB data is damaged increases. Accordingly, in this case, a method for processing a signal received by a terminal scheduled for eMBB or a terminal scheduled for URLLC and a signal reception method need to be determined. Therefore, in the embodiment, when information according to eMBB and URLLC is scheduled by sharing some or all frequency bands, when information according to mMTC and URLLC are scheduled at the same time, or when information according to mMTC and eMBB is scheduled at the same time, or It describes a coexistence method between heterogeneous services that can transmit information according to each service when information according to eMBB, URLLC, and mMTC is scheduled at the same time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in the description of 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 thereof will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification. Hereinafter, the base station is a subject that performs resource allocation of the terminal, and may be at least one of an eNode B, a Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. In the present invention, downlink (DL) is a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) means a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although an embodiment of the present invention will be described below using an LTE or LTE-A system as an example, the embodiment of the present invention may be applied to other communication systems having a similar technical background or channel type. For example, 5G mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in this. In addition, the embodiments of the present invention can be applied to other communication systems through some modifications within the scope of the present invention as judged by a person having skilled technical knowledge.

As a representative example of the broadband wireless communication system, in the LTE system, an Orthogonal Frequency Division Multiplexing (OFDM) scheme is employed in a Downlink (DL), and Single Carrier Frequency Division Multiple (SC-FDMA) is used in an Uplink (UL). Access) method is adopted. Uplink refers to a radio link in which a 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 base station Refers to a radio link that transmits data or control signals to this terminal.The multiple access method as described above, in general, maintains orthogonality so that time-frequency resources for transmitting data or control information for each user do not overlap with each other. By assigning and operating so as to be established, each user's data or control information can be distinguished.

The LTE system employs a Hybrid Automatic Repeat reQuest (HARQ) method for retransmitting the corresponding data in the physical layer when a decoding failure occurs in the initial transmission. In the HARQ scheme, when the receiver fails to correctly decode (decode) data, the receiver transmits information (Negative Acknowledgment; NACK) notifying the transmitter of decoding failure so that the transmitter can retransmit the data in the physical layer. The receiver combines the data retransmitted by the transmitter with the previously unsuccessful data to improve data reception performance. In addition, when the receiver correctly decodes the data, the transmitter may transmit new data by transmitting an acknowledgment (ACK) informing the transmitter of decoding success.

1A is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which the data or control channel is transmitted in downlink in an LTE system or a similar system.

Referring to FIG. 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, and N _symb (1a02) OFDM symbols are gathered to form one slot 1a06, and two slots are gathered to configure one subframe 1a05. The length of the slot is 0.5 ms, and the length of the subframe is 1.0 ms. In addition, the radio frame 1a14 is a time domain section composed 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 N _BW (1a04) subcarriers. However, these specific numerical values may be variably applied.

A basic unit of a resource in the time-frequency domain is a resource element (1a12, Resource Element; RE) and may be represented by an OFDM symbol index and a subcarrier index. A resource block (1a08, Resource Block; RB or Physical Resource Block; PRB) may be defined as N _symb (1a02) consecutive OFDM symbols in the time domain and N _RB (1a10) consecutive subcarriers in the frequency domain. Accordingly, one RB 1a08 in one slot may include N _symb x N _RB REs 1a12. In general, the minimum allocation unit in the frequency domain of data is the RB. In the LTE system, in general, N _symb = 7, N _RB = 12, and N _BW and N _RB 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 operate by defining six transmission bandwidths. In the case of an FDD system operating by dividing downlink and uplink by frequency, the downlink transmission bandwidth and the uplink transmission bandwidth may be different from each other. The channel bandwidth represents an RF bandwidth corresponding to a system transmission bandwidth. Table 1a below shows the correspondence between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, an LTE system having a 10 MHz channel bandwidth may be configured with a transmission bandwidth of 50 RBs.

[Table 1a]

In the case of downlink control information, it may be transmitted within the first N OFDM symbols in the subframe. In an embodiment, generally N = {1, 2, 3}. Accordingly, the N value may be variably applied to each subframe according to the amount of control information to be transmitted in the current subframe. The transmitted control information may include a control channel transmission interval 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 whether it is scheduling information for uplink data (UL grant) or scheduling information for downlink data (DL grant) according to each format, whether it is a compact DCI with a small size of control information , whether spatial multiplexing using multiple antennas is applied, whether DCI for power control, etc. may be indicated. 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 allocates resources in a RBG (resource block group) unit by applying a bitmap method. The basic unit of scheduling in the LTE system is an RB expressed by time and frequency domain resources, and the RBG is composed of a plurality of RBs and becomes a basic unit of scheduling in the type 0 scheme. Type 1 allows allocating a specific RB within an RBG.

- Resource block assignment: indicates an RB allocated for data transmission. The resource to be expressed is determined according to the system bandwidth and resource allocation method.

- Modulation and coding scheme (MCS): It indicates the modulation scheme used for data transmission and the size of the transport block that is the data to be transmitted.

- HARQ process number (HARQ process number): indicates the process number of HARQ.

- New data indicator (New data indicator): indicates whether the HARQ initial transmission or retransmission.

- Redundancy version: indicates a redundancy version of HARQ.

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

The DCI is a physical downlink control channel (PDCCH) that is a downlink physical control channel (or control information, hereinafter, to be used in combination) or EPDCCH (Enhanced PDCCH) (or enhanced control information, hereinafter) through a channel coding and modulation process. It should be mixed and used).

In general, the DCI is independently scrambled with a specific RNTI (Radio Network Temporary Identifier) (or terminal identifier) for each terminal, a cyclic redundancy check (CRC) is added, and after channel coding, each is composed of an independent PDCCH. is sent 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 over the entire system transmission band.

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

Among the control information constituting the DCI, through the MCS, the base station notifies the terminal of the modulation scheme 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 a size before channel coding for error correction is applied to data (transport block, TB) to be transmitted by the base station.

The modulation schemes supported by the LTE system are Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (16QAM), and 64QAM, and each modulation order (Qm) corresponds to 2, 4, and 6. That is, in case of QPSK modulation, 2 bits per symbol, in case of 16QAM modulation, 4 bits per symbol, and in case of 64QAM modulation, 6 bits per symbol can be transmitted. In addition, a modulation scheme of 256QAM or higher may be used according to system modification.

1B is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in an uplink in an LTE-A system.

Referring to FIG. 1B , 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 SC-FDMA symbol 1b02, and N _symb ^UL SC-FDMA symbols may be gathered to form one slot 1b06. And two slots are gathered to configure one subframe (1b05). The minimum transmission unit in the frequency domain is a subcarrier, and the entire system transmission bandwidth (1b04) consists of a total of N _BW subcarriers. N _BW may have a value proportional to the system transmission band.

A basic unit of a resource in the time-frequency domain is a resource element (RE, 1b12) and may be defined as an SC-FDMA symbol index and a subcarrier index. A resource block pair (1b08, Resource Block pair; RB pair) may be defined as N _symb ^UL consecutive SC-FDMA symbols in the time domain and NscRB consecutive subcarriers in the frequency domain. Accordingly, one RB consists of N _symb ^UL x NscRB REs. In general, the minimum transmission unit of data or control information is an RB unit. In the case of PUCCH, it is mapped to a frequency domain corresponding to 1 RB and transmitted for 1 subframe.

In the LTE system, PUCCH or PUSCH which is an uplink physical channel through which HARQ ACK/NACK corresponding to PDSCH, which is a physical channel for downlink data transmission, or PDCCH/EPDDCH including semi-persistent scheduling release (SPS release) is transmitted. A timing relationship of can be defined. For example, in an LTE system operating in frequency division duplex (FDD), 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 scheme in which a data retransmission time point is not fixed. That is, when the HARQ NACK is fed back from the terminal for the initial transmission data transmitted by the base station, the base station freely determines the transmission time of the retransmission data by the scheduling operation. For the HARQ operation, the UE may perform buffering on data determined to be an error as a result of decoding the received data, and then perform combining with the next retransmission data.

HARQ ACK/NACK information of the PDSCH transmitted in subframe n is transmitted from the terminal to the base station through PUCCH or PUSCH in subframe n, where k is the FDD or TDD (time division duplex) of the LTE system and its subframe It may be defined differently depending on the setting. For example, in the case of an FDD LTE system, k is fixed to 4. Meanwhile, in the case of the TDD LTE system, k may be changed according to the subframe configuration and the subframe number. Also, when data is transmitted through a plurality of carriers, a value of k may be applied differently according to the TDD setting of each carrier. In the case of the TDD, the k value is determined according to the TDD UL/DL configuration as shown in Table 1b below.

[Table 1b]

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

When the terminal receives a PDCCH including uplink scheduling control information transmitted from the base station in subframe n or a PHICH in which downlink HARQ ACK/NACK is transmitted, uplink data corresponding to the control information in subframe n+k It is transmitted through PUSCH. In this case, k may be defined differently according to the FDD or time division duplex (TDD) 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 the TDD LTE system, k may be changed according to the subframe configuration and the subframe number. Also, when data is transmitted through a plurality of carriers, a value of k may be applied differently according to the TDD setting of each carrier. In the case of the TDD, the value of k is determined according to the TDD UL/DL configuration as shown in Table 1c below.

[Table 1c]

Meanwhile, HARQ-ACK information of PHICH transmitted in subframe i is related to PUSCH transmitted in subframe i-k. In the case of an FDD system, k is given as 4. That is, the HARQ-ACK information of the PHICH transmitted in subframe i in the FDD system is related to the PUSCH transmitted in subframe i-4. In the case of a TDD system, when only one serving cell is configured for a UE to which EIMTA is not configured, or when all of them have the same TDD UL/DL configuration, in TDD UL/DL configurations 1 to 6, according to [Table 1d] A value of k can be given.

[Table 1d]

That is, for example, in TDD UL/DL configuration 1, PHICH transmitted in subframe 6 may be HARQ-ACK information of PUSCH transmitted in subframe 2 that is 4 subframes before.

If the TDD UL/DL configuration is 0, if HARQ-ACK is received with the PHICH resource corresponding to IPHICH=0, the PUSCH indicated by the HARQ-ACK information is transmitted in subframe ik, and the k value is Table 4 is given according to When the TDD UL/DL configuration is 0, if the HARQ-ACK is received with the PHICH resource corresponding to IPHICH=1, the PUSCH indicated by the HARQ-ACK information is transmitted in subframe i-6.

The description of the wireless communication system has been described 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 another wireless communication system in an embodiment, the k value may be changed and applied to a system using a modulation scheme corresponding to FDD.

1c and 1d show how data for eMBB, URLLC, and mMTC, which are services considered in a 5G or NR system, are allocated from frequency-time resources.

Referring to FIGS. 1C and 1D , it can be seen how frequency and time resources are allocated for information transmission in each system.

First, in FIG. 1C , data for eMBB, URLLC, and mMTC are allocated in the entire system frequency band 1c00. When eMBB (1c01) and mMTC (1c09) are allocated in a specific frequency band and transmission is required because URLLC data (1c03, 1c05, 1c07) occurs during transmission, eMBB (1c01) and mMTC (1c09) are already allocated URLLC data (1c03, 1c05, 1c07) may be transmitted without emptying or transmitting. Among the above services, since it is necessary to reduce the delay time of URLLC, URLLC data may be allocated (1c03, 1c05, 1c07) to a part of the resource 1c01 to which the eMBB is allocated and transmitted. Of course, when URLLC is additionally allocated and transmitted in the resource to which the eMBB is allocated, the eMBB data may not be transmitted in the overlapping frequency-time resource, and thus the transmission performance of the eMBB data may be lowered. That is, in the above case, eMBB data transmission failure may occur due to URLLC allocation.

In FIG. 1D, the entire system frequency band 1d00 may be divided and used for service and data transmission in each subband 1d02, 1d04, and 1d06. Information related to the subband configuration may be predetermined, and this information may be transmitted from the base station to the terminal through higher level signaling. Alternatively, the information related to the subband may be arbitrarily divided by a base station or a network node to provide services to the terminal without transmission of additional subband configuration information. In FIG. 1d , subband 1d02 is used for eMBB data transmission, subband 404 is used for URLLC data transmission, and subband 1d06 is used for mMTC data transmission.

In all embodiments, a length of a transmission time interval (TTI) used for URLLC transmission may be shorter than a TTI length used for eMBB or mMTC transmission. In addition, a response of information related to URLLC can be transmitted faster than eMBB or mMTC, and thus information can be transmitted and received with low delay.

FIG. 1E is a diagram illustrating a process in which one transport block is divided into several code blocks and a CRC is added.

Referring to FIG. 1E , a CRC 1e03 may be added to the last or front part of one transport block 1e01 (TB) to be transmitted in uplink or downlink. The CRC may have 16 bits or 24 bits, a predetermined number of bits, or a variable number of bits according to channel conditions, and may be used to determine whether channel coding succeeds. Blocks 1e01 and 1e03 to which TB and CRC are added may be divided into several codeblocks (CB) 1e07, 1e09, 1e11, and 1e13 (1e05). The code block may be divided with a predetermined maximum size. In this case, the last code block 1e13 may have a smaller size than other code blocks, or 0, a random value, or 1 may be inserted so as to have the same length as other code blocks. can match CRCs 1e17, 1e19, 1e21, and 1e23 may be added to the divided code blocks, respectively (1e15). The CRC may have 16 bits or 24 bits or a predetermined number of bits, and may be used to determine whether channel coding succeeds. However, the CRC 1e03 added to the TB and the CRCs 1e17, 1e19, 1e21, and 1e23 added to the code block may be omitted depending on the type of the channel code to be applied to the code block. For example, when an LDPC code, not a turbo code, is applied to a code block, CRCs 1e17, 1e19, 1e21, and 1e23 to be inserted for each code block may be omitted. However, even when LDPC is applied, the CRCs 1e17, 1e19, 1e21, and 1e23 may be added to the code block as it is. In addition, even when a polar code is used, a CRC may be added or omitted.

The eMBB service described below is referred to as a first type service, and data for eMBB is referred to as first type data. The first type service or first type data is not limited to eMBB and may correspond to a case where high-speed data transmission is required or broadband transmission is performed. Also, URLLC service is referred to as a second type service, and data for URLLC is referred to as second type data. The second type service or the second type data is not limited to URLLC, and may correspond to other systems requiring low latency or high reliability transmission or requiring low latency and high reliability at the same time. In addition, the mMTC service is referred to as a third type service, and the data for mMTC is referred to as the third type data. The third type service or third type data is not limited to mMTC and may correspond to a case in which a low speed or wide coverage or low power is required. Also, when describing the embodiment, it may be understood that the first type service includes or does not include the third type service.

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

Although three types of services and three types of data have been described above, more types of services and corresponding data may exist, and even in this case, the contents of the present invention may be applied.

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

As described above, the embodiment defines transmission/reception operations between a terminal and a base station for first type, second type, and third type service or data transmission, and allows terminals receiving different types of service or data scheduling within the same system. Suggests specific methods for working together in In the present invention, type 1, type 2, and type 3 terminals refer to terminals that have received type 1, type 2, or type 3 service 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 different terminals.

In the following embodiment, at least one of a PHICH, an uplink scheduling grant signal, and a downlink data signal is referred to as a first signal. Also, in the present invention, at least one of an uplink data signal for uplink scheduling grant and HARQ ACK/NACK for a downlink data signal is referred to as a second signal. In the embodiment, among the signals transmitted by the base station to the terminal, if a signal is expected to receive a response from the terminal, it may be the first signal, and the response signal of the terminal corresponding to the first signal may be the second signal. Also, 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 may be a first signal, and a corresponding second signal may be PUSCH. Also, for example, in LTE and LTE-A systems, the PDSCH may be the first signal, and the PUCCH or PUSCH including HARQ ACK/NACK information of the PDSCH may be the second signal. In addition, a PDCCH/EPDCCH including an aperiodic CSI trigger may be a first signal, and a corresponding second signal may be a PUSCH including channel measurement information.

In addition, in the following embodiment, assuming that the terminal transmits the second signal at the n+k-th TTI when the base station transmits the first signal at the n-th TTI, the base station informs the terminal of the timing to transmit the second signal is the same as telling the value of k. Alternatively, if the base station transmits the second signal at the n+4+a-th TTI when the base station transmits the first signal at the n-th TTI, it is an offset that the base station informs the UE of the timing to transmit the second signal It is equivalent to giving 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, and the n+4+a value mentioned in the present invention is also the same as the offset a value in various ways. could be defined.

Although the contents of the present invention are described based on the FDD LTE system, it is applicable to the TDD system and the NR system.

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

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

In the present invention, the normal mode is a mode using the transmission timing of the first and second signals used in conventional LTE and LTE-A systems, and in the normal mode, signal processing of about 3 ms including TA It is possible to secure time. For example, in the FDD LTE system operating in the normal mode, transmission of the second signal with respect to the first signal received by the terminal in subframe n is transmitted by the terminal in subframe n+4. In the present invention, the transmission may be referred to as n+4 timing transmission. If the second signal for the first signal transmitted in subframe n+k is scheduled to be transmitted at timing n+4, it means that the second signal is transmitted in subframe n+k+4.

Meanwhile, in the present invention, the latency reduction mode is a mode that enables the transmission timing of the second signal with respect to the first signal to be faster than or equal to that of the normal mode, and the delay time can be reduced. In the delay reduction mode, the timing may be controlled in various ways. In the present invention, the reduced delay mode may be used in combination with a reduced processing time mode and the like. The setting of the delay reduction mode may be set to a terminal supporting the delay reduction mode through upper signaling. In the terminal in which the delay reduction mode is set, a second signal corresponding to the first signal transmitted in subframe n may be transmitted before subframe n+4. For example, the terminal in which the delay reduction mode is set may transmit a second signal corresponding to the first signal transmitted in subframe n in subframe n+3. In the present invention, the transmission may be referred to as n+3 timing transmission. If the second signal for the first signal transmitted in subframe n+1 is scheduled to be transmitted at timing n+3, it means that the second signal is transmitted in subframe n+4. Also, for example, if the second signal for the first signal transmitted in subframe n+2 is scheduled to be transmitted at n+3 timing, it means that the second signal is transmitted in subframe n+5. That is, if the second signal for the first signal transmitted in subframe n+k is scheduled to be transmitted at n+3 timing, it means that the second signal is transmitted in subframe n+k+3.

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

In the embodiments provided by the present invention, when the first signal is a PDSCH, the second signal may be a PUCCH or a PUSCH including HARQ-ACK information of the PDSCH. When the first signal is a PHICH or a PDCCH or an EPDCCH including uplink scheduling information, the second signal may be a PUSCH for the uplink scheduling. Also, when the first signal is a PDCCH/EPDCCH including an aperiodic CSI trigger, the second signal may be a PUSCH including channel measurement information.

In an embodiment of the present invention, the invention can be described by dividing the invention by the marks 1), 2), and 3).

[Example 1-1]

Embodiment 1-1 provides a method in which the second signal is always transmitted at a predetermined timing regardless of the setting of the delay reduction mode of the base station. This embodiment will be described with reference to FIG. 1F.

When the delay reduction mode is set to upper signaling to the terminal, the base station has uncertainty about when upper signaling is delivered to the terminal, so a method for always delivering the second signal at a predetermined timing regardless of the base station setting may be needed. there is. For example, even if the base station sets the delay reduction mode to perform n+3 timing transmission to the terminal, it cannot guarantee that the terminal knows exactly when the delay reduction mode setting is effective. Therefore, a method in which n+4 timing transmission can be performed by the base station to the terminal while the setting is made may be required. That is, a method in which n+4 timing transmission is performed may be required regardless of the delay reduction mode setting. In the present invention, a method in which n+4 timing transmission is performed regardless of the delay reduction mode setting may be used in combination with a fall-back mode transmission. Therefore, when the fallback mode transmission is performed, the base station assumes that the second signal is transmitted at n+4 timing instead of n+3 or n+2 timing and performs an uplink reception operation.

The fallback mode transmission is performed when 1) the first signal transmission is transmitted in a specific downlink control information (DCI) format, 2) when the DCI for the first signal transmission is transmitted in a specific search space, 3) At least one method may be used when DCI is transmitted using a preset specific RNTI value.

In the method 1), when the first signal transmission is transmitted in a specific DCI format as the fallback mode transmission, for example, when downlink scheduling is performed in DCI format 1A in the conventional LTE system, the delay of the base station Regardless of the mode reduction setting, the second signal may always be transmitted at n+4 timing. That is, in the above method, even if the UE is configured to transmit the second signal at the n+3 timing, if the downlink scheduling is performed in DCI format 1A, the UE transmits the second signal at the n+4 timing.

In method 2), the use of a case in which DCI for transmission of the first signal is transmitted in a specific search space as the fallback mode transmission means, for example, that DCI is transmitted in a cell common search space. When DCI is transmitted in the region set to , the second signal may always be transmitted at n+4 timing regardless of the delay mode reduction setting of the base station for the first signal related to the DCI. That is, in the above method, even if the UE is set to transmit the second signal at the n+3 timing, when the DCI is transmitted in the cell common search region, the UE transmits the second signal at the n+4 timing.

In method 3), using a case in which DCI is transmitted using a preset specific RNTI value as fallback mode transmission is, for example, setting an RNTI for fallback mode transmission to the UE in advance and using the RNTI. Therefore, when the base station generates a PDCCH or an EPDCCH and transmits DCI, the second signal can always be transmitted at n+4 timing regardless of the delay mode reduction setting of the base station for the first signal related to the DCI. That is, in the above method, even if the UE is set to transmit the second signal at the n+3 timing, if the PDCCH or EPDCCH decoding succeeds using the RNTI value, the second signal is transmitted at the n+4 timing. .

FIG. 1f is a diagram illustrating a method of uplink transmission by the terminal when the base station sets the delay reduction mode to the terminal and transmits the first signal (1f01). When the first signal from the base station is transmitted (1f01), the terminal checks whether the first signal transmission is fallback mode scheduling (1f03), and if the fallback mode transmission is correct in the check (1f03), delay reduction mode The second signal is transmitted at n+4 timing regardless of the setting (1f05). If it is not the fallback mode transmission in the check (1f03), the second signal is transmitted at a timing determined according to the delay reduction mode setting, for example, n+3 timing or n+2 timing (1f07).

[Embodiment 1-2]

In the second embodiment, when the base station sets the delay reduction mode through upper signaling to the terminal and uses the fallback mode transmission at the same time, the uplink transmission method is shown in FIG. Refer to and explain.

The terminal supporting the delay reduction mode may transmit the second signals to the first signals transmitted at various timings at the same timing. For example, the second signal for the first signal transmitted to the subframe n is transmitted to the subframe n+4, and the second signal to the first signal transmitted to the subframe n+1 is also transmitted to the subframe n+4 may be transmitted to The above example may be a case in which the fallback mode transmission is scheduled in subframe n, and a case in which the delay reduction mode is scheduled in n+3 timing transmission in subframe n+1.

1G is a diagram illustrating an example in which second signals for the first signals transmitted at various timings are scheduled to be transmitted at the same timing as described above. In FIG. 1G, in the subframe n, the fallback mode scheduling (1g10), and in the subframe n+1, the delay reduction mode scheduling (1g12) processed at the n+3 timing. That is, a case may occur in which all second signals for the first signal transmitted in subframe n and subframe n+1 are transmitted in subframe n+4 (1g14).

As described above, when the second signals for the first signals transmitted at various timings are scheduled to be transmitted at the same timing, a method for transmitting the second signal of the corresponding terminal is provided below. For ease of explanation, the second signal for the first signal transmitted to the subframe n is transmitted to the subframe n+4, and the second signal to the first signal transmitted to the subframe n+1 is also transmitted to the subframe n+ The description will be made on the assumption that it is transmitted to 4. However, the method provided in the present invention may be applied in other cases as well.

When the second signal for the first signal transmitted to the subframe n is transmitted to the subframe n+4, and the second signal to the first signal transmitted to the subframe n+1 is also transmitted to the subframe n+4 , the second signal transmitted in subframe n+4 is 1) a second signal for the first signal transmitted in subframe n, 2) a second signal for the first signal transmitted in subframe n+1, 3 ) One or more of three methods of a second signal for a first signal transmitted in subframe n and a second signal for a first signal transmitted in subframe n+1 may be used. That is, when 1g10 and 1g12 scheduling are simultaneously performed in FIG. 1G, 1) only the second signal for 1g10 scheduling, which is transmission in the fallback mode, is transmitted, 2) only the second signal is transmitted for 1g12 scheduling, which is transmission in reduced delay mode, 3) Transmission of both the second signal for 1g10 scheduling, which is the fallback mode transmission, and the second signal for 1g12 scheduling, which is the delay reduction mode transmission, may be used.

In method 1), the terminal transmits only the second signal corresponding to the first signal transmitted in subframe n in subframe n+4. That is, the UE transmits the second signal for the first signal transmitted in subframe n in subframe n+4 regardless of whether scheduling is performed in subframe n+1. The first signal transmitted in the subframe n is scheduled to transmit the second signal at n+4 timing, and may be, for example, fallback mode transmission. The first signal transmitted in the subframe n+1 is scheduled to transmit the second signal at the n+3 timing, and thus the second signal must be transmitted at n+4, which is, for example, a delay reduction mode setting transmission date can For example, PDSCH is transmitted in subframe n, the PDSCH is scheduled so that the UE transmits HARQ-ACK at n+4 timing, and HARQ-ACK is transmitted at n+3 timing in subframe n+1. If the scheduled PDSCH or the PDCCH/EPDCCH scheduled to transmit the PUSCH at the n+3 timing is transmitted, the UE ignores the scheduled first signal so that the second signal is transmitted at the n+3 timing transmitted in the subframe n+1. and HARQ-ACK for the PDSCH transmitted in subframe n may be transmitted in subframe n+4. As another example, a PDCCH/EPDCCH including PUSCH scheduling information was transmitted in subframe n. The scheduling is such that the UE transmits the PUSCH at n+4 timing, and in subframe n+1, at n+3 timing. When a PDSCH scheduled to transmit HARQ-ACK or a PDCCH/EPDCCH scheduled to transmit PUSCH at n+3 timing is transmitted, the UE schedules so that the second signal is transmitted at n+3 timing transmitted in subframe n+1 The first signal may be ignored, and the PUSCH scheduled in subframe n may be transmitted in subframe n+4.

In method 2), the terminal transmits only the second signal corresponding to the first signal transmitted in subframe n+1 in subframe n+4. That is, the UE transmits the second signal for the first signal transmitted in subframe n+1 in subframe n+4 regardless of whether scheduling is performed in subframe n. The first signal transmitted in the subframe n is scheduled to transmit the second signal at n+4 timing, and may be, for example, fallback mode transmission. The first signal transmitted in the subframe n+1 is scheduled to transmit the second signal at the n+3 timing, and thus the second signal must be transmitted at n+4, which is, for example, the delay reduction mode setting transmission date can For example, PDSCH is transmitted in subframe n+1, the PDSCH is scheduled so that the UE transmits HARQ-ACK at n+3 timing, and HARQ-ACK is transmitted at n+4 timing in subframe n. When the scheduled PDSCH or the PDCCH / EPDCCH scheduled to transmit the PUSCH at the n+4 timing is transmitted, the UE ignores the first signal scheduled to transmit the second signal at the n+4 timing transmitted in subframe n, HARQ-ACK for the PDSCH transmitted in subframe n+1 may be transmitted in subframe n+4. As another example, the PDCCH/EPDCCH including PUSCH scheduling information was transmitted in subframe n+1. The scheduling is such that the UE transmits the PUSCH at n+3 timing, and in subframe n, at n+4 timing. When a PDSCH scheduled to transmit HARQ-ACK or a PDCCH/EPDCCH scheduled to transmit PUSCH at n+4 timing is transmitted, the UE transmits a second signal scheduled to be transmitted at n+4 timing transmitted in subframe n. Signal 1 may be ignored and the PUSCH scheduled in subframe n+1 may be transmitted in subframe n+4.

In method 3), the terminal simultaneously transmits a second signal for the first signal transmitted in subframe n and a second signal for the first signal transmitted in subframe n+1 in subframe n+4. . The first signal transmitted in the subframe n is scheduled to transmit the second signal at n+4 timing, and may be, for example, fallback mode transmission. The first signal transmitted in the subframe n+1 is scheduled to transmit the second signal at the n+3 timing, and thus the second signal must be transmitted at n+4, which is, for example, a delay reduction mode setting transmission date can For example, PDSCH is transmitted in subframe n, the PDSCH is scheduled so that the UE transmits HARQ-ACK at n+4 timing, and HARQ-ACK is transmitted at n+3 timing in subframe n+1. When the scheduled PDSCH is transmitted, the UE may simultaneously transmit HARQ-ACK information for the PDSCH transmitted in subframe n and HARQ-ACK information for the PDSCH transmitted in subframe n+1 in subframe n+4. As a method of simultaneously transmitting HARQ-ACK information of the two PDSCHs in subframe n+4, PUCCH or PUSCH may be used, and the two HARQ-ACK information may be multiplexed or bundled. For example, in the bundling method, the UE transmits ACK information to the base station in subframe n+4 only when both the PDSCH transmitted in subframe n and the PDSCH transmitted in subframe n+1 are successfully decoded. That is, when at least one of the PDSCH transmitted in subframe n and the PDSCH transmitted in subframe n+1 fails to decode, the UE transmits NACK information to the base station in subframe n+4. In the above, the selection of multiplexing or bundling may be a higher level signal from the base station to the terminal.

In addition, in method 3), for example, PDSCH transmission was performed in subframe n, the PDSCH was scheduled for the UE to transmit HARQ-ACK at n+4 timing, and in subframe n+1, n+3 When the PDCCH/EPDCCH scheduled to transmit the PUSCH at the timing is transmitted, the UE includes HARQ-ACK information for the PDSCH transmitted in subframe n in the PUSCH scheduled in subframe n+1 and simultaneously in subframe n+4. can be transmitted In addition, for example, an aperiodic CSI trigger is delivered to the UE at n+4 timing in subframe n. Channel state information (CSI) for an aperiodic CSI trigger transmitted in subframe n may be included in the PUSCH scheduled in subframe n+1 and transmitted simultaneously in subframe n+4.

In addition, in method 3), as another example, a PDCCH/EPDCCH including PUSCH scheduling information was transmitted in subframe n. The scheduling is such that the UE transmits the PUSCH at timing n+4, and subframe n+1 In , when a PDSCH scheduled to transmit HARQ-ACK is transmitted at timing n+3, the UE includes HARQ-ACK information for the PDSCH transmitted in subframe n+1 in the PUSCH scheduled for subframe n to include a subframe It can transmit simultaneously on n+4. In addition, as another example, a PDCCH/EPDCCH including PUSCH scheduling information was transmitted in subframe n. In the scheduling, the UE transmits the PUSCH at timing n+4, and PUSCH at timing n+3 in subframe n+1. When the PDCCH/EPDCCH scheduled to be transmitted is transmitted, if the two PUSCH transmission resources are not the same, two PUSCHs may be transmitted simultaneously.

Methods 1), 2), and 3) described above may be used interchangeably according to scheduling in subframe n and subframe n+1. For example, PDSCH is transmitted in subframe n, the PDSCH is scheduled so that the UE transmits HARQ-ACK at n+4 timing, and HARQ-ACK is transmitted at n+3 timing in subframe n+1. When the scheduled PDSCH is transmitted, the UE may simultaneously transmit HARQ-ACK information for the PDSCH transmitted in subframe n and HARQ-ACK information for the PDSCH transmitted in subframe n+1 in subframe n+4. As a method of simultaneously transmitting HARQ-ACK information of the two PDSCHs in subframe n+4, PUCCH or PUSCH may be used, and the two HARQ-ACK information may be multiplexed or bundled. On the other hand, the PDCCH/EPDCCH including PUSCH scheduling information is transmitted in subframe n+1. The scheduling is such that the UE transmits the PUSCH at n+3 timing, and in subframe n, the PUSCH is transmitted at n+4 timing. When the scheduled PDCCH / EPDCCH is transmitted, the UE ignores the scheduling for transmitting the PUSCH at the n+4 timing transmitted in the subframe n, and transmits only the PUSCH scheduled in the subframe n+1 to the subframe n+4. there is.

In order to carry out the above embodiments of the present invention, a transmitter, a receiver, and a processor of the terminal and the base station are shown in FIGS. 1H and 1I, respectively. In order to determine the transmission/reception timing and terminal transmission power of the second signal from the methods 1) to 3) of the 1-1 embodiment to the methods 1) to 3) of the 1-2 embodiment, the base station and the terminal perform an operation according thereto. is shown, and in order to perform this, the receiving unit, the processing unit, and the transmitting unit of the base station and the terminal must operate according to the embodiment, respectively.

Specifically, FIG. 1H is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present invention. As shown in FIG. 1H, the terminal of the present invention may include a terminal receiving unit 1h00, a terminal transmitting unit 1h04, and a terminal processing unit 1h02. In an embodiment of the present invention, the terminal receiving unit 1h00 and the terminal collectively refer to the transmitting unit 1h04, and may be referred to as a transceiver. The transceiver may transmit/receive a signal to/from the base station. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel, output it to the terminal processing unit 1h02, and transmit a signal output from the terminal processing unit 1h02 through a wireless channel. The terminal processing unit 1h02 may control a series of processes so that the terminal can operate according to the above-described embodiment of the present invention. For example, the terminal receiving unit 1h00 may receive a signal including the second signal transmission timing information from the base station, and the terminal processing unit 1h02 may control to interpret the second signal transmission timing. Thereafter, the terminal transmitter 1h04 transmits the second signal at the above timing.

1I is a block diagram illustrating an internal structure of a base station according to an embodiment of the present invention. As shown in FIG. 1I, the base station of the present invention may include a base station receiving unit 1i01, a base station transmitting unit 1i05, and a base station processing unit 1i03. In an embodiment of the present invention, the base station receiving unit 1i01 and the base station transmitting unit 1i05 may be collectively referred to as a transceiver. The transceiver may transmit/receive a signal to/from the terminal. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel and output it to the base station processing unit 1i03, and transmit the signal output from the terminal processing unit 1i03 through the wireless channel. The base station processing unit 1i03 may control a series of processes so that the base station can operate according to the above-described embodiment of the present invention.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are merely presented as specific examples to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. That is, it will be apparent to those of ordinary skill in the art to which the present invention pertains that other modified examples can be implemented based on the technical spirit of the present invention. In addition, each of the above embodiments may be operated in combination with each other as needed. For example, the base station and the terminal may be operated by combining parts of embodiments 1-1 and 1-2 of the present invention. In addition, although the above embodiments have been presented based on the LTE/LTE-A system, other modifications based on the technical idea of the embodiment may be implemented in other systems such as 5G and NR systems.

<Second embodiment>

A wireless communication system, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), 3GPP2 HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE 802.16e, such as communication standards such as communication standards, such as high-speed, high-quality packet data service is developed as a broadband wireless communication system are doing In addition, a communication standard of 5G or NR (new radio) is being made as a 5G wireless communication system.

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

The LTE system employs a Hybrid Automatic Repeat reQuest (HARQ) method for retransmitting the corresponding data in the physical layer when a decoding failure occurs in the initial transmission. In the HARQ scheme, when the receiver fails to correctly decode (decode) data, the receiver transmits information (Negative Acknowledgment; NACK) notifying the transmitter of decoding failure so that the transmitter can retransmit the data in the physical layer. The receiver combines the data retransmitted by the transmitter with the previously unsuccessful data to improve data reception performance. In addition, when the receiver correctly decodes the data, the transmitter may transmit new data by transmitting an acknowledgment (ACK) informing the transmitter of decoding success.

One of the important criteria for cellular wireless communication system performance is packet data latency. To this end, in the LTE system, signal transmission and reception is performed in units of subframes having a transmission time interval (TTI) of 1 ms. In the LTE system operating as described above, it is possible to support a terminal (shortened-TTI/shorter-TTI UE) having a transmission time period shorter than 1 ms. The Shortened-TTI terminal is expected to be suitable for services such as Voice over LTE (VoLTE) service and remote control where latency is important. In addition, the shortened-TTI terminal is expected as a means capable of realizing the cellular-based, mission-critical Internet of Things (IoT).

In the current LTE and LTE-A systems, the base station and the terminal are designed so that transmission and reception are performed in units of subframes with a transmission time period of 1 ms. In order to support a shortened-TTI terminal operating in a transmission time period shorter than 1 ms in an environment in which a base station and a terminal operating with a transmission time interval of 1 ms exist, a transmission/reception operation differentiated from general LTE and LTE-A terminals is defined. Needs to be. Therefore, the present invention proposes a specific method for operating a general LTE and LTE-A terminal and a shortened-TTI terminal together in the same system.

In the conventional LTE system, a common cell RS or an RS for demodulation is transmitted in every subframe. However, since the ratio of RS in short TTI transmission may be greater than in long TTI transmission, it may be advantageous to omit RS transmission instead of transmitting RS in every TTI in short TTI transmission. The present invention relates to a transmission/reception method and apparatus having a transmission time interval shorter than 1 ms in the conventional LTE system, but is applicable not only to the LTE system but also to the 5G/NR system.

2A is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which the data or control channel is transmitted in downlink in an LTE system.

In FIG. 2A , 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, where N _symb (2a02) OFDM symbols are gathered to form one slot 2a06, and two slots to form one subframe 2a05. The length of the slot is 0.5 ms, and the length of the subframe is 1.0 ms. And the radio frame 2a14 is a time domain section composed 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 N _BW (2a04) subcarriers.

A basic unit of a resource in the time-frequency domain is a resource element (2a12, Resource Element; RE) and may be represented by an OFDM symbol index and a subcarrier index. A resource block (2a08, Resource Block; RB or Physical Resource Block; PRB) is defined as N _symb (2a02) consecutive OFDM symbols in the time domain and N _RB (2a10) consecutive subcarriers in the frequency domain. Accordingly, one RB 108 is composed of N _symb x N _RB REs 2a12 . In general, the minimum transmission unit of data is the RB unit. In the LTE system, in general, N _symb = 7, N _RB = 12, and N _BW and N _RB are 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 defines and operates six transmission bandwidths. In the case of an FDD system operating by dividing downlink and uplink by frequency, the downlink transmission bandwidth and the uplink transmission bandwidth may be different from each other. The channel bandwidth represents an RF bandwidth corresponding to a system transmission bandwidth. Table 2a shows the correspondence between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, an LTE system having a 10 MHz channel bandwidth has a transmission bandwidth of 50 RBs.

[Table 2a]

Downlink control information is transmitted within the first N OFDM symbols in the subframe. In general, N = {1, 2, 3}. Accordingly, the value of N varies for each subframe according to the amount of control information to be transmitted in the current subframe. The control information includes a control channel transmission interval indicator indicating how many OFDM symbols the control information is transmitted over, scheduling information for downlink data or uplink data, HARQ ACK/NACK signals, and the like.

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 defines various formats, whether it is scheduling information for uplink data (UL grant) or scheduling information for downlink data (DL grant), whether it is a compact DCI with a small size of control information, using multiple antennas It operates by applying a DCI format determined according to whether spatial multiplexing is applied or whether it is DCI 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 (Resource allocation type 0/1 flag): Notifies whether the resource allocation method is type 0 or type 1. Type 0 allocates resources in a RBG (resource block group) unit by applying a bitmap method. The basic unit of scheduling in the LTE system is an RB expressed by time and frequency domain resources, and the RBG is composed of a plurality of RBs and becomes a basic unit of scheduling in the type 0 scheme. Type 1 allows allocating a specific RB within an RBG.

- Resource block assignment: Notifies the RB allocated for data transmission. The resource to be expressed is determined according to the system bandwidth and resource allocation method.

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

- HARQ process number (HARQ process number): Notifies the process number of HARQ.

- New data indicator (New data indicator): Notifies whether 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 a transmit power control command for PUCCH, which is an uplink control channel.

The DCI is a downlink physical control channel (PDCCH) (Physical downlink control channel) (or control information, hereinafter to be used in combination) or EPDCCH (Enhanced PDCCH) (or enhanced control information, hereinafter) through a channel coding and modulation process It is transmitted through the mixed use).

In general, the DCI is independently scrambled with a specific RNTI (Radio Network Temporary Identifier) (or terminal identifier) for each terminal, a cyclic redundancy check (CRC) is added and channel-coded, and is configured as an independent PDCCH for transmission. do. 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 a Physical Downlink Shared Channel (PDSCH), which is a physical channel for downlink data transmission. The PDSCH is transmitted after the control channel transmission period, and the DCI transmitted through the PDCCH informs scheduling information such as a specific mapping position and a modulation method in the frequency domain.

Among the control information constituting the DCI, the base station notifies the UE of the modulation scheme applied to the PDSCH to be transmitted and the size of the data to be transmitted (transport block size; TBS) through the MCS composed of 5 bits. The TBS corresponds to a size before channel coding for error correction is applied to data (transport block, TB) to be transmitted by the base station.

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

2B is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in an uplink in an LTE-A system according to the prior art.

Referring to FIG. 2B , 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 SC-FDMA symbol 2b02, and N _symb ^UL SC-FDMA symbols are gathered to form one slot 2b06. And two slots are gathered to configure one subframe (2b05). The minimum transmission unit in the frequency domain is a subcarrier, and the entire system transmission bandwidth (2b04) consists of a total of N _BW subcarriers. N _BW has a value proportional to the system transmission band.

A basic unit of a resource in the time-frequency domain is a resource element (RE, 2b12) and may be defined as an SC-FDMA symbol index and a subcarrier index. A resource block pair (2b08, Resource Block pair; RB pair) is defined as N _symb ^UL consecutive SC-FDMA symbols in the time domain and NscRB consecutive subcarriers in the frequency domain. Accordingly, one RB consists of N _symb ^UL x NscRB REs. In general, the minimum transmission unit of data or control information is an RB unit. In the case of PUCCH, it is mapped to a frequency domain corresponding to 1 RB and transmitted for 1 subframe.

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

In the LTE system, downlink HARQ adopts an asynchronous HARQ scheme in which a data retransmission time point is not fixed. That is, when the HARQ NACK is fed back from the terminal for the initial transmission data transmitted by the base station, the base station freely determines the transmission time of the retransmission data by the scheduling operation. For HARQ operation, the UE performs buffering on data determined to be an error as a result of decoding received data, and then combines with the next retransmission data.

Upon receiving the PDSCH including downlink data transmitted from the base station in subframe n, the terminal transmits 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 In this case, k is defined differently according to the FDD or time division duplex (TDD) of the LTE system and its subframe settings. For example, in the case of an FDD LTE system, k is fixed to 4. Meanwhile, in the case of the TDD LTE system, k may be changed according to the subframe configuration and the subframe number.

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

When the terminal receives a PDCCH including uplink scheduling control information transmitted from the base station in subframe n or a PHICH in which downlink HARQ ACK/NACK is transmitted, uplink data corresponding to the control information in subframe n+k It is transmitted through PUSCH. In this case, k is defined differently according to 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 is fixed to 4. Meanwhile, in the case of the TDD LTE system, k may be changed according to the subframe configuration and the subframe number.

And when the UE receives a PHICH carrying downlink HARQ ACK/NACK from the base station in subframe i, the PHICH corresponds to the PUSCH transmitted by the UE in subframe i-k. In this case, k is defined differently depending on the FDD or TDD of the LTE system and its configuration. For example, in the case of an FDD LTE system, k is fixed to 4. Meanwhile, in the case of the TDD LTE system, k may be changed according to the subframe configuration and the subframe number.

FIG. 2C is a diagram illustrating timings of a base station and a terminal when receiving uplink scheduling approval and transmitting uplink data or receiving downlink data and transmitting HARQ ACK or NACK in an FDD LTE system. When the base station transmits an uplink scheduling grant or a downlink control signal and data to the terminal in subframe n (2c01), the terminal receives the uplink scheduling grant or a downlink control signal and data in subframe n (2c03). . First, when receiving uplink scheduling approval in subframe n, the UE transmits uplink data in subframe n+4 (2c07). If the downlink control signal and data are received in subframe n, the UE transmits HARQ ACK or NACK for downlink data in subframe n+4 (2c07). Accordingly, the UE receives uplink scheduling approval, transmits uplink data, receives downlink data, and prepares to transmit HARQ ACK or NACK is 3 ms corresponding to 3 subframes (2c09).

On the other hand, since the terminal is generally far from the base station, the signal transmitted from the terminal is received by the base station after a propagation delay time. The propagation delay time can be regarded as a value obtained by dividing the path through which radio waves are transmitted from the terminal to the base station by the speed of light, and in general, it can also be considered as a value obtained by dividing the distance from the terminal to the base station by the speed of light. For example, in the case of a terminal located 100 km away from the base station, a signal transmitted from the terminal is received by the base station after about 0.34 msec. Conversely, the signal transmitted from the base station is also received by the terminal after about 0.34 msec. As described above, the arrival time of a signal transmitted from the terminal to the base station may vary according to the distance between the terminal and the base station. Therefore, when multiple terminals located in different locations transmit signals at the same time, arrival times at the base station may all be different. In order to solve this phenomenon and make the signals transmitted from multiple terminals arrive at the base station at the same time, the transmission time should be slightly different for each terminal according to the location, which is called timing advance in the LTE system.

In the LTE system, the terminal transmits a RACH signal or a preamble to the base station to perform random access (RA), and the base station calculates a timing advance value required for uplink synchronization of the terminals, and the result is A timing advance value of 11 bits is delivered to the UE through a random access response. The UE performs uplink synchronization using the received timing advance value. Thereafter, the base station continuously measures a timing advance value additionally necessary for the terminal for uplink synchronization and delivers it to the terminal. The additional timing advance value is transmitted as 6 bits through a MAC control element. The terminal adjusts the timing advance value by adding the received additional timing advance value of 6 bits to the already applied timing advance value.

2d is a timing relationship according to timing advance according to the distance between the terminal and the base station when the terminal receives uplink scheduling approval and transmits uplink data or receives downlink data and transmits HARQ ACK or NACK in the FDD LTE system. is a diagram showing When the base station transmits an uplink scheduling grant or a downlink control signal and data to the terminal in subframe n (2d02), the terminal receives the uplink scheduling grant or a downlink control signal and data in subframe n (2d04). . At this time, the terminal receives the transmission delay time TP (2d10) later than the time transmitted by the base station. First, when receiving uplink scheduling approval in subframe n, the UE transmits uplink data in subframe n+4 (2d06). If the downlink control signal and data are received in subframe n, the UE transmits HARQ ACK or NACK for downlink data in subframe n+4 (2d06). Even when the terminal transmits a signal to the base station, in order to arrive at the base station at a certain time, the uplink data or downlink at a timing (2d06) that is advanced by TA (2d12) from subframe n+4 of the signal reference received by the terminal Transmits HARQ ACK/NACK for data. Therefore, the UE receives uplink scheduling approval, transmits uplink data, or receives downlink data and prepares to transmit HARQ ACK or NACK is 3 ms corresponding to 3 subframes, excluding TA. becomes (2d14). The 3 ms - TA is a standard of the conventional LTE system in which the TTI is 1 ms, and when the TTI length is shortened and the transmission timing is changed, 3 ms - TA may be changed to another value.

The base station calculates the absolute value of the TA of the corresponding terminal. The base station can calculate the absolute value of the TA by adding or subtracting the amount of change in the TA value transmitted through higher signaling thereafter to the TA value first delivered to the terminal in the random access step when the terminal initially accesses it. In the present invention, the absolute value of the TA may be a value obtained by subtracting the start time of the nth TTI received by the UE from the start time of the nth TTI transmitted by the UE.

Meanwhile, one of the important criteria for performance of a cellular wireless communication system is packet data latency. To this end, in the LTE system, signal transmission and reception is performed in units of subframes having a transmission time interval (TTI) of 1 ms. In the LTE system operating as described above, a terminal (short-TTI UE) having a transmission time period shorter than 1 ms may be supported. Meanwhile, in NR, which is a 5G mobile communication system, the transmission time interval may be shorter than 1 ms. The Short-TTI terminal is expected to be suitable for services such as Voice over LTE (VoLTE) service and remote control where latency is important. In addition, the short-TTI terminal is expected as a means capable of realizing the cellular-based, mission-critical Internet of Things (IoT).

3 ms, which is a time during which the UE can prepare a transmission signal, shown in FIG. 2D - TA may be changed as shown in FIG. 2E in the case of a short-TTI UE or in the case of a UE having a large absolute value (2e11) of TA. For example, when the uplink scheduling grant is transmitted in the n-th TTI (501, 503) and the corresponding uplink data is transmitted in the n+4th TTI (2e05, 2e07), 3 TTIs - TA (2e13) will be the preparation time of the terminal. If the TTI length is shorter than 1 ms and the TA is large because the distance between the terminal and the base station is large, the value of 3 TTIs - TA, which is the preparation time of the terminal, may be small or even negative. In order to solve this problem, the maximum value of the TA assumed by the UE for the short-TTI operation may be separately set. The maximum value of the TA for the short-TTI operation is smaller than the maximum value of the TA of the conventional LTE system, and is not predetermined between the base station and the terminal, and may be a value arbitrarily assumed to determine the terminal support capability. Therefore, a terminal supporting the short-TTI operation needs a method of operation when a TA exceeding the maximum TA for the short-TTI operation is allocated. Alternatively, there is a need for a method in which the terminal transmits information on whether a short-TTI operation is possible to the base station.

Alternatively, in the NR system, the types of supported services may be divided into categories such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low-latency communications (URLLC). eMBB is a high-speed transmission of high-capacity data, mMTC is a service that minimizes terminal power and connects multiple terminals, and URLLC is a service that aims for high reliability and low latency. Different requirements may be applied according to the type of service applied to the terminal. For example, it may be important to perform a given operation within a predetermined processing time for each service type. Since low latency is important for URLLC, it may be important to perform a predetermined operation within a short time. Accordingly, the limit of the TA value required for the terminal may vary according to the type of service provided to the terminal. It may be specified that the UE assumes different maximum TA values for each service, or the UE may assume the same maximum TA value even if the services are different.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, when it is determined that a detailed description of a function or configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification. Hereinafter, the base station is a subject that performs resource allocation of the terminal, and may be at least one of an eNode B, a Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. In the present invention, a downlink (DL) is a wireless transmission path of a signal transmitted from a base station to a terminal, and an uplink (UL) is a wireless transmission path of a signal transmitted from a terminal to a flag station. In addition, although an embodiment of the present invention will be described below using an LTE or LTE-A system as an example, the embodiment of the present invention may be applied to other communication systems having a similar technical background or channel type. For example, 5G mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in this. In addition, the embodiments of the present invention may be applied to other communication systems through some modifications within the scope of the present invention as judged by a person having skilled technical knowledge.

Unless otherwise specified below, the described shortened-TTI terminal may be referred to as a first type terminal, and the normal-TTI terminal may be referred to as a second type terminal. The first type terminal may include a terminal capable of transmitting control information, or data, or control information and data in a transmission time interval of 1 ms or shorter than 1 ms, and the second type terminal is controlled in a transmission time interval of 1 ms It may include a terminal capable of transmitting information or data, or control information and data. Meanwhile, hereinafter, a shortened-TTI terminal and a type 1 terminal are mixed and used, and a normal-TTI terminal and a type 2 terminal are mixed and used. Also, in the present invention, shortened-TTI, shorter-TTI, shortened TTI, shorter TTI, short TTI, and sTTI have the same meaning and are used interchangeably. Also, in the present invention, normal-TTI, normal TTI, subframe TTI, and legacy TTI have the same meaning and are used interchangeably.

The shortened-TTI transmission described below may be referred to as a first type transmission, and the normal-TTI transmission may be referred to as a second type transmission. The first type transmission is a method in which a control signal, or a data signal, or a control and data signal is transmitted in a section shorter than 1 ms, and in the second type transmission, a control signal, or a data signal, or a control and data signal is transmitted in a section shorter than 1 ms the way it is transmitted. Meanwhile, hereinafter, shortened-TTI transmission and type 1 transmission are mixed and used, and normal-TTI transmission and type 2 transmission are mixed and used. The first type terminal may support both type 1 transmission and type 2 transmission, or may support only type 1 transmission. The second type terminal supports the second type transmission, but does not support the first type transmission. In the present invention, for convenience, the term "for a first type terminal" may be interpreted as for the first type transmission. If normal-TTI and longer-TTI exist instead of shortened-TTI and normal-TTI, normal-TTI transmission may be referred to as a first type transmission, and longer-TTI transmission may be referred to as a second type transmission. In the present invention, the first type reception and the second type reception may refer to a process of receiving first type transmission and second type transmission signals, respectively.

In the present invention, the transmission time interval in the downlink means a unit in which a control signal and a data signal are transmitted, or may mean a unit in which a data signal is transmitted. For example, in the downlink of the existing LTE system, a transmission time interval is a subframe that is a time unit of 1 ms. Meanwhile, in the present invention, the transmission time interval in the uplink means a unit in which a control signal or a data signal is transmitted, or may mean a unit in which a data signal is transmitted. The transmission time period in the uplink of the existing LTE system is a subframe that is the same time unit as the downlink of 1 ms.

In addition, in the present invention, the shortened-TTI mode is a case in which a terminal or a base station transmits and receives a control signal or a data signal in units of shortened TTI, and in the normal-TTI mode, a terminal or a base station transmits and receives a control signal or a data signal in units of subframes. is the case

In addition, in the present invention, shortened-TTI data means data transmitted in PDSCH or PUSCH transmitted and received in units of shortened TTI, and normal-TTI data means data transmitted in PDSCH or PUSCH transmitted and received in units of subframes. In the present invention, the control signal for shortened-TTI means a control signal for shortened-TTI mode operation and is referred to as sPDCCH, and the control signal for normal-TTI means a control signal for normal-TTI mode operation. For example, the control signal for normal-TTI may be PCFICH, PHICH, PDCCH, EPDCCH, PUCCH, etc. in the existing LTE system.

In the present invention, the terms physical channel and signal in the conventional LTE or LTE-A system may be used interchangeably with data or control signals. For example, PDSCH is a physical channel through which normal-TTI data is transmitted, but in the present invention, PDSCH can be referred to as normal-TTI data, and sPDSCH is a physical channel through which shortened-TTI data is transmitted. -TTI data. Similarly, in the present invention, shortened-TTI data transmitted in downlink and uplink are referred to as sPDSCH and sPUSCH.

As described above, the present invention defines transmission/reception operations between the shortened-TTI terminal and the base station, and proposes a specific method for operating the existing terminal and the shortened-TTI terminal together in the same system. In the present invention, a normal-TTI terminal refers to a terminal that transmits and receives control information and data information in units of 1 ms or one subframe. The control information for the normal-TTI terminal is transmitted on a PDCCH mapped to up to 3 OFDM symbols in one subframe or on an EPDCCH mapped to a specific resource block in one subframe. Shortened-TTI terminal refers to a terminal that may transmit/receive in units of subframes like a normal-TTI terminal, or may transmit/receive in units smaller than subframes. Alternatively, it may be a terminal supporting only transmission and reception in units smaller than a subframe.

Hereinafter, in the present invention, the uplink scheduling acknowledgment signal and the downlink data signal are referred to as a first signal. Also, in the present invention, the uplink data signal for the uplink scheduling grant and the HARQ ACK/NACK for the downlink data signal are referred to as a second signal. In the present invention, among the signals transmitted by the base station to the terminal, if it is a signal expecting a response from the terminal, it may be the first signal, and the response signal of the terminal corresponding to the first signal may be the second signal. In addition, in the present invention, the service type of the first signal may belong to a category such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low-latency communications (URLLC).

Hereinafter, in the present invention, the TTI length of the first signal means the length of time the first signal is transmitted. Also, in the present invention, the TTI length of the second signal means the length of time the second signal is transmitted. Also, in the present invention, the second signal transmission timing is information on when the terminal transmits the second signal and when the base station receives the second signal, and may be referred to as the second signal transmission/reception timing.

If there is no mention of a TDD system in the present invention, an FDD system will be generally described. However, the method and apparatus in the present invention in an FDD system may be applied to a TDD system according to a simple modification.

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

Hereinafter, in the present invention, a terminal may mean a first type terminal unless otherwise stated. However, it will be clear whether the terminal is a first-type terminal or a second-type terminal according to context.

Hereinafter, in the present invention, a reference signal (RS) may refer to a signal promised and known between the base station and the terminal so that the base station or the terminal can measure the channel and use it for the reception operation. Hereinafter, the reference signal and RS may be used interchangeably.

In an embodiment of the present invention, the invention can be described by dividing the invention by the marks 1), 2), and 3).

[Embodiment 2-1]

Embodiment 2-1 provides a method of notifying whether RS is transmitted in downlink or uplink transmission. Whether the RS is transmitted may mean indicating that the RS is transmitted or not transmitted in the corresponding TTI.

In the conventional LTE system, a common cell RS or an RS for demodulation is transmitted in every subframe. However, since the ratio of RS in short TTI transmission may be greater than in long TTI transmission, it may be advantageous to omit RS transmission instead of transmitting RS in every TTI in short TTI transmission.

The base station informs the UE of whether RS is transmitted, 1) a method using a specific bit field of DCI, 2) after RS transmission is set by higher signaling, in multi-TTI scheduling, every even number or every odd number, Or at least one of a method in which RS is transmitted only in the first TTI, a method in which RS is transmitted every 0.5 ms or every 1 ms, 3) a method in which the length or position of a TTI scheduled in DCI is informed and the RS position is determined accordingly. More than one can be used.

In the method of 1) above, the base station and the terminal may promise that one specific bit or several bits of DCI indicates whether RS is transmitted. For example, in a DCI format for transmitting downlink scheduling or uplink scheduling information, when a specific bit is 0, RS is not transmitted and is omitted, and when the specific bit value is 1, RS is transmitted. When RS is omitted, data may be mapped to an area to which RS can be mapped and transmitted. In addition, in this case, it may be possible that the method of selecting the TBS varies depending on whether the RS is omitted. For example, in the case of 2-symbol TTI, the TBS when RS is omitted may be set to be twice that of TBS when RS is not omitted. FIG. 2F is a diagram illustrating a method of dividing one subframe into six 2-symbol TTIs in uplink transmission. Each TTI may be defined as 2f02, 2f04, 2f06, 2f08, 2f10, 2f12, and the first symbol in each TTI is determined to be used as RS. In addition, the last TTI (2f06, 2f12) of each slot consists of 3 symbols up to the RS transmission symbol, and the last symbol may be a symbol that cannot be transmitted. For example, when SRS is transmitted in the last symbol of a slot or in the last symbol of a subframe, it can be omitted. In the above case, when a bit for RS omission in DCI for scheduling for uplink data transmission indicates that RS is omitted, RS in each TTI is not transmitted, and uplink data may be transmitted in the corresponding symbol. . For example, if a specific bit of DCI indicates that RS is omitted in 2f04, RS is omitted and data is transmitted in both symbols. When data is transmitted in the two symbols, the TBS may be larger than when RS is transmitted and data is transmitted in only one symbol. In the above example, it has been described that whether or not RS is omitted is transmitted according to the absolute value of a specific bit of DCI, but it may be transmitted to the terminal in the form of a toggle. That is, a method of omitting if a specific bit of the current DCI is different from a specific bit value of the previous DCI compared to a specific bit of the previously transmitted DCI and not omitting if the same may be used.

In the method 2), when the RS transmission timing is set by the base station to the UE by higher level signaling, the RS transmission is performed according to the setting. For example, if RS omission is set by higher signaling, it may be possible to transmit RS only in every odd-numbered TTI only when multi-TTI scheduling is performed. Alternatively, when multiple TTI scheduling is performed, a method in which RS is transmitted only in the first TTI is also possible.

In the method of 3) above, the DCI may be a method of notifying the UE of the TTI length and position to be used in downlink or uplink in DCI, and thus the UE determines the RS position. For example, in uplink transmission, when the uplink TTI and RS location are determined as shown in FIGS. 2F and 2G, if the TTI location is scheduled, the UE can use the RS location according to the corresponding TTI.

2G and 2H are diagrams illustrating an example of a TTI position and an RS position in an uplink 2-symbol TTI transmission method. In the present invention, if the number of symbols including or not including RS symbols in the TTI is 2 symbols, it is assumed that the TTI is a 2-symbol TTI. 2G is a case in which one subframe includes 6 2-symbol TTIs. The RS used by each of the 6 TTIs may be already determined, and the 2nd TTI (2g04, 2g06) and the 5th TTI (2g12, 2g14) deliver which RS to use to the UE through DCI or higher signaling among the two, respectively. can be Meanwhile, as shown in FIG. 2H , a 2-symbol TTI may be defined and used in one subframe. Even in the above case, when the TTI location information is transmitted in scheduling, the UE may know which RS to use.

An example in this embodiment describes a method of notifying the terminal of whether RS is transmitted or the symbol position information at which the RS is transmitted using the case of uplink transmission, but whether the RS is transmitted in a similar way in the case of downlink transmission. Alternatively, it may be possible to inform the UE of symbol position information through which the RS is transmitted.

[Embodiment 2-2]

Embodiment 2-2 describes a method in which the base station notifies the terminal of the SC-FDMA symbol position through which an uplink reference signal (RS) is transmitted.

2K is a diagram illustrating an example of a structure of a shortened-TTI having 2 or 3 symbols included in one subframe in a TTI unit in uplink transmission. As in FIG. 2K , each shortened TTI in an uplink subframe may consist of 3,2,2,2,2,3 SC-FDMA symbols in turn. In addition, one subframe may have a shortened TTI of 6 2 symbols or 3 symbols, such as sTTI 0, sTTI 1, sTTI 2, sTTI 3, sTTI 4, sTTI 5 in turn.

Candidates for possible positions of SC-FMDA symbols in which uplink reference signals are transmitted in shortened TTI using 2 or 3 symbols are shown in Table 2b below.

[Table 2b]

Table 2b-(a) indicates possible options of possible RS symbol positions in 2-symbol shortened TTI. In one cell, R denotes an SC-FDMA symbol in which RS is transmitted, and D denotes an SC-FDMA symbol in which data, that is, sPUSCH, is transmitted. Therefore, in (a), option 1 is an option in which RS is not transmitted, option 2 is to transmit the RS of the corresponding shortened TTI to the last symbol of the previous shortened TTI, and option 3 is to RS to the first symbol of the shortened TTI. is transmitted, in option 4, the RS is transmitted to the last symbol of the corresponding shortened TTI, and in option 5, the RS of the corresponding shortened TTI is transmitted to the first symbol of the next shortened TTI.

Table 2b-(b) shows possible options of possible RS symbol positions in 3-symbol shortened TTI. In one cell, R denotes an SC-FDMA symbol in which RS is transmitted, and D denotes an SC-FDMA symbol in which data, that is, sPUSCH, is transmitted. Therefore, in (a), option 1 is an option in which RS is not transmitted, option 2 is to transmit the RS of the corresponding shortened TTI to the last symbol of the previous shortened TTI, and option 3 is to RS to the first symbol of the shortened TTI. is transmitted, in option 4, RS is transmitted in the second symbol of the corresponding shortened TTI, in option 5, RS is transmitted in the last symbol of the corresponding shortened TTI, and option 6 is transmitted in the first symbol of the next shortened TTI of the corresponding shortened TTI. RS is transmitted.

In order to use the above possible options, the base station may indicate the position of the uplink RS symbol transmitted together during uplink data transmission in some bitfields of DCI for transmitting the uplink data transmission grant. For example, when some 3 bits of DCI for uplink data transmission grant are used as a bit field indicating the position of the uplink RS symbol, the bit field may indicate the position of the uplink RS symbol as shown in Table 2c below.

[Table 2c]

As another example, when some 2 bits of DCI for uplink data transmission grant are used as bit fields indicating the location of uplink RS symbols, according to the location of the sTTI in one subframe, as shown in Table 2d or Table 2e below The bitfield may indicate the position of the uplink RS symbol. Table 2d is an example of using one shortened TTI including an option not including RS, and Table 2e is an example of using one shortened TTI without including an option not including RS. In addition, Table 2f is an example of using one shortened TTI so that RS does not come after the shortened TTI. Table 2f shows that when the RS is received later than the corresponding shortened TTI, the channel estimation is delayed and the data processing time may take longer in the base station, so the purpose of the RS may be to prevent the RS from coming after the corresponding shortened TTI.

[Table 2d]

[Table 2e]

[Table 2f]

Table 2d, Table 2e, and Table 2f show an example of selecting and using four of the options presented in Table 2c, and it is not necessary to be limited only to the tables. The present invention can be applied by being modified in various ways of selecting four. In addition, by selecting only two instead of four, some 1 bit of the DCI for the uplink data transmission grant is utilized as a bit field indicating the position of the uplink RS symbol, and the DCI indicates one of the two selected above. role can be used.

Alternatively, the base station may select only one of the options presented in Table 2c and inform the terminal of which option RS position to use in which shortened TTI of one subframe for higher signaling. In the above example, in DCI for an uplink data transmission grant, a bit field indicating the location of the RS may not be required. Or in the example above, in the DCI for the uplink data transmission grant, the bit field indicating the location of the RS has 1 bit, and when the 1 bit transmits uplink data in the shortened TTI, the RS is transmitted at the higher signaled position. , otherwise it may indicate whether to omit transmission of RS and transmit data in the corresponding symbol.

Alternatively, Table 2f can be used by fixing options indicating the SC-FDMA symbol position for transmitting data and RS of shortened TTI including 2 or 3 symbols as shown in Table 2g below.

[Table 2g]

As another example, among the options in Table 2c, the base station transmits two or four of the options to the terminal by higher signaling, and the terminal indicates the option indicated by 1 bit or 2 bits of DCI among the two or four of the options of the RS. information can be determined. Table 2h below is a method of determining the DCI bit field with 1 bit among the two higher signaled options, and Table 2i below shows a method of determining the DCI bit field with 2 bits among the four options signaled above the upper level.

[Table 2h]

[Table 2i]

When the terminal receives a DCI including grant information for higher signaling or uplink data transmission for shortened TTI as described above, a predetermined bitfield of the received DCI is interpreted as position information of a symbol including an uplink RS, When transmitting the uplink data, RS is transmitted at the position of the RS symbol indicated by the DCI, and data is transmitted in other shortened TTI symbols or symbols.

As described above, the base station transmits DCI including grant information for upper signaling or uplink data transmission for shortened TTI to the terminal, and when the corresponding uplink data is received, RS in the symbol of the position indicated by the DCI It is assumed that is received and channel estimation is performed. Data demodulation is performed using the estimated channel.

In order to carry out the above embodiments of the present invention, the transmitting unit, the receiving unit, and the processing unit of the terminal and the base station are shown in FIGS. 2I and 2J, respectively. A method of transmitting and receiving a base station and a terminal is shown in order to determine the transmission/reception timing of the second signal and to perform an operation according thereto from 1) to 3) of the second embodiment. , the transmitter must operate according to each embodiment.

Specifically, FIG. 2I is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present invention. As shown in FIG. 2I, the terminal of the present invention may include a terminal receiving unit 2i00, a terminal transmitting unit 2i04, and a terminal processing unit 2i02. In an embodiment of the present invention, the terminal receiving unit 2i00 and the terminal collectively refer to the transmitting unit 2i04, and may be referred to as a transceiver. The transceiver may transmit/receive a signal to/from the base station. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel, output it to the terminal processing unit 2i02, and transmit the signal output from the terminal processing unit 2i02 through a wireless channel. The terminal processing unit 2i02 may control a series of processes so that the terminal can operate according to the above-described embodiment of the present invention. For example, the terminal receiving unit 2i00 receives a signal including whether or not RS transmission is omitted or an RS symbol position from the base station, and the terminal processing unit 2i02 can control whether or not to transmit RS and interpret the RS symbol position from the signal. there is. Thereafter, the terminal transmitter 2i04 uses the transmitted information to transmit RS at a designated symbol position or perform uplink data transmission omitting RS transmission.

2J is a block diagram illustrating an internal structure of a base station according to an embodiment of the present invention. As shown in FIG. 2J, the base station of the present invention may include a base station receiving unit 2j01, a base station transmitting unit 2j05, and a base station processing unit 2j03. In the embodiment of the present invention, the base station receiving unit 2j01 and the base station transmitting unit 2j05 may be collectively referred to as a transceiver. The transceiver may transmit/receive a signal to/from the terminal. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel and output it to the base station processing unit 2j03, and transmit the signal output from the terminal processing unit 2j03 through the wireless channel. The base station processing unit 2j03 may control a series of processes so that the base station can operate according to the above-described embodiment of the present invention. For example, the base station processing unit 2j03 may control whether to skip RS transmission or to generate control information including an RS symbol position. Thereafter, the base station transmitter 2j05 transmits the control signal, and the base station receiver 2j01 receives the uplink transmission according to the setting.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are merely presented as specific examples to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. That is, it will be apparent to those of ordinary skill in the art to which the present invention pertains that other modified examples can be implemented based on the technical spirit of the present invention. In addition, parts of the above embodiments may be operated in combination with each other as needed. For example, the method 1) and the method 3) of the 2-1 embodiment of the present invention may be combined to operate the base station and the terminal. In addition, although the above embodiments have been presented based on the LTE system, other modifications based on the technical idea of the embodiment may be implemented in other systems such as 5G or NR systems.

<Third embodiment>

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

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

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

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the possessor of 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.

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

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

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

A wireless communication system, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), 3GPP2 HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE 802.16e, such as communication standards such as communication standards, such as high-speed, high-quality packet data service is developed as a broadband wireless communication system are doing In addition, a communication standard of 5G or NR (new radio) is being made as a 5G wireless communication system.

In this way, in a wireless communication system including the 5th generation, at least one service of enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low-latency communications (URLLC) may be provided to the terminal. there is. In this case, the services may be provided to the same terminal during the same time period. In all the following embodiments of the present invention, eMBB may be a high-speed transmission of high-capacity data, mMTC may be a service that minimizes terminal power and multiple terminals are connected, and URLLC may be a service targeting high reliability and low latency, but is not limited thereto. In addition, in all the following embodiments of the present invention, it may be assumed that the URLLC service transmission time is shorter than the eMBB and mMTC service transmission time, but is not limited thereto. The three services may be major scenarios in an LTE system or a system such as 5G/NR (new radio, next radio) after LTE.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, when it is determined that a detailed description of a function or configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification. Hereinafter, the base station is a subject that sets some or all control information of the terminal and performs resource allocation, eNode B, Node B, BS (Base Station), radio access unit, base station controller, TRP (Transmission and Reception Point) or It may be at least one of the nodes on the network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function.

In the present invention, a downlink (DL) is a wireless transmission path of a signal transmitted from a base station to a terminal, and an uplink (UL) is a wireless transmission path of a signal transmitted from a terminal to a flag station. In addition, although an embodiment of the present invention will be described below using an LTE or LTE-A system as an example, the embodiment of the present invention may be applied to other communication systems having a similar technical background or channel type. For example, 5G mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in this. In addition, the embodiments of the present invention can be applied to other communication systems through some modifications within the scope of the present invention as judged by a person having skilled technical knowledge.

As a representative example of the broadband wireless communication system, in the LTE system, an Orthogonal Frequency Division Multiplexing (OFDM) scheme is employed in a Downlink (DL), and Single Carrier Frequency Division Multiple (SC-FDMA) is used in an Uplink (UL). Access) method is adopted. Uplink refers to a radio link in which a 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 base station Refers to a radio link that transmits data or control signals to this terminal.The multiple access method as described above is designed so that time-frequency resources for transmitting data or control information for each user do not overlap each other, that is, orthogonality is By assigning and operating so as to be established, each user's data or control information can be distinguished.

The LTE system employs a Hybrid Automatic Repeat reQuest (HARQ) method for retransmitting the corresponding data in the physical layer when a decoding failure occurs in the initial transmission. In the HARQ scheme, when the receiver fails to correctly decode (decode) data, the receiver transmits information (Negative Acknowledgment; NACK) notifying the transmitter of decoding failure so that the transmitter can retransmit the data in the physical layer. The receiver combines the data retransmitted by the transmitter with the previously unsuccessful data to improve data reception performance. In addition, when the receiver correctly decodes the data, the transmitter may transmit new data by transmitting an acknowledgment (ACK) informing the transmitter of decoding success.

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

Referring to FIG. 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, in which N _symb (3a-102) OFDM symbols are gathered to form one slot (3a-106), and two slots are gathered to form one subframe (3a-105). make up The length of the slot is 0.5 ms, and the length of the subframe is 1.0 ms. In addition, the radio frames 3a-114 are time domain sections composed 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 N _BW (3a-104) subcarriers. However, such specific numerical values may be variably applied.

A basic unit of a resource in the time-frequency domain is a resource element (3a-112, Resource Element; RE) and may be represented by an OFDM symbol index and a subcarrier index. The resource blocks 3a-108 (Resource Block; RB or Physical Resource Block; PRB) have N _symb (3a-102) consecutive OFDM symbols in the time domain and N _RB (3a-110) consecutive subcarriers in the frequency domain. can be defined as Accordingly, one RB 3a-108 in one slot may include N _symb x N _RB REs 3a-112. In general, the minimum allocation unit in the frequency domain of data is the RB. In the LTE system, in general, N _symb = 7, N _RB = 12, and N _BW and N _RB 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 operate by defining six transmission bandwidths. In the case of an FDD system operating by dividing downlink and uplink by frequency, the downlink transmission bandwidth and the uplink transmission bandwidth may be different from each other. The channel bandwidth represents an RF bandwidth corresponding to a system transmission bandwidth. Table 3a below shows the correspondence between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, an LTE system having a 10 MHz channel bandwidth may be configured with 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 in the subframe. In an embodiment, generally N = {1, 2, 3}. Accordingly, the N value may be variably applied to each subframe according to the amount of control information to be transmitted in the current subframe. The transmitted control information may include a control channel transmission interval 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 whether it is scheduling information for uplink data (UL grant) or scheduling information for downlink data (DL grant) according to each format, whether it is a compact DCI with a small size of control information , whether spatial multiplexing using multiple antennas is applied, whether DCI for power control, etc. may be indicated. 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 allocates resources in a RBG (resource block group) unit by applying a bitmap method. The basic unit of scheduling in the LTE system is an RB expressed by time and frequency domain resources, and the RBG is composed of a plurality of RBs and becomes a basic unit of scheduling in the type 0 scheme. Type 1 allows allocating a specific RB within an RBG.

- Resource block assignment: indicates an RB allocated for data transmission. The resource to be expressed is determined according to the system bandwidth and resource allocation method.

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

- HARQ process number (HARQ process number): indicates the process number of HARQ.

- New data indicator (New data indicator): indicates whether the HARQ initial transmission or retransmission.

- Redundancy version: indicates a redundancy version of HARQ.

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

The DCI is a physical downlink control channel (PDCCH) that is a downlink physical control channel (or control information, hereinafter, to be used in combination) or EPDCCH (Enhanced PDCCH) (or enhanced control information, hereinafter) through a channel coding and modulation process. It should be mixed and used).

In general, the DCI is independently scrambled with a specific Radio Network Temporary Identifier (RNTI) (or UE identifier) for each UE, a cyclic redundancy check (CRC) is added, and after channel coding, each is composed of an independent PDCCH. is sent 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 over the entire system transmission band.

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

Among the control information constituting the DCI, through the MCS, the base station notifies the terminal of the modulation scheme 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 a size before channel coding for error correction is applied to data (transport block, TB) to be transmitted by the base station.

Modulation schemes supported by the LTE system are Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (16QAM), and 64QAM, and each modulation order (Qm) corresponds to 2, 4, and 6. That is, in case of QPSK modulation, 2 bits per symbol, in case of 16QAM modulation, 4 bits per symbol, and in case of 64QAM modulation, 6 bits per symbol may be transmitted. In addition, a modulation scheme of 256QAM or more may be used according to system modification.

3B is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in an uplink in an LTE-A system.

Referring to FIG. 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 1b-202, and N _symb ^UL SC-FDMA symbols may be gathered to form one slot 3b-206. And two slots are gathered to configure one subframe (1b-205). The minimum transmission unit in the frequency domain is a subcarrier, and the entire system transmission bandwidth (1b-204) consists of a total of N _BW subcarriers. N _BW may have a value proportional to the system transmission band.

A basic unit of a resource in the time-frequency domain is a resource element (RE, 1b-212) and may be defined as an SC-FDMA symbol index and a subcarrier index. A resource block pair (1b-208, Resource Block pair; RB pair) may be defined as N _symb ^UL consecutive SC-FDMA symbols in the time domain and NscRB consecutive subcarriers in the frequency domain. Accordingly, one RB consists of N _symb ^UL x NscRB REs. In general, the minimum transmission unit of data or control information is an RB unit. In the case of PUCCH, it is mapped to a frequency domain corresponding to 1RB and transmitted for 1 subframe.

In the LTE system, PUCCH or PUSCH which is an uplink physical channel through which HARQ ACK/NACK corresponding to PDSCH, which is a physical channel for downlink data transmission, or PDCCH/EPDDCH including semi-persistent scheduling release (SPS release) is transmitted. A timing relationship of can be defined. For example, in an LTE system operating in frequency division duplex (FDD), 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 scheme in which a data retransmission time point is not fixed. That is, when the HARQ NACK is fed back from the terminal for the initial transmission data transmitted by the base station, the base station freely determines the transmission time of the retransmission data by the scheduling operation. For the HARQ operation, after buffering data determined to be an error as a result of decoding received data, the UE may perform combining with the next retransmission data.

Upon receiving the PDSCH including downlink data transmitted from the base station in subframe n, the terminal transmits 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 In this case, k may be defined differently according to the FDD or time division duplex (TDD) of the LTE system and its subframe settings. For example, in the case of an FDD LTE system, k is fixed to 4. Meanwhile, in the case of the TDD LTE system, k may be changed according to the subframe configuration and the subframe number. In addition, when data is transmitted through a plurality of carriers, a value of k may be applied differently according to the TDD setting of each carrier.

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

When the terminal receives a PDCCH including uplink scheduling control information transmitted from the base station in subframe n or a PHICH in which downlink HARQ ACK/NACK is transmitted, uplink data corresponding to the control information in subframe n+k It is transmitted through PUSCH. In this case, k may be defined differently according to the FDD or time division duplex (TDD) 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 the TDD LTE system, k may be changed according to the subframe configuration and the subframe number. In addition, when data is transmitted through a plurality of carriers, a value of k may be applied differently according to the TDD setting of each carrier.

And when the UE receives a PHICH including downlink HARQ ACK/NACK-related information from the base station in subframe i, the PHICH corresponds to the PUSCH transmitted by the UE in subframe i-k. In this case, k may be defined differently according to the FDD or TDD of the LTE system and its configuration. For example, in the case of an FDD LTE system, k is fixed to 4. Meanwhile, in the case of the TDD LTE system, k may be changed according to the subframe configuration and the subframe number. Also, when data is transmitted through a plurality of carriers, a value of k may be applied differently according to the TDD setting of each carrier.

The description of the wireless communication system has been described 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 another wireless communication system in an embodiment, the value of k may be changed and applied to a system using a modulation scheme corresponding to FDD.

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

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

First, in FIG. 3c , data for eMBB, URLLC, and mMTC are allocated in the entire system frequency band 3c-300. When eMBB (3c-301) and mMTC (3c-309) are allocated in a specific frequency band and are transmitted, when URLLC data (3c-303, 3c-305, 3c-307) is generated and transmission is required, eMBB (3c- 301) and mMTC (3c-309) may vacate an already allocated portion or transmit URLLC data (3c-303, 3c-305, 3c-307) without transmission. Among the above services, since it is necessary to reduce the delay time of URLLC, URLLC data may be allocated (3c-303, 3c-305, 3c-307) to a part of the resource 3c-301 to which the eMBB is allocated and transmitted. Of course, when URLLC is additionally allocated and transmitted in the resource to which the eMBB is allocated, the eMBB data may not be transmitted in the overlapping frequency-time resource, and thus the transmission performance of the eMBB data may be lowered. That is, in the above case, eMBB data transmission failure may occur due to URLLC allocation.

In FIG. 3D , the entire system frequency band 3d-400 may be divided and used for service and data transmission in each subband 3d-402, 3d-404, and 3d-406. Information related to the subband configuration may be predetermined, and this information may be transmitted from the base station to the terminal through higher level signaling. Alternatively, the information related to the subband may be arbitrarily divided by a base station or a network node to provide services to the terminal without transmission of additional subband configuration information. In FIG. 3d , subband 3d-402 is used for eMBB data transmission, subband 3d-404 is used for URLLC data transmission, and subband 3d-406 is used for mMTC data transmission.

In all embodiments, the length of the transmission time interval (TTI) used for URLLC transmission will be described assuming that it is shorter than the TTI length used for eMBB or mMTC transmission. The same case as the used TTI length is also applicable. In addition, the response of URLLC-related information can be transmitted faster than the response time of eMBB or mMTC, and thus information can be transmitted/received with low delay.

The eMBB service described below is referred to as a first type service, data for eMBB is referred to as first type data, and control information for eMBB is referred to as first type control information. The first type service, first type control information, or first type data is not limited to eMBB, and may correspond to a case where at least one of high-speed data transmission and broadband transmission is required. Also, URLLC service is referred to as a second type service, URLLC control information is referred to as second type control information, and URLLC data is referred to as second type data. The second type service, the second type control information, or the second type data is not limited to URLLC and is at least one of a case where a low latency time is required or a high reliability transmission is required, or a low latency time and high reliability are required at the same time The above can be applied to other services or systems that require it. In addition, the mMTC service is referred to as a third type service, the mMTC control information is referred to as the third type control information, and the mMTC data is referred to as the third type data. The third type service The third type control information or the third type data is not limited to mMTC, but at least one of low speed or wide coverage, low power, intermittent data transmission, and small size data transmission is required. can Also, when describing the embodiment, it may be understood that the first type service includes or does not include the third type service.

The structure of a physical layer channel used according to each service type to transmit at least one of the three services, control information, or data may be different. For example, at least one of a length of a transmission time interval (TTI), an allocation unit of a frequency or time resource, a structure of a control channel, and a data mapping method may be different. At this time, although three different types of services, control information, and data have been described above as an example, more types of services, control information, and data may exist, and in this case, the contents of the present invention may also be applied. In addition, in the embodiment of the present invention, as a judgment of a person with skilled technical knowledge, the control information for the service and the data for the service are not separately described in a range that does not significantly deviate from the scope of the present invention, and the control information is included in the data for the service. The present invention can be applied as it is considered to be included.

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

As described above, the embodiment defines transmission/reception operations between a terminal and a base station for a first type, a second type, and a third type service or data transmission, and sets the terminals receiving different types of services, control information, or data scheduling. We propose a specific method for operating together in the same system. In the present invention, the first-type, second-type, and third-type terminals refer to terminals that have received the first-type, second-type, and third-type service 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 different terminals. In addition, in the terminal supporting transmission and reception of one or more service types in the above embodiment, at least one service of the first type, the second type, and the third type is operated in the same cell or carrier, or each service is operated in different cells or carriers Even when the type is operated, the contents of the present invention can be applied.

In the following embodiment, at least one of an uplink scheduling grant signal and a downlink data signal is referred to as a first signal. Also, in the present invention, at least one of an uplink data signal for uplink scheduling configuration and a response signal (or HARQ ACK/NACK signal) to the downlink data signal is referred to as a second signal. In the embodiment, among the signals transmitted by the base station to the terminal, if a signal is expected to receive a response from the terminal, it may be the first signal, and the response signal of the terminal corresponding to the first signal may be the second signal. Also, 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.

In the following embodiment, the TTI length of the first signal is a time value related to transmission of the first signal, and may indicate the length of time during 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 may indicate the length of time that the second signal is transmitted, and the TTI length of the third signal is related to the transmission of the third signal. The time value may indicate the length of time the third signal is transmitted. In addition, in the present invention, the first signal, the second signal, or the third signal transmission and reception timing is when the terminal transmits the first signal, the second signal, or the third signal, and the base station transmits the first signal, the second signal , or information on when to receive the third signal or when to transmit a response or feedback (eg, ACK/NACK information) to the received signal, which is the first signal, the second signal, or the third signal It can be said that the transmission/reception timing of In this case, the first signal, the second signal, and the third signal may be regarded as signals for the first type service, the second type service, and the third type service. In this case, the TTI lengths of the first signal, the second signal, and the third signal, and at least one of the first signal, the second signal, and the transmission/reception timing of the third signal may be set differently. For example, the TTI length of the first signal may be the same as the TTI length of the second signal, but may be set longer than the TTI length of the third signal. As another example, the first signal and the second signal transmission/reception timing may be set to n+4, but the transmission/reception timing of the third signal may be shorter than the transmission/reception timing, for example, set to n+2.

In addition, in the following embodiment, assuming that the terminal transmits the second signal at the n+k-th TTI when the base station transmits the first signal at the n-th TTI, the base station informs the terminal of the timing to transmit the second signal is the same as telling the value of k. Alternatively, if it is assumed that the terminal transmits the second signal at the n+t+a-th TTI when the base station transmits the first signal at the n-th TTI, the fact that the base station informs the terminal of the timing to transmit the second signal is in advance. It is equivalent to reporting the offset value a based on the value t defined in or derived by a predefined method. In this case, the t value may be predefined as various values as well as t=4 mentioned in the present invention, or may be derived in a predefined manner.

In addition, the technology proposed in the present invention is applicable not only to FDD and TDD systems but also to a new type of duplex mode (eg, LTE frame structure type 3).

Hereinafter, in the present invention, upper signaling refers to a signal transmission method in which the base station uses the downlink data channel of the physical layer to the terminal, or from the terminal to the base station using the uplink data channel of the physical layer, RRC signaling, or PDCP. It means that the signal is transmitted between the base station and the terminal through at least one of signaling or a MAC control element (MAC CE).

Hereinafter, in an embodiment of the present invention, an uplink transmission resource allocation method for reducing a delay between transmission of uplink transmission configuration information and configured uplink transmission in providing one or more services including eMBB, mMTC, URLLC, etc. to a terminal will be described. do. In addition, the embodiment of the present invention will be mainly described assuming that a base station and a terminal performing uplink transmission through an unlicensed band, but embodiments of the present invention operate between a base station and a terminal performing uplink transmission through a licensed band is also applicable to

In general, the base station sets (scheduling) a specific transmission time interval (hereinafter referred to as TTI) and frequency resource area so that the terminal can transmit uplink data or control information corresponding to eMBB, mMTC, URLLC, etc. For example, the base station may be configured to perform uplink transmission in subframe n+k (k≥0) to a specific terminal through a downlink control channel in subframe n. In other words, the base station transmits uplink transmission configuration information to a terminal requiring uplink transmission through a downlink control channel in subframe n, and the terminal receiving the uplink transmission configuration information sets the uplink transmission configuration information in the uplink transmission configuration information. Uplink data or control information may be transmitted to a base station (or another terminal) by using a time and frequency resource domain. In this case, the terminal having data or control information to be transmitted through the uplink may transmit scheduling request information to the base station or request the base station to transmit the uplink transmission configuration information to the terminal through a random access process.

In other words, the uplink transmission of a general terminal may be performed in the following three steps. In this case, uplink transmission through three steps is only one example, and uplink transmission through more or fewer steps than the steps described in this example is also possible.

Step 1: A terminal that has generated data or control information to be transmitted through the uplink requests an uplink transmission setup from the base station to the base station through a valid uplink resource capable of transmitting an uplink transmission setup request. In this case, at least one of a time resource and a frequency resource for requesting the uplink transmission configuration may be predefined or configured through a higher-order signal.

Step 2: The base station receiving the uplink transmission configuration request from the terminal transmits uplink transmission configuration information to the terminal through the downlink control channel to configure uplink transmission.

Step 3: The terminal configured for uplink transmission from the base station performs uplink transmission using uplink transmission configuration information set by the base station.

That is, a terminal having data or control information to be transmitted through the uplink has a transmission delay of more than a certain time in transmitting the uplink information. For example, in a terminal having uplink transmission data generated at time n, when the uplink transmission configuration request resource is set to a period of 5 ms, a delay of up to 5 ms may occur in transmitting the uplink transmission configuration request information. In addition, if a transmission delay (eg, 1 ms) between the uplink configuration control information reception time and the configured uplink transmission start time is required, a transmission delay of at least 6 ms is unavoidable when the terminal starts uplink transmission. Accordingly, the present invention proposes a method in which a terminal desiring to perform an uplink signal transmission operation can perform uplink transmission without receiving separate uplink transmission configuration information from a base station.

Therefore, in the present invention, when the terminal intends to perform uplink transmission, it uses a radio resource defined in advance by the base station or set through a broadcast channel that transmits an upper signal or system information (eg System Information Block, SIM). Thus, a method for performing uplink transmission without a separate uplink transmission configuration from the base station will be described.

In general, for uplink signal transmission in the terminal, after receiving configuration information about uplink transmission from the base station, the base station may perform uplink transmission using time and frequency resources set for uplink transmission of the terminal. there is.

In this embodiment, in the base station and the terminal performing wireless communication in the unlicensed band, that is, after performing a channel access procedure (or listen-before-talk (LBT)) to occupy and transmit the unlicensed band In a base station and a terminal capable of transmitting a signal, a method for enabling the terminal to perform uplink transmission through the unlicensed band without receiving uplink transmission configuration information from the base station is proposed.

A base station and a terminal performing wireless communication in an unlicensed band perform a channel access procedure defined in advance according to a frequency band, a country, etc. or defined in a corresponding wireless communication standard for coexistence with other wireless devices, and then A signal may or may not be transmitted depending on the result of performing the channel access procedure. For example, the base station or the terminal detects (eg, compares the strength of a received signal) a channel for performing the wireless communication during a fixed period or a period that varies according to a rule. If it is determined that the channel is idle for the set time (for example, when the strength of the received signal received by the transmitting device during the time is predefined or smaller than a threshold set according to a rule), A base station or a terminal may perform communication using the channel. If it is determined that the channel is not in the idle state for the set time (eg, when the strength of the received signal during the time is predefined or greater than a threshold set according to a rule), the base station or the terminal No communication is performed using the channel. Therefore, if the base station and the terminal perform uplink transmission through step 3 as described above, a channel access procedure for uplink control information and data transmission is performed in steps 1 and 3, and the base station performs downlink in step 2 A channel access procedure for transmission is performed. Therefore, if the terminal performing wireless communication through the unlicensed band uses the method capable of performing uplink transmission without receiving separate uplink transmission configuration information from the base station proposed by the present invention, only the channel access procedure in step 3 is used. is required, so that uplink transmission can be performed more efficiently. Hereinafter, in the present invention, as described above, when the terminal performs uplink transmission without receiving separate uplink transmission configuration information from the base station, it is referred to as grant-free transmission. In this case, in the grant-free transmission, the terminal not only performs uplink transmission without receiving any configuration related to uplink transmission configuration information from the base station, but also at least one or more information (for example, , all or part of information on time or frequency resources in which grant-free transmission is possible (eg, start frequency information in which grant-free transmission is possible) is predefined between the base station and the terminal, or the terminal transmits an upper signal from the base station This includes using information set or received through the terminal, received by the terminal through system information transmitted through the base station through a broadcast channel, or configured through the downlink control channel of the base station.

The base station may set the uplink transmission scheme of the terminal through system information transmission through a higher-order signal or broadcast channel, a downlink control channel, or the like to the terminal. In this case, the uplink transmission method of the terminal is a grant-based transmission method in which the terminal receives uplink transmission configuration information from the base station and performs uplink transmission according to the received uplink transmission configuration, in which the terminal receives a separate uplink from the base station. It can be classified into a grant-free transmission scheme capable of performing uplink transmission without receiving link transmission configuration information. In this case, it is possible not only for the terminal to operate by being divided into a grant-based transmission method or a grant-free transmission method, but also for the terminal to support both the grant-based transmission method and the grant-free transmission method. For example, when the terminal configured in the grant-free transmission method receives uplink transmission configuration information through the downlink control channel from the base station, the terminal uses the uplink transmission configuration information most recently received from the base station to grant Uplink transmission may be performed in a -based transmission method. In this case, it is also possible for the terminal to perform uplink transmission using only a part of uplink transmission configuration information most recently received from the base station.

The base station may configure an uplink transmission scheme in the base station or cell to the terminal through a higher-order signal. A method for the base station to set the uplink transmission scheme of the terminal through the upper signal to the terminal is as follows. The base station adds a field related to the uplink transmission method of the terminal to the RRC configuration information for a specific base station or cell (or SCell, or transmission and reception point (TRP)) to the terminal, for example, a grantfreeULtransmission field, and the field value By setting it to true, the uplink transmission scheme for the cell can be set to the UE as a grant-free transmission scheme. In this case, the terminal receiving the RRC field value as false may determine that the uplink transmission method for the cell is set to a grant-based transmission method in which uplink control information is received and transmitted from the base station. The distinction between the RRC field and the uplink transmission method is only one example and is not limited thereto.

The base station may transmit an uplink transmission scheme in the base station or cell to one or more terminals through system information transmission through a broadcast channel of the base station or cell. In this case, a method for the base station to transmit or set an uplink transmission scheme of the terminal through transmission of system information through a broadcast channel to the terminal is as follows. A base station or cell (or SCell, or transmission and reception point (TRP)) periodically or aperiodically transmits or broadcasts system information (eg, SIB: system information block) information for the cell to one or more terminals ( can be broadcast). In this case, the broadcast channel means a channel that a plurality of terminals can receive through one predefined identifier (eg, system information RNTI). In this case, the system information additionally includes not only the configuration related to the uplink transmission scheme of the cell, but also configuration information related to the grant-free transmission scheme, for example, at least one or more of grant-free transmission time and frequency resource information. can do. If the uplink transmission method of the cell is set to a grant-based transmission method, grant-free transmission time and frequency resource information are not included, or grant-free transmission time and frequency resource information are included. Even if there is, the UE may ignore it.

The base station may set the uplink transmission method of the terminal through the downlink control channel of the base station. A method for the base station to set the uplink transmission method of the terminal through the downlink control channel of the base station is as follows. Channel or cell-specific search space) or a group common control channel (group common control channel or group-specific search space) may be transmitted by adding an uplink transmission method field. In this case, the common control channel or group common control channel means that all or a specific group of terminals receive the same control information from the base station through an identifier (eg, group RNTI) defined in advance for specific terminals or set by the base station. . For example, the base station can set the uplink transmission method of the terminal included in the group by adding a field related to the group's uplink transmission method among the uplink transmission information transmitted in the group common control channel. there is. For example, a field for transmitting information about an uplink transmission method or type field or uplink transmission setting presence/absence, for example, a 1-bit field is added, and when the field is set to 1, the terminal receives the control channel They may perform uplink transmission to the base station or cell in a grant-free transmission scheme. In this case, when the field is set to 0, terminals receiving the control channel may perform uplink transmission to the base station or cell in a grant-based transmission scheme. In this case, the added field and the setting method of the field are only one example, and it is also possible to set the field to 1 bit or more. For example, by adding a 2-bit field, a grant-free transmission scheme, a grant-based transmission scheme, a mix of grant-free transmission, and a grant-based transmission scheme can be distinguished to set uplink transmission schemes of terminals.

As described above, the terminal having the uplink transmission method configured as the grant-free transmission method at least one of the variables related to uplink transmission (eg, time resource domain, frequency resource domain, MCS, PMI, RI, etc.) The above variables may be selected and transmitted by the terminal. For example, a base station that has set a grant-free transmission scheme to the terminal as shown in FIG. 3E uses one of the various configuration methods described in the above embodiment for periodic time resource region information in which grant-free uplink transmission is possible. In addition to the time domain information in which grant-free transmission is possible, the terminal sets variables that require additional configuration when performing uplink transmission, for example, a frequency resource domain in which uplink transmission is actually performed. You can choose to send it. In this case, the base station provides a selectable candidate or set value among uplink transmission related variables that the terminal can select, for example, MCS set (QPSK, 16QAM), frequency start region information in which grant-free transmission is possible, etc. to the terminal in advance. It is also possible to select a setting value to be used for uplink transmission by the terminal from among the set candidate groups. In this case, the above example of setting the time resource region in advance and arbitrarily selecting the frequency resource is only one example, and the terminal may set all or part of the variables including variables other than the variables necessary for uplink transmission mentioned above. It is also possible to choose.

A base station or a terminal in a cell operating in an unlicensed band may perform different channel access procedures according to an uplink transmission scheme configured by the base station. The base station and the terminal (or transmitting device) operating in the unlicensed band must perform a channel detection operation or a channel access procedure for the unlicensed band before transmitting a downlink signal or an uplink signal to the unlicensed band. In this case, the requirement for the channel access procedure may be defined in advance according to a frequency band, a country, or the like, or defined in a corresponding wireless communication standard.

In general, the channel access procedure in a transmitting device that intends to transmit a signal through an unlicensed band measures the strength of a received signal in the band for a set time according to a rule defined in advance for the unlicensed band to transmit the signal, Comparing the measured signal strength with a threshold value set according to a predefined rule, it consists of a procedure of confirming whether the unlicensed band can be used. If the strength of the signal received during the set time is less than the set threshold value, the transmitting device may determine that the unlicensed band is in an idle state and transmit a signal through the unlicensed band. If the strength of the signal received for the set time is greater than the set threshold, the transmitting device determines that the unlicensed band is occupied by other devices and does not transmit a signal through the unlicensed band, and the band The channel access procedure may be repeatedly performed until it is determined that it is in an idle state.

A channel access procedure in a wireless communication system operating in a general unlicensed band is largely divided into a downlink channel access procedure in a base station or cell to transmit a downlink signal and an uplink channel access procedure in a terminal to transmit an uplink signal. It can be divided into two categories.

In this case, in general, the base station transmits a downlink control channel and a data channel through an unlicensed band determined to be in an idle state through a downlink channel access procedure, and if there is a terminal requiring uplink transmission through the unlicensed band, The base station may configure uplink transmission to the terminal through a downlink control channel. As described above, the terminal configured for uplink transmission for the unlicensed band performs a channel access procedure defined in advance for the configured uplink transmission or configured through uplink transmission configuration information from the base station, and then performs the configured uplink transmission. may or may not perform.

In other words, in the case of a terminal performing uplink transmission through a grant-based uplink transmission scheme through an unlicensed band, a downlink channel access procedure for the base station to transmit uplink transmission configuration information and performing the configured uplink transmission Uplink channel access procedure for each is required. On the other hand, in the case of a terminal configured with a grant-free uplink transmission scheme, after performing an uplink channel access procedure without the need for a downlink channel access procedure of a base station in an unlicensed band for uplink signal transmission, the configured uplink transmission is performed. may or may not perform. Accordingly, at least one or more of variables required for a channel access procedure of a terminal performing uplink transmission according to a grant-based uplink transmission scheme in an unlicensed band and a terminal performing uplink transmission according to a grant-free uplink transmission scheme Variables can be set differently. Through this, the base station sets differently the channel access procedure of the terminal that has received the uplink transmission configuration information and the channel access procedure of the terminal that can perform uplink transmission without receiving separate uplink transmission configuration information from the base station, so that the grant-based uplink Link transmission may take precedence over grant-free-based uplink transmission to occupy an unlicensed band. In this case, it is also possible to allow grant-free-based uplink transmission to occupy an unlicensed band in preference to grant-based uplink transmission. The priority for the grant-based and grant-free transmission may be set differently depending on the setting of the base station, but in the present invention, in general, the grant-based transmission requiring a downlink channel access procedure for the unlicensed band of the base station is used. It is assumed that the channel access priority for the channel access is higher than the channel access priority for the grant-free transmission.

More specifically, the channel access procedure for uplink transmission of the terminal in which the grant-based uplink transmission scheme is set from the base station (hereinafter, the first type of channel access procedure) is performed by the base station before the uplink transmission of the terminal is performed. Since this downlink channel access operation is performed, among the configuration variables required to perform a channel access procedure for uplink transmission of a terminal configured in a grant-free uplink transmission scheme from a base station (hereinafter, a second type of channel access procedure) , at least one variable may be set to a value for facilitating occupation of the unlicensed band channel of the terminal in which the grant-based uplink transmission is configured or in a direction to increase the channel access probability. At this time, the terminal receives a variable set differently according to the grant-based uplink transmission method and the grant-free uplink transmission method from the base station through an upper signal, or uplink scheduling information (or UL grant) or one or more terminals or The variable may be set through a downlink control channel (PDCCH) or a group common control channel ((Group) common PDCCH) through which group common control information transmitted to group terminals is transmitted. In addition, the terminal receives configuration parameters necessary for performing the second type of channel access procedure from the base station through a higher-order signal (eg, RRC configuration), and transmits an uplink signal without receiving uplink transmission configuration information from the base station. In this case, when a channel access procedure for uplink transmission is performed according to the configured uplink channel access procedure of the second type, and an uplink signal is transmitted after receiving uplink transmission configuration information from the base station, the terminal At least one first type of uplink channel connection related configuration variable may be set through the received uplink transmission configuration information, and the first type of uplink channel access procedure may be performed according to the configuration value.

For example, in performing the first type of channel access procedure, a threshold value (or energy detection threshold) of the strength of the received signal for determining the idle state of the unlicensed band is applied in the second type of channel access procedure. The probability of determining that the unlicensed band is idle through the first type of channel access procedure, or the probability of channel access when the first type of channel access procedure is performed is set to a value greater than the threshold value of the strength It may be set to be larger than when the second type of channel access procedure is performed.

As another example, the time required to determine the idle state of the unlicensed band in performing the first type of channel access procedure, that is, the terminal measures the strength of the received signal to determine whether the unlicensed band is idle. and an average time or absolute time value for comparing the measured strength of the received signal with a threshold value (or energy detection threshold) for a preset strength of the received signal (hereinafter, the length of the channel detection section) of the second type By enabling it to be set to a value smaller than the average time or absolute time value of the channel detection section required in the channel access procedure, the probability that the unlicensed band is determined to be idle through the first type of channel access procedure, or The channel access possibility probability when the first type of channel access procedure is performed may be set to be greater than that when the second type of channel access procedure is performed. A more specific example is described below. The first type of channel access procedure performs the channel access procedure for X time defined in advance or set by the base station, and the second type of channel access procedure is Y time (Y>X) longer than the time X applied in the first type It can be set to perform the channel access procedure during the In this case, at least one of X and Y may be a predefined time or a fixed time interval as a time set by the base station or a time calculated according to the type of data to be transmitted. In addition, at least one of X and Y is a predefined time or a time set from the base station or a time calculated according to the type of data to be transmitted. In addition to a fixed time interval, a variable time interval, for example, within one interval It may be a time interval that varies according to an arbitrarily selected value. In this case, the time sections represented by X and Y can also be interpreted as meaning different channel access procedures or different channel access methods, respectively. Through this, by setting the length of the channel sensing section required when the first type of channel access procedure is performed is smaller than the length of the channel sensing section required when the second type of channel access procedure is performed, When the first type of channel access procedure is performed, the channel access possibility probability of the unlicensed band may be set to be greater than when the second type of channel access procedure is performed.

For another example, in performing the first type of channel access procedure, the channel sensing method required for determining the idle state of the unlicensed band is set differently from the channel sensing method required for the second type of channel access procedure, The probability of determining that the unlicensed band is in an idle state through the first type of channel access procedure, or the probability of channel access when the first type of channel access procedure is performed, when the second type of channel access procedure is performed It can be set to be larger. A more specific example is described below. The first type of channel access procedure is set to perform the above-mentioned channel detection operation for a fixed time period, and the second type of channel access procedure performs the channel detection operation for the unlicensed band for a variable time period arbitrarily selected in addition to the fixed period. By performing additionally, the length of the channel sensing section required when the first type of channel access procedure is performed is smaller than the length of the channel sensing section required when the second type of channel access procedure is performed. can be set to In this case, the terminal may receive a channel detection method that the terminal should use when transmitting an uplink signal from the base station through a downlink control channel including a group common downlink control channel or uplink scheduling information (or UL grant).

At this time, even in the case of a terminal configured with a grant-based uplink transmission scheme from a base station, if the unlicensed band in which the terminal performs uplink transmission and a downlink control channel through which the base station transmits uplink transmission configuration information are transmitted When the bands used are different (for example, when uplink transmission configuration information is received through a downlink control channel transmitted from a base station or cell of a licensed band, and the configured uplink transmission is configured in an unlicensed band), the grant- The second type of channel access procedure may be used even in the case of a terminal configured with a based uplink transmission scheme.

In addition, in the first type of channel access procedure or the second type of channel access procedure, a channel access procedure used by the base station for downlink channel access (hereinafter referred to as a third type channel access procedure) and at least one or more channel access procedures are set Variables required for can be set the same or different. In addition, the first, second, and third types of channel access procedures are the types of channels to be transmitted through the unlicensed band, for example, a channel access procedure for transmitting control information and a channel access procedure for transmitting data information. may be set differently depending on In addition, the first, second, and third types of channel access procedures are performed according to the type of channel to be transmitted through the unlicensed band, as well as the length of the unlicensed band occupancy time to be used after performing the channel access procedure. Variables of the first, second, and third types of channel access procedures may be set differently. In the embodiment of the present invention, it has been described that different channel access procedures are used according to the uplink signal transmission method of the terminal set by the base station. At least one variable among the first, second, and third types of channel access procedures may be set to be the same or different according to a length of time to be used.

A method of setting a channel access procedure according to the method of transmitting an uplink signal of a base station proposed by the present invention with reference to FIG. 3F is described as follows. In step 3f-601, the base station provides the terminal with an uplink transmission method (eg, grant-based) used for uplink transmission of the base station or cell through at least one method of an upper signal, a broadcast channel, or a downlink control channel. uplink transmission, a grant-free uplink transmission method, or a grant-based and grant-free uplink transmission method) may be configured. In step 3f-602, a variable necessary for uplink transmission may be additionally set according to the uplink transmission method set in step 3f-601. For example, the base station transmits configuration information for at least one resource region among a time resource region and a frequency resource region in which the configured grant-free uplink transmission can be performed to a terminal configured with a grant-free uplink transmission method. , may be transmitted or set to the terminal through at least one method of a broadcast channel or a downlink control channel. In this case, the step 3f-602 may be included in 3f-601 and may be configured or transmitted to the terminal. In step 3f-602, in addition to the time and frequency resource domain, MCS, information (cyclic shift), TTI length, or candidate values that the UE can select for the above variable values that the UE can use for grant-free uplink transmission, etc. Some or all of the variables required for uplink transmission configuration, including , may be set. At this time, if the uplink transmission configuration is the uplink transmission configuration for the unlicensed band, the base station changes the parameters related to the uplink channel access procedure differently in step 3f-602 according to the uplink transmission method set in step 3f-601. can be set. If the uplink transmission method set to the terminal in 3f-601 determined in step 3f-603 is a grant-based method, the base station in step 3f-604 except for the uplink transmission method set in step 3f-602 A variable necessary for link transmission is set, or a variable necessary for the remaining uplink transmission including at least one of the uplink transmission setting set in step 3f-602 is set, or a variable preset in step 3f-602 is set. When at least one variable among the values is set as a new variable value, the changed uplink configuration information is transmitted to the terminal through a downlink control channel, and the uplink transmission of the terminal according to the uplink transmission configured to the terminal can receive If the uplink transmission method set for the terminal in 3f-601 determined in step 3f-603 is a grant-free method, the base station sets for the grant-free uplink transmission method in step 3f-602 in step 3f-606. According to the setting value, it is possible to check whether the uplink transmission of the terminal is performed. If, in a base station or cell in which a grant-free uplink transmission method is set to a terminal through an upper signal or a broadcast channel, etc., the uplink transmission method for the terminal at a specific uplink transmission time is temporarily changed in a grant-based method. When changing, the base station includes some or all of the uplink transmission scheme set in step 3f-602 in step 3f-607, or transmits uplink configuration information set as a new variable value to the terminal through a downlink control channel and may receive the uplink transmission of the terminal according to the uplink transmission configured for the terminal.

A method for setting a channel access procedure according to a method for transmitting an uplink signal of a terminal proposed by the present invention will be described with reference to FIG. 3G. In step 3g-701, the terminal uses an uplink transmission method (eg, grant-based) used for uplink transmission from the base station to the base station or cell through at least one of an upper signal, a broadcast channel, or a downlink control channel. uplink transmission, a grant-free uplink transmission method, or a grant-based and grant-free uplink transmission method) may be configured. In step 3g-702, the UE may additionally set variable values required for uplink transmission from the base station according to the uplink transmission method set in step 3g-701. For example, the terminal in which the grant-free uplink transmission method is configured transmits configuration information for at least one of a time resource domain and a frequency resource domain in which the configured grant-free uplink transmission can be performed from the base station to an upper level signal. , a broadcast channel or a downlink control channel may be received or configured through at least one method. In this case, step 3g-702 may be included in 3g-701 and may be set by the base station. In this case, in step 3g-702, the terminal selects not only the time and frequency resource domain, but also the MCS, information (cyclic shift), TTI length, or the variable values that the terminal can use for grant-free uplink transmission. Some or all of the variables necessary for uplink transmission configuration, including possible candidate values, may be set. At this time, if the uplink transmission configuration determined through at least one of step 3g-701 or step 3g-702 is the uplink transmission configuration for the unlicensed band, the terminal receives the uplink channel from the base station in step 3g-702 Receives setting variables related to the access procedure. In this case, according to the uplink transmission method set in step 3g-701, at least one variable among the variables related to the uplink channel access procedure set in step 3g-702 may be set differently. If the uplink transmission scheme set by the base station in 3g-701 determined in step 3g-703 is a grant-based scheme, the UE excludes the uplink transmission scheme set in step 3g-702 in step 3g-704 to uplink Uplink in which all or part or all of the uplink transmission scheme set in step 3f-602 is received, or at least one variable value among the variable values received in step 3f-602 is set as a new variable value The configuration information is received through the downlink control channel of the base station, the terminal performs an uplink channel access procedure according to the uplink transmission received from the base station, and according to the result of the uplink channel access procedure for the unlicensed band, the Uplink transmission The uplink transmission operation may be performed according to the uplink transmission set in step 3g-704.

If the uplink transmission scheme configured by the base station in 3g-701 determined in step 3g-703 is a grant-free scheme, the terminal receives the grant-free uplink transmission scheme in steps 3g-702 from the base station in steps 3g-706 to 3g-702. A channel access procedure for the unlicensed band is performed according to the established channel access procedure, and an uplink transmission operation is transmitted according to the uplink transmission setting set in step 3g-702 according to the result of the uplink channel access procedure for the unlicensed band. can do. If, in a terminal configured with a grant-free uplink transmission scheme from a base station through an upper signal or a broadcast channel, etc., in step 3g-705, if the uplink transmission is preset with the grant-free configuration through the downlink control channel of the base station When receiving the uplink transmission configuration for , the terminal may perform uplink transmission according to the uplink channel access procedure and uplink transmission configuration newly received from the downlink control channel of the base station in step 3g-707. . In this case, the uplink channel access procedure of the terminal follows the method set in step 3g-702, and only uplink transmission configuration information may be transmitted according to the uplink transmission configuration newly received in step 3g-707.

In order to carry out the above embodiments, the terminal and the base station may each include a transmitter, a receiver, and a processor, respectively. The above embodiment shows a method for transmitting and receiving a base station and a terminal to determine transmission/reception timing of the second signal and perform an operation according thereto, and the transmitting unit, the receiving unit, and the processing unit may perform the above operation. In an embodiment, the transmitter and the receiver may be referred to as a transceiver capable of performing both functions, and the processor may be referred to as a controller.

3H is a block diagram illustrating the structure of a terminal according to an embodiment.

Referring to FIG. 3H, the terminal of the present invention may include a terminal receiving unit 3h-800, a terminal transmitting unit 3h-804, and a terminal processing unit 3h-802. The terminal receiving unit 3h-800 and the terminal collectively refer to the transmitting unit 3h-804, and may be referred to as a transceiver in the embodiment. The transceiver may transmit/receive a signal to/from the base station. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the strength of a signal received through the transceiver wireless channel is measured and output to the terminal processing unit 3h-802, and the terminal processing unit 3h-802 compares the received signal strength with a preset threshold value to access the channel operation, and a signal output from the terminal processing unit 3h-802 may be transmitted through a wireless channel according to a result of the channel access operation. In addition, the transceiver may receive a signal through a wireless channel, output it to the terminal processing unit 3h-802, and transmit a signal output from the terminal processing unit 3h-802 through a wireless channel. The terminal processing unit 3h-802 may control a series of processes so that the terminal can operate according to the above-described embodiment. For example, the terminal receiving unit 3h-800 may receive a signal including the second signal transmission timing information from the base station, and the terminal processing unit 3h-802 may control to interpret the second signal transmission timing. Thereafter, the terminal transmitter 3h-804 may transmit the second signal at the above timing.

3I is a block diagram illustrating a structure of a base station according to an embodiment.

Referring to FIG. 3I , in an embodiment, the base station may include at least one of a base station receiving unit 3i -901 , a base station transmitting unit 3i -905 , and a base station processing unit 3i-903 . The base station receiving unit 3i-901 and the base station transmitting unit 3i-905 may be collectively referred to as a transceiver in the embodiment of the present invention. The transceiver may transmit/receive a signal to/from the terminal. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel, output it to the base station processing unit 3i-903, and transmit the signal output from the terminal processing unit 3i-903 through the wireless channel. The base station processing unit 3i-903 may control a series of processes so that the base station can operate according to the above-described embodiment of the present invention. For example, the base station processing unit 3i-903 may determine the second signal transmission timing and control to generate the second signal transmission timing information to be transmitted to the terminal. Thereafter, the base station transmitter 3i-905 may transmit the timing information to the terminal, and the base station receiver 3i-901 may receive the second signal at the timing. For another example, the base station processing unit 3i-903 sets the uplink transmission method of the terminal so that at least one transmission method of a grant-free or a grant-based method can be used, and according to the set uplink transmission method The base station transmitter 3i-905 may transmit configuration information regarding uplink transmission including the defined uplink channel access procedure to the terminal.

Also, according to an embodiment of the present invention, the base station processing unit 3i-903 may control to generate downlink control information (DCI) including the second signal transmission timing information. In this case, the DCI may indicate the second signal transmission timing information.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are merely presented as specific examples to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. That is, it will be apparent to those of ordinary skill in the art to which the present invention pertains that other modified examples can be implemented based on the technical spirit of the present invention. In addition, each of the above embodiments may be operated in combination with each other as needed. For example, the base station and the terminal may be operated by combining parts of the embodiments of the present invention. In addition, although the above embodiments have been presented based on the NR system, other modified examples based on the technical idea of the embodiment may be implemented in other systems such as FDD or TDD LTE systems.

In addition, the present specification and drawings have been disclosed with respect to preferred embodiments of the present invention, and although specific terms are used, these are only used in a general sense to easily explain the technical content of the present invention and help the understanding of the present invention, It is not intended to limit the scope of the invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

Claims (15)

In a base station method in a wireless communication system,
transmitting configuration information for setting the terminal to a short transmission time interval (STTI);
transmitting, to the terminal, indication information indicating a position of a symbol in which an uplink reference signal related to the STTIs according to the configuration is transmitted; and
Receiving an uplink signal in the STTIs based on the indication information,
Based on the configuration information, one subframe is divided into 6 STTIs,
The six STTIs are, in order, 3, 2, 2, 2, 2 and 3 symbols, respectively, the base station method characterized in that it includes. According to claim 1,
The instruction information is
A base station method, characterized in that in at least one STTI, any one of a plurality of preset symbol patterns is indicated in relation to a position where the uplink reference signal can be transmitted. According to claim 1,
The indication information is bit information included in control information for scheduling uplink transmission of the terminal. According to claim 1,
In a specific STTI, the method further comprises decoding data included in the uplink signal using the uplink reference signal,
The uplink reference signal is transmitted in a symbol included in the specific STTI or a symbol included in the STTI that is continuous with the specific STTI and located before the specific STTI. A method of a terminal in a wireless communication system, comprising:
Transmitting, from the base station, configuration information for setting a short transmission time interval (STTI);
receiving, from the base station, indication information indicating a position of a symbol in which an uplink reference signal related to STTIs according to the configuration is transmitted; and
Transmitting an uplink signal to the base station in the STTIs based on the indication information,
Based on the configuration information, one subframe is divided into 6 STTIs,
The six STTIs are, in order, 3, 2, 2, 2, 2 and 3 symbols, respectively, the terminal method characterized in that it includes. 6. The method of claim 5,
The instruction information is
A terminal method, characterized in that in at least one STTI, any one of a plurality of preset symbol patterns is indicated in relation to a position where the uplink reference signal can be transmitted. 6. The method of claim 5,
The indication information is bit information included in control information for scheduling uplink transmission of the terminal. 6. The method of claim 5,
Based on the indication information, further comprising the step of determining a transmission position of the uplink reference signal for decoding the data included in the uplink signal,
The transmission position of the uplink reference signal includes a symbol included in a specific STTI or a symbol included in an STTI that is continuous with the specific STTI and located before the specific STTI. In a base station in a wireless communication system,
transceiver; and
Controls the transceiver to transmit configuration information for setting the terminal to a short transmission time interval (STTI), and indicates the position of a symbol in which an uplink reference signal related to STTIs according to the configuration is transmitted A control unit for controlling the transceiver to transmit indication information to the terminal, and a control unit for controlling the transceiver to receive an uplink signal in the STTIs based on the indication information,
Based on the configuration information, one subframe is divided into 6 STTIs,
The six STTIs are, in order, 3, 2, 2, 2, 2 and 3 symbols, respectively, the base station comprising: 10. The method of claim 9,
The instruction information is
A base station, characterized in that in at least one STTI, any one of a plurality of preset symbol patterns is indicated in relation to a position where the uplink reference signal can be transmitted. 10. The method of claim 9,
The indication information is bit information included in control information for scheduling uplink transmission of the terminal. 10. The method of claim 9,
The controller decodes data included in the uplink signal using the uplink reference signal in a specific STTI,
A base station, characterized in that the transmission is performed in a symbol included in the specific STTI, or a symbol included in the STTI that is continuous with the specific STTI and located before the specific STTI. In a terminal in a wireless communication system,
transceiver; and
The base station controls the transceiver to transmit configuration information for setting a short transmission time interval (STTI), and from the base station, an uplink reference signal related to STTIs according to the configuration is transmitted. a control unit for controlling the transceiver to receive indication information indicating the location of
Based on the configuration information, one subframe is divided into 6 STTIs,
The six STTIs are, in order, 3, 2, 2, 2, 2 and 3 terminals, characterized in that each includes symbols. 14. The method of claim 13,
The instruction information is
A bit that is included in control information for scheduling uplink transmission of the terminal and is transmitted, and in at least one STTI, a bit indicating any one of a plurality of preset symbol patterns in relation to a position where the uplink reference signal can be transmitted A terminal, characterized in that the information. 14. The method of claim 13,
The controller determines, based on the indication information, a transmission position of the uplink reference signal for decoding data included in the uplink signal,
The transmission position of the uplink reference signal includes a symbol included in a specific STTI or a symbol included in an STTI that is continuous with the specific STTI and located before the specific STTI.

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