KR102362708B1 - Method for repetition transmission by using frequency hopping for ultra-reliable and low latency communication in a wireless communication system and apparatus thereof - Google Patents

Abstract

Provided are a repeated transmission method using frequency hopping for ultra-low-latency, high-reliability communication in a wireless communication system, and an apparatus therefor. A method for a terminal to transmit data in a wireless communication system includes the steps of: receiving downlink control information including information on the number of repeated transmissions of uplink data and information on frequency hopping from a base station, the repetition constructing a plurality of physical uplink shared channels (PUSCHs) corresponding to the number of transmissions, wherein the uplink data are equally mapped to the plurality of PUSCHs, and based on the information on the frequency hopping, of the plurality of PUSCHs Determining a frequency resource for transmission, wherein the range of frequency hopping may be changed according to the size of a bandwidth part activated for transmission of the uplink data.

Description

Repetitive transmission method using frequency hopping for ultra-low-latency, high-reliability communication in a wireless communication system, and an apparatus therefor

The present invention relates to a method and apparatus for repeatedly transmitting data in a wireless communication system, and more particularly, to a method and apparatus for repeatedly transmitting the same data using frequency hopping for ultra-low latency and high reliability communication.

For communication in various application fields corresponding to the 5G URLLC (Ultra-Reliable and Low Latency Communication) communication scenario, data needs to be transmitted quickly and stably. However, when the terminal moves in a direction in which the channel deteriorates in an environment in which the terminal moves rapidly, an error may occur when the base station sets and transmits the transmission format based on the CQI (channel quality indicator) fed back to the base station by the corresponding terminal. , this may cause a situation in which the data needs to be retransmitted.

In the case of general data transmission, there is no problem even if data is retransmitted. However, in the case of transmitting URLLC data, if retransmission occurs, a problem of increasing latency may occur.

An object of the present invention is to provide a method for stably and repeatedly transmitting data with a short delay using frequency hopping.

An object of the present invention is to provide an apparatus for stably transmitting data using frequency hopping with a short delay.

According to an aspect of the present invention, in a method for a terminal to transmit data in a wireless communication system, downlink control information including information about the number of repeated transmissions of uplink data from a base station and information about frequency hopping ), configuring a plurality of physical uplink shared channels (PUSCHs) corresponding to the number of repeated transmissions, wherein the uplink data are equally mapped to the plurality of PUSCHs, and information on the frequency hopping Determining a frequency resource for transmission of the plurality of PUSCHs based on have.

According to one side, the downlink control information further includes information on the length of a mini-slot used for repeated transmission of the uplink data, and the plurality of PUSCHs are transmitted in units of the mini-slot. can

According to another aspect, the frequency resource may be a frequency resource corresponding to both ends of the activated bandwidth portion.

According to another aspect, the method may further include transmitting channel quality information to the base station before the receiving step, wherein the information on the frequency hopping may be determined based on the channel quality information.

According to another aspect, the information on the frequency hopping may include information on whether to apply the frequency hopping and information on the frequency hopping pattern.

According to another aspect, the method further includes receiving information on a default number of repeated transmissions for uplink transmission from the base station before the receiving step, wherein the downlink control information includes the basic number of repeated transmissions. and information on a difference value between the actual number of repeated transmissions of the uplink data.

According to another aspect of the present invention, a method for a base station to receive data in a wireless communication system includes determining whether to apply frequency hopping to uplink data of the terminal based on channel quality information received from the terminal; Transmitting downlink control information including information on the number of repeated transmissions of the uplink data and information on the frequency hopping to the terminal, and the repetition through a frequency resource determined based on the information on the frequency hopping Receiving a plurality of PUSCHs corresponding to the number of transmissions from the terminal, wherein the uplink data is equally mapped to the plurality of PUSCHs, and the range of the frequency hopping is determined by the terminal for the transmission of the uplink data It may be changed according to the size of the active bandwidth portion.

According to the present invention, when data corresponds to URLLC (ultra-reliable low latency communication), the transmitter can transmit the same data twice or more using frequency hopping based on mini-slot, so that data is transmitted more quickly and stably. can be transmitted

1 is a conceptual diagram illustrating a wireless communication system according to an embodiment of the present invention.
2 is an exemplary diagram illustrating an NR system to which a data transmission method according to an embodiment of the present invention can be applied.
3 is a diagram illustrating a slot structure used in a data transmission method according to an embodiment of the present invention.
4 is a diagram for explaining a mini-slot used in a data transmission method according to an embodiment of the present invention.
5 is a diagram illustrating an example of a frequency allocation scheme and BWP to which the technical features of the present invention can be applied.
6 is a diagram illustrating an example of a bandwidth adaptation scheme for transmitting multiple BWPs and BWPs to which the technical features of the present invention can be applied while changing.
7 to 13 are flowcharts illustrating a frequency hopping method according to an embodiment of the present invention.
14 is a flowchart illustrating a data transmission method according to an embodiment of the present invention.
15 is a block diagram illustrating a wireless communication system in which an embodiment of the present invention is implemented.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements.

In this specification, terms such as “first”, “second”, “A”, and “B” may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. The term “and/or” also includes combinations of a plurality of related listed items or any of a plurality of related listed items.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terminology used herein is used only to describe specific embodiments, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that a feature, number, step, operation, component, part, or a combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, terms used herein have the same meanings as commonly understood by those of ordinary skill in the art to which the present invention belongs, including technical or scientific terms. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present specification. does not

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

1 is a conceptual diagram illustrating a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 1 , a wireless communication system 100 includes a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3. , 130-4, 130-5, 130-6).

Each of the plurality of communication nodes may support at least one communication protocol. For example, each of the plurality of communication nodes is a CDMA (Code Division Multiple Access) based communication protocol, WCDMA (Wideband CDMA) based communication protocol, TDMA (Time Division Multiple Access) based communication protocol, FDMA (Frequency Division Multiple) Access) based communication protocol, OFDM (Orthogonal Frequency Division Multiplexing) based communication protocol, OFDMA (Orthogonal Frequency Division Multiple Access) based communication protocol, SC (Single Carrier)-FDMA based communication protocol, NOMA (Non-Orthogonal Multiplexing) Access)-based communication protocol, space division multiple access (SDMA)-based communication protocol, etc. may be supported.

The wireless communication system 100 includes a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 and a plurality of user equipments 130-1, 130-2, 130-3, 130-4, 130-5, 130-6).

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the coverage of the third base station 110-3. . The first terminal 130-1 may belong to the coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the coverage of the fifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 is a NodeB, an evolved NodeB, and a next generation Node B (NodeB). B, gNB), BTS (Base Transceiver Station), radio base station (radio base station), radio transceiver (radio transceiver), access point (access point), access node (node), roadside unit (road side unit, RSU), DU (Digital Unit), CDU (Cloud Digital Unit), RRH (Radio Remote Head), RU (Radio Unit), TP (Transmission Point), TRP (transmission and reception point), to be referred to as a relay node (relay node), etc. can Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 is a terminal, an access terminal, a mobile terminal, It may be referred to as a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, and the like.

A plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) Each may support cellular communication (eg, long term evolution (LTE), advanced (LTE-A), new radio (NR), etc. defined in the ^3rd generation partnership project (3GPP) standard). Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other through an ideal backhaul or a non-ideal backhaul, and the ideal backhaul Alternatively, information may be exchanged with each other through a non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to a core network (not shown) through an ideal backhaul or a non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to the corresponding terminals 130-1, 130-2, 130-3, 130 -4, 130-5, 130-6), and the signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) is transmitted to the core network can be sent to

Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may support OFDMA-based downlink transmission, and OFDMA or SC-FDMA-based uplink (uplink) transmission may be supported. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 is MIMO (Multiple Input Multiple Output) transmission (eg, SU (Single User)-MIMO, MU (Multi User)-MIMO, massive MIMO, etc.), Coordinated Multipoint (CoMP) transmission, carrier aggregation transmission, transmission in an unlicensed band, direct device to device, D2D) communication (or Proximity services (ProSe)) may be supported, etc. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 Base stations 110-1, 110-2, 110-3, 120-1, 120-2 and corresponding operations and/or base stations 110-1, 110-2, 110-3, 120-1, 120-2 ) can perform operations supported by

For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 based on the SU-MIMO method, and the fourth terminal 130-4 may transmit a signal based on the SU-MIMO method. A signal may be received from the second base station 110 - 2 . Alternatively, the second base station 110 - 2 may transmit a signal to the fourth terminal 130 - 4 and the fifth terminal 130 - 5 based on the MU-MIMO scheme, and the fourth terminal 130 - 4 . and each of the fifth terminals 130 - 5 may receive a signal from the second base station 110 - 2 by the MU-MIMO method. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, and the fourth The terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by the CoMP method. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 includes the terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) and a signal may be transmitted/received based on the CA method.

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 coordinates D2D communication between the fourth terminal 130-4 and the fifth terminal 130-5. (coordination), each of the fourth terminal 130-4 and the fifth terminal 130-5 is D2D communication by the coordination of each of the second base station 110-2 and the third base station 110-3 can be performed.

Hereinafter, even when a method (eg, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a second communication node corresponding thereto corresponds to the method performed in the first communication node A method (eg, receiving or transmitting a signal) may be performed. That is, when the operation of the terminal is described, the corresponding base station may perform the operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the corresponding terminal may perform the operation corresponding to the operation of the base station.

Also, hereinafter, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In the downlink, the transmitter may be a part of the base station, and the receiver may be a part of the terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of the base station.

Recently, as the spread of smartphones and Internet of Things (IoT) terminals is rapidly spreading, the amount of information exchanged through a communication network is increasing. Accordingly, in the next-generation wireless access technology, an environment (eg, enhanced mobile broadband communication) that provides a faster service to more users than the existing communication system (or the existing radio access technology) )) needs to be considered. To this end, design of a communication system in consideration of MTC (Machine Type Communication) providing a service by connecting a plurality of devices and objects is being discussed. In addition, the design of a communication system (eg, URLLC (Ultra-Reliable and Low Latency Communication) that considers a service and/or terminal sensitive to communication reliability and/or latency) is being discussed

Hereinafter, in this specification, for convenience of description, the next-generation radio access technology is referred to as a New Radio Access Technology (RAT), and a wireless communication system to which the New RAT is applied is referred to as a New Radio (NR) system.

2 is an exemplary diagram illustrating an NR system to which a data transmission method according to an embodiment of the present invention can be applied.

Referring to Figure 2, NG-RAN (Next Generation-Radio Access Network) is a control plane (RRC) protocol for the NG-RA user plane (new AS sublayer/PDCP/RLC/MAC/PHY) and UE (User Equipment) It consists of gNBs that provide termination. The NG-RAN may also include an existing LTE base station, an eNB. Here, NG-C represents a control plane interface used for the NG2 reference point between the NG-RAN and the 5GC (5 Generation Core). NG-U represents the user plane interface used for the NG3 reference point between NG-RAN and 5GC.

The gNBs are interconnected through the Xn interface and connected to the 5GC through the NG interface. More specifically, the gNB is connected to an Access and Mobility Management Function (AMF) through the NG-C interface and to a User Plane Function (UPF) through the NG-U interface.

In the NR system of FIG. 2, multiple numerologies may be supported. Here, the numerology may be defined by a subcarrier spacing (SCS) and a cyclic prefix (CP) overhead. In this case, the plurality of subcarrier intervals may be derived by scaling the basic subcarrier interval by an integer. Also, although it is assumed that very low subcarrier spacing is not used at very high carrier frequencies, the numerology used can be selected independently of the frequency band.

In addition, in the NR system, various frame structures according to a number of numerologies may be supported. Hereinafter, OFDM numerology and a frame structure used in a data transmission method according to an embodiment of the present invention will be described with reference to FIG. 3 .

3 is a diagram illustrating a slot structure used in a data transmission method according to an embodiment of the present invention.

A time division duplexing (TDD) structure considered in the NR system is a structure in which both uplink (UL) and downlink (DL) are processed in one slot (or subframe). This is to minimize the latency of data transmission in the TDD system, and may be referred to as a self-contained structure or a self-contained slot.

Referring to FIG. 3 , one slot may consist of 14 OFDM symbols. When an extended cyclic prefix (CP) is used, one slot may consist of 12 OFDM symbols. In FIG. 3, region 310 indicates a downlink control region, and region 320 indicates an uplink control region. The number of symbols used in the downlink control region 310 and the uplink control region 320 may be one or more. Regions other than the downlink control region 310 and the uplink control region 320 (ie, a region without a separate indication) may be used for transmission of downlink data or uplink data. Accordingly, the uplink control information and the downlink control information may be transmitted in one slot. In the case of data, uplink data and/or downlink data may be transmitted in one slot.

When the structure shown in FIG. 3 is used, downlink transmission and uplink transmission are sequentially performed within one slot, and transmission of downlink data and reception of uplink ACK/NACK may be performed. Accordingly, when an error in data transmission occurs, the time required for data retransmission can be reduced. In this way, the delay associated with data transmission can be minimized.

In the slot structure as shown in FIG. 3, a time gap is required for a process in which a base station and/or a terminal converts from a transmission mode to a reception mode or a process from a reception mode to a transmission mode. do. In relation to the time difference, when uplink transmission is performed after downlink transmission in the slot, some OFDM symbol(s) may be set as a guard period (GP).

4 is a diagram for explaining a mini-slot used in a data transmission method according to an embodiment of the present invention.

According to an embodiment of the present invention, in addition to the slot-based scheduling for efficient support of URLLC, mini-slot-based scheduling may be supported. Hereinafter, a transmission scheme based on a mini-slot is also referred to as a non-slot transmission scheme. The mini-slot is a minimum scheduling unit by the base station, and may be transmitted in units smaller than the slot (1 to 13 symbols). For example, a mini-slot may consist of 2, 4, or 7 OFDM symbols.

A mini-slot may be started in any OFDM symbol in the slot as shown in FIG. In FIG. 4 , two mini-slots having different lengths (the number of OFDM symbols) are shown in one slot, but this is for illustrative purposes only. When a plurality of mini-slots are included in one slot, each mini-slot is The number of OFDM symbols constituting ? may be the same.

Hereinafter, resource allocation in the NR system will be described.

In the NR system, a specific number (eg, a maximum of 4 for each downlink and uplink) of a bandwidth part (BWP) may be defined. BWP (or carrier BWP) is a set of continuous PRBs (Physical Resource Blocks), and may be represented as a continuous subset of common RBs (CRBs). Each RB in the CRB may start with CRB0 and may be represented by CRB1, CRB2, and the like.

5 is a diagram illustrating an example of a frequency allocation scheme and BWPs to which the technical features of the present invention can be applied.

Referring to FIG. 5 , a plurality of BWPs may be defined in a CRB grid. The reference point of the CRB grid (which may be referred to as a common reference point, starting point, etc.) is called "point A" in NR. Point A is indicated by Remaining Minimum System Information (RMSI). Specifically, the frequency offset between the point A and the frequency band in which the Synchronization Signal (SS)/Physical Broadcast Channel (PBCH) block is transmitted may be indicated through the System Information Block #1 (SIB1) of the RMSI. Point A corresponds to the first subcarrier of CRB0. Also, point A may be a point at which a variable “k” indicating a frequency band of RE in NR is set to zero. A plurality of BWPs illustrated in FIG. 5 are configured of one cell (eg, a primary cell (PCell)). A plurality of BWPs may be configured for each cell individually or in common.

Referring to FIG. 5 , each BWP may be defined by a size and a starting point from CRB0. For example, the first BWP, that is, BWP #0, may be defined by a starting point through an offset from CRB0, and the size of BWP#1 may be determined through a size for BWP#0. Each BWP may be defined to overlap within the entire channel bandwidth (CBW: Channel BandWidth).

A specific number of BWPs (eg, up to 4 each in downlink and uplink) may be configured for the terminal. In the 3GPP Release 15 standard, even if a plurality of BWPs are configured, only a specific number (eg, one) of BWPs can be activated for each cell during a given time. However, in a later standard, it may be changed so that a plurality of BWPs can be activated for a given time. However, when a supplementary uplink (SUL) carrier is configured in the UE, up to four BWPs may be additionally configured in the SUL carrier, and one BWP may be activated for a given time. The number of configurable BWPs or the number of activated BWPs may be commonly or individually configured for UL and DL. In addition, the numerology and/or CP for the DL BWP and the numerology and/or CP for the UL BWP may be configured in the terminal through DL signaling. The UE may receive PDSCH, PDCCH, CSI (channel state information) RS and or TRS (tracking RS) only in active DL BWP. In addition, the UE may transmit a PUSCH and/or a physical uplink control channel (PUCCH) only to the active UL BWP.

6 is a diagram illustrating an example of Bandwidth Adaptation in which multiple BWPs to which the technical features of the present invention can be applied are temporally changed.

6 is an assumption that three BWPs are set. The first BWP may span a 40 MHz band and a subcarrier spacing of 15 kHz may be applied. The second BWP may span a 10 MHz band and a subcarrier spacing of 15 kHz may be applied. The third BWP may span a 20 MHz band and a subcarrier spacing of 60 kHz may be applied. The terminal may configure at least one BWP among the three BWPs as an active BWP, and may perform UL and/or DL data communication through the active BWP.

The time resource may be indicated in a manner that indicates the time difference/offset based on the transmission time of the PDCCH to which the DL or UL resource is allocated. For example, the start point of the PDSCH/PUSCH corresponding to the PDCCH and the number of symbols occupied by the PDSCH/PUSCH may be indicated.

In the NR system, like LTE/LTE-A, carrier aggregation (CA) may be supported. That is, by aggregating contiguous or discontinuous component carriers (CCs), a bandwidth may be increased, and as a result, a bit rate may be increased. Each CC may correspond to a (serving) cell, and each CC/cell may be divided into a primary serving cell (PSC)/primary CC (PCC) or a secondary serving cell (SSC)/secondary CC (SCC).

In addition, single-beam and multi-beam forming can be supported in the NR system. The network may deploy a single beam or multiple beams. Different single beams may be used at different times. Regardless of whether a single beam or multiple beams are deployed, from a UE perspective, it may be necessary to indicate a resource to be monitored for control channel monitoring. In particular, when multiple beams are used or repetition is used, from the UE point of view, the same control channel may be transmitted multiple times.

For communication in various application fields corresponding to V2X (Vehicle to Everything) and URLLC scenarios in the NR system, it is necessary to transmit data stably and quickly with almost no errors. In particular, when the terminal moves in a direction in which the channel deteriorates in an environment in which the terminal moves rapidly, an error may occur when the terminal sets the transmission format and transmits data based on the CQI fed back to the base station by the terminal, and this may cause retransmission There is a high probability that you will have to In the case of transmitting general data such as eMBB (enhanced　mobile　Broad Band) data, there is no problem even if retransmission occurs. In most cases, such as V2X scenarios and URLLC scenarios, the amount of transmitted user data is not large, so using some additional resources may not be a big burden. Rather, it may be worse if an error occurs and the delay increases due to the retransmission. Therefore, in the present invention, the same data can be repeatedly transmitted or transmitted repeatedly in the following way. The data transmission method according to the present invention can be applied to various scenarios of URLLC as well as vehicle communication such as V2X.

7 to 13 are flowcharts illustrating a frequency hopping method according to an embodiment of the present invention.

According to the present embodiment, when the transmitter repeatedly or repeatedly transmits the same information (same data) to the receiver, frequency hopping (FH) may be performed in the frequency domain. Here, when the transmitter is a terminal, the receiver may be a base station or another terminal. When the transmitter is a base station, the receiver may be a terminal.

As an example, the terminal may perform frequency hopping in the frequency domain in units of mini-slots when repeatedly or overlapping the same data is transmitted to the base station. For example, after the UE configures a plurality of PUSCHs corresponding to the number of repeated transmissions, the first PUSCH is transmitted to the base station using a first frequency in the first mini-slot, and the second PUSCH is temporally synchronized with the first mini-slot. Transmission may be performed to the base station using a second frequency according to frequency hopping in a second adjacent mini-slot. Here, the same uplink data may be equally mapped to each PUSCH.

As another example, the base station may perform frequency hopping in the frequency domain in units of mini-slots when the same data is repeatedly or duplicated to be transmitted to the terminal. For example, after the base station configures a plurality of PDSCHs corresponding to the number of repeated transmissions, the first PDSCH is transmitted to the terminal using the first frequency in the first mini-slot, and the second PUSCH is temporally synchronized with the first mini-slot. It can be transmitted to the terminal using the second frequency in the second adjacent mini-slot. Here, the same downlink data may be equally mapped to each PDSCH.

This embodiment can be equally applied to a sidelink transmission environment. In this case, the transmitter may be a transmitting terminal, and the receiver may be a receiving terminal. Data transmitted through the sidelink may be referred to as PSSCH or PSSCH data, or data related to URLLC.

Also, in the present embodiment, the range of frequencies used for frequency hopping may vary according to the size of a bandwidth part (BWP). For example, the transmitter may use frequency resources corresponding to both ends of the BWP for the FH in order to maximize the effect of frequency diversity. For example, as shown in FIG. 7 , when the BWP is configured with 10 PRBs (PRB #0 to PRB #9) and 4 repeated transmissions are set, the transmitter is in the BWP in the first minislot and the third minislot. The same data may be transmitted using PRB #0, which is the lowest frequency resource, and the same data may be transmitted using PRB #9, which is the highest frequency resource in the BWP, in the second and fourth minislots. Alternatively, the transmitter transmits the same data using PRB #9 in the first minislot and the third minislot, and uses PRB #0 in the second and fourth minislots to transmit the same data, unlike in FIG. 7 . can also be sent.

Meanwhile, when more frequency resources (Resource Blocks: RBs) are required for data transmission, the transmitter may use multiple frequency resources while increasing the number of RBs from the end of the BWP. For example, in a situation where the BWP consists of 10 PRBs (PRB#0 to PRB#9) and 4 repeated transmissions are set as shown in FIG. 8, the transmitter transmits PRBs in the first minislot and the third minislot. The same data may be transmitted using #0 and PRB #1, and the same data may be transmitted using PRB #8 and PRB #9 in the second and fourth minislots. Alternatively, unlike FIG. 8, the transmitter transmits the same data using PRB #8 and PRB #9 in the first and third minislots, and PRB #0 and PRB #0 in the second and fourth minislots. The same data may be transmitted using PRB #1.

In addition, when there is a lot of URLLC traffic to which frequency hopping is applied, it is necessary to prevent collision of frequency resources. In particular, when resources to be used for frequency hopping overlap between multiple terminals, it is necessary to adjust the frequency hopping range so that the frequency resources do not collide. For this purpose, when frequency hopping is applied, the frequency resource at the end of the BWP may be basically used, but may be changed if necessary. For example, if four repeated transmissions are set for the first terminal and the second terminal and the frequency hopping resource of the first terminal and the frequency hopping resource of the second terminal overlap, as shown in FIG. 9 , the first terminal transmits the frequency The same data is repeatedly transmitted using frequency hopping in units of mini-slots based on PRB #0 and PRB #9, which are frequency resources that are basically set for hopping, and the second terminal basically adjusts the frequency hopping range within the BWP. The same data may be repeatedly transmitted using frequency hopping in mini-slot units based on PRB #1 and PRB #8, which are inner frequency resources of the configured frequency resource. Alternatively, as shown in FIG. 10, both the first terminal and the second terminal adjust the frequency hopping range so that the first terminal repeatedly transmits data using PRB #0 and PRB #8, and the second terminal repeatedly transmits the PRB #1 and PRB #9 can be used to repeatedly transmit data. Alternatively, as shown in FIG. 11 , the first terminal and the second terminal use the same frequency resource, but may repeatedly transmit the same data using different frequency hopping patterns.

Meanwhile, when repeatedly transmitting the same data, frequency hopping may not be performed within one mini slot in order to reduce complexity. When multiple mini-slots are used to repeatedly transmit the same data, frequency hopping may be applied. When overlapping or repeated transmission occurs over several slots, a frequency different from the frequency used in the previous slot may be used in the next slot. That is, inter-slot FH may be applied. In this case, for example, if the base station or the transmitting terminal can trust the channel information (channel gain for each frequency, etc.), frequency hopping is not applied, but a frequency resource having a good channel condition is allocated to repeatedly transmit data. can

Such frequency hopping-related information, for example, FH-related configuration information, may be configured by the base station semi-statically by using higher layer RRC (Radio Resource Control) signaling, and the like, and may be notified to the terminal. In addition, control information related to FH may be included in DCI and transmitted over PDCCH. In the case of a sidelink transmission environment, the FH-related information may be transmitted by the base station to the terminal through higher layer signaling such as RRC, or the transmitting terminal may transmit it to the receiving terminal. For example, the base station may inform the terminal of information on whether FH is applied, information on the FH pattern, and the like through DCI. That is, the base station can inform the terminal by including control information for transmitting and receiving data in this transmission method in the DCI. In this case, a new field may be added to the DCI. When the transmitting terminal repeatedly or redundantly transmits data to the receiving terminal, the transmitting terminal may inform the receiving terminal of information on whether FH is applied or not, information on the FH pattern, etc. to the receiving terminal through SCI (Sidelink Control Information).

In uplink transmission or downlink transmission, the length of the mini-slot and the number of repeated transmissions may be notified by the base station to the terminal through DCI. However, the number of repeated transmissions may be set by notifying the RRC in advance. As an example, the base station may notify the default number of repeated transmissions through RRC, and if it is necessary to change the basic number of repeated transmissions, the base station may inform the UE of the actual number of repeated transmissions through DCI. In this case, information on a difference value between the basic number of repeated transmissions and the actual number of repeated transmissions may be included in the DCI. In sidelink transmission, the length of the mini-slot and the number of repeated transmissions may be notified to the receiving terminal by the transmitting terminal or the base station through SCI or DCI.

Meanwhile, when frequency hopping is used, a separate DeModulation Reference Signal (DM-RS) may be applied to each repeated transmission. However, when the transmitter repeatedly transmits the same data to the receiver using the same frequency resource, the DM-RS may not be used separately. That is, repeated transmission may be performed several times with one DM-RS. However, when the channel is quickly changed, the DM-RS may be separately used even if the same frequency resource is used. That is, a separate DM-RS may be applied to each repeated transmission.

In addition, the number of DM-RS used during repeated transmission may be applied differently according to a service or QoS of the service. For example, in case of high-speed movement, DM-RS is separately applied for each repeated transmission, and in case of slow movement, one DM-RS may be repeatedly transmitted several times.

Meanwhile, in the case of very important information, the same information may be repeatedly transmitted in the frequency domain and the time domain. For example, the transmitter may transmit the same information to each frequency resource multiple times by allocating a plurality of frequency resources. For example, as shown in FIG. 12 , the transmitter may map the same data to PRB#0 and PRB#9, respectively, and transmit the same to the first to fourth minislots. This method may be more suitable in a mm-Wave environment with many frequency resources and short time resources.

As another example, the transmitter may transmit the same information multiple times using both different frequency and time resources. For example, as shown in FIG. 13 , the transmitter performs frequency hopping by using PRB#0 and PRB#9 when repeatedly transmitting the first data, and for the second data identical to the first data, the optimal frequency resource based on CQI Repeated transmission may be performed using (RPB #5 in FIG. 13).

In the above-described embodiment, the frequency hopping resource may be derived based on Table 1 below.

Referring to Table 1, a frequency hopping offset during repeated transmission may be determined based on the number of RPBs in the active uplink BWP. In addition, a frequency hopping pattern may be determined according to the value of the hopping bit. This frequency hopping resource determination method may be equally applied to downlink.

14 is a flowchart illustrating a data transmission method according to an embodiment of the present invention.

According to this embodiment, the transmitter may repeatedly transmit the same data to the receiver in various ways according to channel conditions. Here, the transmitter may be a base station or a transmitting terminal, and the receiver may be a base station or a receiving terminal.

Hereinafter, as an example, a case in which the terminal repeatedly transmits uplink data to the base station will be described with reference to FIG. 14 .

The base station may determine whether to apply frequency hopping to uplink data to be transmitted by the corresponding terminal based on the CQI report received from the terminal. To this end, the terminal may transmit a CQI report to the base station by checking the channel state (S1410). The base station checks the channel condition based on the CQI value included in the CQI report received from the terminal, and if the channel condition is good, it determines to repeatedly transmit the data without applying frequency hopping, and if the channel condition is not good, , when the channel information is unknown or unreliable, it may be decided to apply frequency hopping during repeated transmission. In addition, the base station may transmit DCI including information about the number of repeated transmissions of uplink data and information about frequency hopping to the corresponding terminal. Here, the DCI may further include information on the length of a mini-slot used for repetitive transmission, in addition to information on the number of repeated transmissions and information on frequency hopping. In addition, the information on the frequency hopping may include information on whether frequency hopping is applied and/or information on a frequency hopping pattern.

When the terminal receives the DCI from the base station, it may determine whether to perform frequency hopping based on the DCI (S1420). If it is determined to perform repeated transmission without applying frequency hopping, the UE may repeatedly transmit the same data using an optimal frequency resource (S1430). In this case, the terminal may repeatedly transmit the same data using a plurality of frequency and/or time resources according to the importance of the data.

However, if it is determined to apply frequency hopping during repeated transmission, the terminal transmits first data using the first frequency in the first mini-slot (S1440), and in the second mini-slot temporally adjacent to the first mini-slot The same data as the first data may be repeatedly transmitted to the receiver using the second frequency according to frequency hopping ( S1450 ). In this case, the terminal may repeatedly transmit the same data using at least one of the frequency hopping methods of FIGS. 7 to 13 .

For example, when DCI is received from the base station, the terminal configures a plurality of PUSCHs corresponding to the number of repeated transmissions based on information on the number of repeated transmissions included in the DCI, and information on frequency hopping included in the DCI A frequency resource for transmission of a plurality of PUSCHs may be determined based on . In this case, the uplink data may be equally mapped to the plurality of PUSCHs. In addition, the range of frequency hopping during repeated transmission may be changed according to the size of the BWP activated for transmission of the corresponding uplink data.

15 is a block diagram illustrating a wireless communication system in which an embodiment of the present invention is implemented.

Referring to FIG. 15 , the terminal 1500 includes a memory 1505 , a processor 1510 , and an RF unit (radio frequency (RF) unit, 1515 ). The memory 1505 is connected to the processor 1510 and stores various information for driving the processor 1510 . The RF unit 1515 is connected to the processor 1510 to transmit and/or receive a radio signal. For example, the RF unit 1515 may receive an RRC message, configuration and/or control information such as DCI, and a downlink signal such as a PDSCH, posted herein from the base station 1550 . Also, the RF unit 1515 may transmit an uplink signal such as a CQI report and a PUSCH published in this specification to the base station 1550 or may transmit/receive a PSSCH with another terminal (not shown).

The processor 1510 implements the terminal function, process and/or method proposed in this specification. Specifically, the processor 1510 performs the operation of the terminal according to FIGS. 7 to 14 . For example, the processor 1510 may configure a plurality of PUSCHs or a plurality of PSSCHs according to an embodiment of the present invention and transmit them using the frequency hopping method according to any one of FIGS. 7 to 13 . In all embodiments of the present specification, the operation of the terminal 1500 may be implemented by the processor 1510 .

The memory 1505 may store control information and setting information according to the present specification, and may provide the control information and setting information to the processor 1510 according to a request of the processor 1510 .

The base station 81550 includes a processor 1555 , a memory 1560 , and an RF unit (radio frequency (RF) unit, 1565 ). The memory 1560 is connected to the processor 1555 and stores various information for driving the processor 1555 . The RF unit 1565 is connected to the processor 1555 to transmit and/or receive a radio signal. The processor 1555 implements the functions, processes and/or methods of the base station proposed in this specification. In the above-described embodiment, the operation of the base station may be implemented by the processor 1555 . The processor 1555 may generate an RRC message, downlink control information, etc. posted herein, or configure a plurality of PDSCHs.

The processor may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and/or data processing devices. Memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The RF unit may include a baseband circuit for processing a radio signal. When the embodiment of the present invention is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) that performs the above-described function. The module may be stored in a memory and executed by a processor. The memory may be internal or external to the processor, and may be coupled to the processor by various well-known means.

In the exemplary system described above, the methods are described on the basis of a flowchart as a series of steps or blocks, but the present invention is not limited to the order of steps, and some steps may occur in a different order or concurrently with other steps as described above. can In addition, those skilled in the art will understand that the steps shown in the flowchart are not exhaustive and that other steps may be included or that one or more steps in the flowchart may be deleted without affecting the scope of the present invention.

Claims (18)

In a method for a terminal to transmit data in a wireless communication system,
Receiving configuration information for adjusting a range of frequency hopping from a base station;
Receiving information on the number of repeated transmission of uplink data from the base station;
Receiving downlink control information including control information on frequency hopping from the base station;
configuring a physical uplink shared channel (PUSCH) repetition corresponding to the number of repeated transmissions; and
Including the step of performing frequency hopping in the order of PUSCH repetition,
The performing of the frequency hopping includes using a plurality of RBs including a first basic resource block (RB) that is basically configured for a first PUSCH repetition, and a location spaced apart from the first basic RB for a second PUSCH repetition using a plurality of RBs including a second basic RB of
The predetermined interval between the first basic RB and the second basic RB is characterized in that it is determined based on the size of a bandwidth part (BWP) activated for transmission of the uplink data. . According to claim 1,
The downlink control information,
Further comprising information on the length of a mini-slot used for repeated transmission of the uplink data,
The PUSCH repetition is
The data transmission method, characterized in that performed in units of the mini-slot. According to claim 1,
The plurality of RBs including the first RB and the plurality of RBs including the second RB are frequency resources corresponding to both ends of the activated bandwidth portion, respectively. According to claim 1,
Further comprising the step of transmitting channel quality information (channel quality information) to the base station,
The control information regarding the frequency hopping,
Data transmission method, characterized in that determined based on the channel quality information. According to claim 1,
A method for transmitting data, characterized in that a separate DeModulation Reference Signal (DM-RS) is applied to every PUSCH repetition. According to claim 1,
Further comprising the step of receiving information on the number of basic (default) repeated transmission for uplink transmission from the base station,
The downlink control information,
and information on a difference value between the basic number of repeated transmission and the actual number of repeated transmission of the uplink data. In a terminal for transmitting data in a wireless communication system,
Receives configuration information for adjusting the range of frequency hopping from the base station, receives information on the number of repeated transmissions of uplink data from the base station, and downlink control information including control information on frequency hopping ) RF unit for receiving from the base station; and
A processor that configures a physical uplink shared channel (PUSCH) repetition corresponding to the number of repeated transmissions, and performs frequency hopping in the order of PUSCH repetition,
The processor uses a plurality of RBs including a basically configured first basic resource block (RB) for the first PUSCH repetition, and for the second PUSCH repetition, a second basic RB located at a predetermined distance from the first basic RB It uses a plurality of RBs including
The predetermined interval between the first basic RB and the second basic RB is characterized in that it is determined based on the size of a bandwidth part (BWP) activated for transmission of the uplink data, the terminal. 8. The method of claim 7,
The downlink control information,
Further comprising information on the length of a mini-slot used for repeated transmission of the uplink data,
The PUSCH repetition is
The terminal, characterized in that performed in units of the mini-slot. 8. The method of claim 7,
A plurality of RBs including the first RB and a plurality of RBs including the second RB are frequency resources corresponding to both ends of the activated bandwidth portion, respectively. 8. The method of claim 7,
The RF unit transmits channel quality information to the base station,
The control information on the frequency hopping is characterized in that determined based on the channel quality information, the terminal. 8. The method of claim 7,
A terminal, characterized in that a separate DM-RS (DeModulation Reference Signal) is applied for every PUSCH repetition. 8. The method of claim 7,
The RF unit receives information on the number of default repeated transmissions for uplink transmission from the base station,
The downlink control information, the terminal, characterized in that it includes information on a difference value between the number of basic repeated transmission and the actual number of repeated transmission of the uplink data. A method for a base station to receive data in a wireless communication system, the method comprising:
It transmits configuration information for adjusting the range of frequency hopping to the terminal, transmits information on the number of repeated transmissions of uplink data to the terminal, and downlink control information including control information on frequency hopping (downlink control information) ) RF unit for transmitting to the terminal; and
A processor for decoding a physical uplink shared channel (PUSCH) repetition corresponding to the number of repeated transmissions,
Frequency hopping is performed in the order of the PUSCH repetition,
The frequency hopping uses a plurality of RBs including a first basic resource block (RB) configured by default for the first PUSCH repetition, and for the second PUSCH repetition, a second base located at a predetermined distance from the first basic RB Multiple BRs including RB are used,
The method, characterized in that the predetermined interval between the first basic RB and the second basic RB is determined based on the size of a bandwidth part (BWP) activated for transmission of the uplink data. 14. The method of claim 13,
The downlink control information,
Further comprising information on the length of a mini-slot used for repeated transmission of the uplink data,
The PUSCH repetition is characterized in that performed in units of the mini-slot, the method. 14. The method of claim 13,
A plurality of RBs including the first RB and a plurality of RBs including the second RB are frequency resources corresponding to both ends of the activated bandwidth portion, respectively. 14. The method of claim 13,
The RF unit receives channel quality information from the terminal,
The control information on the frequency hopping is characterized in that determined based on the channel quality information. 14. The method of claim 13,
A method, characterized in that a separate DM-RS (DeModulation Reference Signal) is applied for every PUSCH repetition. 14. The method of claim 13,
The RF unit transmits information on the number of default repeated transmissions for uplink transmission to the terminal,
The downlink control information, characterized in that it includes information about a difference value between the number of basic repeated transmission and the actual number of repeated transmission of the uplink data.

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