Data transmission method and related device for ultra-low delay and high reliability communication in wireless communication system

Abstract

The present invention provides a method and related apparatus for repeated transmission in a wireless communication system to solve ultra-low latency and high reliability communication. The method for transmitting data by a terminal according to an embodiment of the present invention comprises: a step of receiving information related to the number of repeated transmissions of a physical uplink shared channel (PUSCH) from a base station; a step of receiving frequency hopping information applicable to repeated transmission of the PUSCH from the base station; a step of constructing repeated transmission of the PUSCH; a step of determining frequency resources for repeated transmission of the PUSCH based on the frequency hopping information; and a step of executing repeated transmission of the PUSCH.

Description

Technical Field

[0001] The present invention relates to a wireless communication system data transmission method and device, which are used for high-reliability ultra-low delay communication. Background Art

[0002] In order to complete the communication in various application fields of the 5G URLLC (Ultra-Reliable and Low Latency Communication) communication solution, a faster and more stable data transmission method is required. However, in an environment where the terminal moves quickly and the channel is getting weaker and weaker, data may be erroneous, so there is a need to retransmit the relevant data.

[0003] When transmitting general data, there will be no big problem even if the data is sent again. However, if URLLC data is transmitted, there will be a problem of continuous delay (latency) when it is sent again. Summary of the invention

[0004] Problems to be solved by the invention

[0005] The technical problem of the present invention is to provide a method for stably transmitting data in a short time.

[0006] Another technical problem of the present invention is to provide a device that can stably transmit data in a short time.

[0007] Another technical problem of the present invention is to provide a method for transmitting data, which is based on a CBG (code block group) scheme similar to URLLC that transmits data stably and with low latency in a short time when the amount of data is small and the data needs to be transmitted.

[0008] Another technical problem of the present invention is to provide a device for transmitting data, which is used for transmitting data when the amount of data is small and the data needs to be transmitted based on a CBG scheme similar to the URLLC scheme that transmits data stably and with low latency in a short time.

[0009] Solutions for solving problems

[0010] According to an embodiment of the present invention, a terminal data transmission method of a wireless communication system includes: a step of receiving downlink control information including information on the number of repeated transmissions of physical uplink data and frequency hopping related information from a base station; a step of forming a plurality of PUSCHs (physical uplink shared channels) corresponding to the repeated transmissions; a step of mapping the same uplink data onto the plurality of PUSCHs and determining frequency resources for repeated transmission of the PUSCHs based on the frequency hopping information; a range of the frequency hopping is changed according to the size of a bandwidth part (bandwidthpart) activated for repeated transmission of the PUSCHs.

[0011] According to an example, the downlink control information further includes: length information of a mini-slot used in the repeated transmission of the uplink data; and the repeated transmission of the plurality of PUSCHs is transmitted in units of the mini-slot.

[0012] According to one example, the frequency resources are frequency resources corresponding to both ends of the activated bandwidth portion.

[0013] According to another example, before the receiving step, the method further includes: transmitting channel quality information to the base station; and the frequency hopping information is determined based on the channel quality information.

[0014] According to another example, the frequency hopping information includes: information on whether the frequency hopping is applicable; and related information on the frequency hopping mode.

[0015] According to another example, before the receiving step, it also includes: a step of receiving information on a preset (default) number of repeated transmissions transmitted by the base station to the uplink, and the downlink control information includes information on the difference value between the preset number of repeated transmissions and the actual number of repeated transmissions of the downlink data.

[0016] According to another embodiment of the present invention, a method for transmitting data by a terminal in a wireless communication system comprises: a step of determining whether frequency hopping is applicable to uplink data of the terminal based on channel quality information received from the terminal; a step of transmitting downlink control information including information on the number of repeated transmissions of the uplink data and the frequency hopping information to the terminal; and a step of receiving from the terminal a plurality of PUSCHs corresponding to the number of repeated transmissions by determining frequency resources based on the frequency hopping information; the uplink data is uniformly mapped onto the plurality of PUSCHs, and the frequency hopping range can be changed according to the size of the bandwidth portion activated for repeated transmissions of the PDSCH.

[0017] According to another embodiment of the present invention, a method for transmitting data by a terminal in a wireless communication system includes: a step of transmitting multiple PDSCHs (physical downlink shared channels) uniformly mapped with first data to the terminal; a step of receiving feedback of the multiple PDSCHs from the terminal; and a step of determining the number of repeated transmissions of second data based on the feedback.

[0018] According to another example, before the transmitting step, the method further includes: transmitting the RRC (Radio Resource Control) signal to the terminal, wherein the RRC signal includes at least one of a maximum number of repetitions of downlink data and a preset number of repetitions. The multiple PDSCHs are determined based on the maximum number of repetitions or the preset number of repetitions.

[0019] According to another embodiment, the feedback includes ACK or NACK for the multiple PDSCHs respectively, and the number of repeated transmissions of the second data is determined based on at least one of the number of ACKs and the number of NACKs included in the feedback.

[0020] According to another embodiment, the determining step further includes: when the value of ACK or NACK included in the feedback exceeds a reference value, or the ratio between the ACK and NACK exceeds a reference ratio, the step of changing the number of repeated transmissions of the second data.

[0021] According to another embodiment, the number of repeated transmissions of the second data is changed if a channel environment when the second data is transmitted corresponds to a channel environment when the first data is transmitted.

[0022] According to another embodiment, after the determining step, the method further includes: transmitting downlink control information including relevant information about the number of repeated transmissions of the second data to the terminal.

[0023] According to another embodiment, the downlink control information includes: information on a difference between the first number of data repetition transmissions and the second number of data repetition transmissions.

[0024] According to another embodiment of the present invention, a method for transmitting data by a terminal in a wireless communication system includes: a step of constructing and transmitting a plurality of PUSCHs (physical uplink shared channels) uniformly mapped with first data to a base station; a step of receiving feedback of the plurality of PUSCHs from the base station; a step of receiving information on the number of repeated transmissions determined based on the feedback from the base station; and a step of performing repeated transmission of second data based on the information on the number of repeated transmissions.

[0025] According to another embodiment of the present invention, a method for transmitting data by a terminal in a wireless communication system comprises: a step of receiving feedback of uplink data to be transmitted by the terminal from the base station; a step of determining whether to retransmit the uplink data based on the feedback; a step of determining the size of a code block group for the uplink data based on the type of the uplink data if the uplink data is to be retransmitted; and a step of retransmitting the uplink data to the adjusted code block group unit.

[0026] According to another embodiment, the uplink data includes URLLC (Ultra-Reliable and Low Latency Communication) data, and the size of the code block group can be set to be smaller than the size of the code block group used for retransmission of eMBB (enhanced Mobile Broad Band) data.

[0027] According to another embodiment, before the receiving step, it also includes: a step of receiving size information of the code block group used for retransmission of the URLLC data from the base station through at least one of an RRC (radio resource control) message and downlink control information.

[0028] According to another embodiment, the information on the size of the code block group may be information on the maximum number of code block groups in the URLLC data transmission block.

[0029] According to another embodiment, the maximum number of code module groups for each transmission block of the URLLC data can be set independently without being affected by the maximum number of code module groups for the eMBB data.

[0030] According to another aspect of the present invention, in a wireless communication system, a method for transmitting data by a base station comprises: a step of the base station receiving feedback of downlink data transmitted from the terminal; a step of determining whether to retransmit the downlink data based on the feedback; a step of setting a code block group size of the downlink data based on the type of the downlink data when retransmitting the downlink data; and a step of retransmitting the downlink data to the adjusted code block group unit.

[0031] According to another aspect of the present invention, a method for transmitting data by a base station in a wireless communication system includes: a step of receiving information related to the number of repeated transmissions of a physical uplink shared channel (PUSCH) from a base station; a step of receiving frequency hopping information applicable to repeated transmissions of the PUSCH from the base station; a step of constructing repeated transmissions of the PUSCH; a step of determining frequency resources used for repeated transmissions of the PUSCH based on the frequency hopping information; and a step of executing repeated transmissions of the PUSCH.

[0032] According to another aspect of the present invention, the frequency hopping range is changed according to the size of a bandwidth part (BWP) activated for repeated transmission of the PUSCH.

[0033] According to another aspect of the present invention, the method further includes: receiving length information of a mini-slot used in repeated transmission of the PUSCH; and the repeated transmission of the PUSCH is performed in units of the mini-slot.

[0034] According to another aspect of the present invention, the frequency resources are frequency resources corresponding to both ends of the activated bandwidth portion.

[0035] According to another aspect of the present invention, the data transmission method further includes: a step of transmitting channel quality information to the base station; and the frequency hopping information is determined based on the channel quality information.

[0036] According to another aspect of the present invention, the frequency hopping information includes: information on whether the frequency hopping is applicable; and information on the frequency hopping mode.

[0037] According to another aspect of the present invention, the information related to the number of repeated transmissions includes: information about a default number of repeated transmissions, and information about a difference between the default number of repeated transmissions and an actual number of repeated transmissions of the PUSCH.

[0038] According to another form of the present invention, the related information of the number of repeated transmissions, as an RRC (Radio Resource Control) message, includes at least a maximum number of repeated transmissions and at least one of a preset number of repeated transmissions, and the repeated transmission of the PDSCH is determined based on the maximum number of repeated transmissions or the preset number of repeated transmissions.

[0039] According to another form of the present invention, the data transmission method also includes: a step of transmitting to the terminal relevant information about a new number of repeated transmissions determined based on an ACK or NACK of the repeated transmission of the PDSCH; and a step of performing new PDSCH repeated transmissions based on the relevant information about the new number of repeated transmissions.

[0040] According to another aspect of the present invention, the information related to the new number of repeated transmissions will be changed if the value of the ACK or NACK exceeds a reference value, or the ratio between the ACK and NACK exceeds a reference ratio.

[0041] According to another aspect of the present invention, a method for transmitting data by a base station in a wireless communication system includes: a step of transmitting relevant information about the number of repeated transmissions of a physical downlink shared channel (PDSCH) to a terminal; a step of transmitting frequency hopping information applicable to the repeated transmission of the PDSCH to the terminal; a step of constructing the repeated transmission of the PDSCH; a step of determining frequency resources used for the repeated transmission of the PDSCH based on the frequency hopping information; and a step of executing the repeated transmission of the PDSCH.

[0042] According to another aspect of the present invention, the frequency hopping range is changed according to the size of a bandwidth part (BWP) activated for repeated transmission of the PDSCH.

[0043] According to another aspect of the present invention, the data transmission method further includes: a step of transmitting length information of a mini-slot used in repeated transmission of the PDSCH to a terminal; the repeated transmission of the PDSCH is performed in units of the mini-slot.

[0044] According to another aspect of the present invention, the frequency resources are frequency resources corresponding to both ends of the activated bandwidth portion.

[0045] According to another aspect of the present invention, the data transmission method further includes: a step of receiving channel quality information from the terminal; and the frequency hopping information is determined based on the channel quality information.

[0046] According to another aspect of the present invention, the frequency hopping information includes: information on whether the frequency hopping is applicable; and information on the frequency hopping mode.

[0047] According to another aspect of the present invention, the information related to the number of repeated transmissions includes: information about a default number of repeated transmissions, and information about a difference between the default number of repeated transmissions and an actual number of repeated transmissions of the PUSCH.

[0048] According to another form of the present invention, the related information of the number of repeated transmissions, as an RRC (Radio Resource Control) message, includes at least a maximum number of repeated transmissions and at least one of a preset number of repeated transmissions, and the repeated transmission of the PDSCH is determined based on the maximum number of repeated transmissions or the preset number of repeated transmissions.

[0049] According to another form of the present invention, the data transmission method further includes: a step of transmitting relevant information about a new number of repeated transmissions determined based on an ACK or NACK of the repeated transmission of the PDSCH to the terminal; and a step of performing new PDSCH repeated transmissions based on the relevant information about the new number of repeated transmissions.

[0050] According to another aspect of the present invention, the information related to the new number of repeated transmissions will be changed if the value of the ACK or NACK exceeds a reference value, or the ratio between the ACK and NACK exceeds a reference ratio.

[0051] Effects of the Invention

[0052] According to the contents recorded in the embodiments of the present invention, if the transmission signal belongs to URLLC (ultra-reliable low latency communication), the transmitter can use frequency hopping technology based on the slit to repeatedly transmit the same data more than twice, thereby achieving faster and more stable signal transmission.

[0053] Furthermore, the number of repeated data transmissions can be optimally adjusted, thereby reducing the overhead of HARQ feedback.

[0054] Furthermore, when URLLC data is transmitted based on HARQ, the time delay can be reduced, and from the perspective of the necessity of transmission allocation and resource utilization, the signal can be efficiently retransmitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is a conceptual diagram illustrating a wireless communication system in an embodiment of the present invention.

[0056] Figure 2 is an exemplary diagram illustrating an NR system to which a data transmission method is applicable in an embodiment of the present invention.

[0057] Figure 3 FIG. 1 is a diagram illustrating a slit structure in a data transmission method according to an embodiment of the present invention.

[0058] Figure 4 FIG. 1 is a diagram illustrating a mini slit structure in a data transmission method according to an embodiment of the present invention.

[0059] Figure 5 It is a drawing illustrating a configuration method applicable to the technical features of the present invention and a BWP example.

[0060] Figure 6 This is a diagram illustrating an example of transmission in a bandwidth adaptation manner by changing the BWP and multiple BWPs to which the technical features of the present invention are applied.

[0061] Figures 7 to 13 FIG. 4 is a flow chart illustrating a frequency hopping method according to an embodiment of the present invention.

[0062] Fig.14 is a flow chart illustrating a data transmission method according to an embodiment of the present invention.

[0063] Fig.15 is a flow chart illustrating a data transmission method according to another embodiment of the present invention.

[0064] Fig.16is a flow chart illustrating a data transmission method according to another embodiment of the present invention.

[0065] Fig.17 FIG. 2 is a diagram illustrating the concept of a code block group used in the present invention.

[0066] Fig.18 FIG. 1 is a diagram illustrating a PDSCH serving cell structure applicable to an embodiment of the present invention.

[0067] Fig.19 FIG. 1 is a diagram illustrating a PUSCH serving cell structure according to an embodiment of the present invention.

[0068] Fig. 20 It is a diagram for illustrating a situation in which eMBB data is retransmitted according to an embodiment of the present invention.

[0069] Fig.21 It is a drawing used to illustrate the situation of retransmitting URLLC data in one embodiment of the present invention.

[0070] Fig. 22 is a flowchart illustrating a data transmission method in another embodiment of the present invention.

[0071] Fig.23 It is a structural framework diagram of a wireless communication system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0072] The present invention can be subjected to various deformations and can also have various forms of embodiments. For specific embodiments, examples will be given by way of drawings and detailed descriptions will be given. However, this is not limited to the forms of specific embodiments of the present invention. The technical ideas and technical scope of the present invention include all deformations, equivalents and even substitutes, which should be understood in this way. When describing each of the drawings, similar structural elements will be marked with similar reference numerals.

[0073] The terms "first", "second", "A", "B" and the like used in the present invention are used to describe various structural elements, but the structural elements are not limited to the above terms. The purpose of the above terms is to distinguish one structural element from other structural elements. For example, if it is out of the scope of the claims of the present invention, the first structural element can be named as the second structural element, and the similar second structural element can also be named as the first structural element. And the terms such as "and / or" include a combination of multiple related recorded items or one of multiple related recorded items.

[0074] When a certain structural element is recorded as "interconnected" or "in contact with each other" with another structural element, it can be understood that it is directly connected or in contact with the other structural element, but it can also be understood that there are other structural elements in between. On the contrary, when a certain structural element is recorded as "directly connected" or "directly in contact with" with another structural element, it should be understood that there are no other structural elements in between.

[0075] The terms used in this specification are only used to describe specific embodiments, so it is not intended to limit the present invention. If a single expression does not clearly represent other meanings in the context, it also includes multiple meanings. In this specification, the terms "including" or "having" should be understood to include the existence of the features, numbers, steps, actions, structural elements, parts or combinations of these recorded in the specification, or do not exclude the existence of one or more other features, numbers, steps, actions, structural elements, parts or combinations of these, or add other possibilities.

[0076] The terms used in this specification, if not otherwise defined, including technical or scientific terms, are the same as those understood by ordinary technicians working in the technical field of the present invention. It should be considered that similar terms usually used or defined in dictionaries have the same meaning as the overall context of the relevant technology, and if not clearly defined separately in this specification, they should not be analyzed and understood as having too high or excessive formal meanings.

[0077] The following content will describe in detail the preferred embodiments of the present invention with reference to the accompanying drawings.

[0078] Figure 1 is a conceptual diagram illustrating a wireless communication system in an embodiment of the present invention.

[0079] Reference Figure 1 , the wireless communication system 100 is composed of a plurality of communication nodes 110 - 1 , 100 - 2 , 100 - 3 , 120 - 1 , 120 - 2 , 130 - 1 , 130 - 2 , 130 - 3 , 130 - 4 , 130 - 5 , and 130 - 6 .

[0080] Multiple communication nodes can support at least one communication protocol. For example, multiple communication nodes can respectively support a communication protocol based on a CDMA (Code Division Multiple Access) system, a communication protocol based on a WCDMA (Wideband CDMA) system, a communication protocol based on a TDMA (Time Division Multiple Access) system, a communication protocol based on an FDMA (Frequency Division Multiple Access) system, a communication protocol based on an OFDM (Orthogonal Frequency Division Multiplexing) system, a communication protocol based on an OFDMA (Orthogonal Frequency Division Multiple Access) system, a communication protocol based on an SC (Single Carrier)-FDMA system, a communication protocol based on a NOMA (Non-Orthogonal Multiple Access) system, and a communication protocol based on an SDMA (space division multiple access) system.

[0081] The wireless communication system 100 may include 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 , and 130 - 6 .

[0082] The first base station 110-1, the second base station 110-2, and the third base station 110-3 respectively form a macrocell structure. The fourth base station 120-1 and the fifth base station 120-2 respectively form a small cell structure. The coverage of the first base station 110-1 includes the fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4. The coverage of the second base station 110-2 includes the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5. The coverage of the third base station 110-3 includes the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6. The coverage of the fourth base station 120-1 includes the first terminal 130-1. The coverage of the fifth base station 120-2 includes the sixth terminal 130-6.

[0083] Here, multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may respectively refer to Node B, evolved Node B, next generation Node B (gNB), BTS (Base Transceiver Station), radio base station, radio transceiver, access point, access node, 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), relay node, and the like. The multiple terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may respectively refer to a circuit terminal (terminal), an access terminal (access terminal), a mobile terminal (mobile terminal), a base station (station), a user base station (subscriber station), a terminal base station (mobile station), a portable user base station (portable subscriber station), a node (node), a device (device), etc.

[0084] 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 respectively support cellular communications (e.g., LTE (long term evolution), LTE-A (advanced), NR (new Radio)) and the like specified in the standards of the 3GPP 3rd Generation Partnership Project. A plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in different frequency bands, and may also operate in the same frequency band. The plurality of base stations 110-1, 110-2, 110-3, 120-1, 120-2 may be connected respectively through an ideal backhaul or a non-ideal backhaul, and exchange information between each other through the ideal backhaul or the non-ideal backhaul. The multiple 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 signal tunnel or an imperfect signal tunnel. The multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may transmit signals received from the core network to corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6, respectively; and transmit signals received from corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 to the core network.

[0085] Multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can respectively support downlink transmission based on OFDMA, and can also support uplink transmission based on OFDMA or SC-FDMA. In addition, multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can respectively support MIMO (Multiple Input Multiple Output) transmission (for example, SU (Single User)-MIMO, MU (Multi User)-MMO, massive MIMO, etc.), CoMP (Coordinated Multipoint) transmission, carrier aggregation transmission, transmission in unlicensed band, end-to-end (D2D, device to device) communication (or ProSe (proximity Here, the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 respectively perform actions corresponding to the base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and / or perform actions supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2.

[0086] For example, the second base station 110-2 can transmit a signal to the fourth terminal 130-4 based on the SU-MIMO method, and the fourth terminal 130-4 can receive a signal from the second base station 110-2 by relying on the SU-MIMO method. At the same time, the second base station 110-2 can transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 based on the SU-MIMO method, and the fourth terminal 130-4 and the fifth terminal 130-5 respectively receive a signal from the second base station 110-2 in the SU-MIMO method. The first base station 110-1, the second base station 110-2 and the third base station 110-3 can respectively transmit a signal to the fourth terminal 130-4 based on the CoMP method, and the fourth terminal 130-4 can receive a signal from the first base station 110-1, the second base station 110-2 and the third base station 130-3 based on the CoMP method. Multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can transmit and receive signals based on each terminal 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 within their respective coverage areas and the CA method.

[0087] The first base station 110-1, the second base station 110-2 and the third base station 110-3 assist the fourth terminal 130-4 and the fifth terminal 130-5 in D2D communication respectively; the fourth terminal 130-4 and the fifth terminal 5 perform D2D communication with the second base station 110-2 and the third base station 110-3 respectively through assistance.

[0088] The following content is a description of the method (e.g., signal transmission and reception) performed by the first communication node among the communication nodes. At this time, the corresponding second communication node can also perform the method corresponding to the method performed in the first communication node (e.g., signal reception or transmission). That is, when the operation of the terminal is described, the corresponding base station can perform the operation action corresponding to the operation action of the terminal. Conversely, when the operation of the base station is described, the corresponding terminal can perform the operation action corresponding to the operation action of the base station.

[0089] In addition, in the following, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In the downlink, the transmitter may be part of the base station, and the receiver may be part of the terminal. In the uplink, the transmitter may be part of the terminal, and the receiver may be part of the terminal.

[0090] Recently, the popularity of smart phones and IoT (Internet of Things) terminals is rapidly spreading, and the amount of information transmitted through the communication network has increased significantly. Therefore, the real environment requires that the next-generation radio transmission technology can provide faster services to more users (for example, enhanced mobile broadband communication) than the existing communication system (or existing radio access technology), and it is necessary to think deeply and develop this. For this reason, the design of a new communication system MTC (Machine Type Communication) is currently under discussion to connect a larger number of machines and objects and provide better services. In addition, the reliability of the communication system and / or the design of services that are very sensitive to latency and / or communication systems involving terminals (for example, URLLC (Ultra-Reliable and Low Latency Communication)) is under discussion.

[0091] In the following specification, for the convenience of explanation, the new generation of wireless transmission technology is referred to as NewRAT (Ratio Access Technology), and the wireless communication system used by the New RAT is referred to as the NR (New Radio) system.

[0092] Figure 2 is an exemplary diagram illustrating an NR system to which a data transmission method is applicable in an embodiment of the present invention.

[0093] Reference Figure 2 NG-RAN (Next Generation-Radio Access Network) consists of gNBs that provide the NG-RA user plane (SDAP / PDCP / RCC / MAC / PHY) and UE (User Equipment) control plane (RRC) protocol ends. (NG-RAN may also include existing LTE base stations eNB.) Here, the NG-C shows the control plane interface applicable to the NG2 reference point between NG-RAN and 5GC (5Generation Core). The NG-U shows the user plane interface applicable to the NG3 reference point between NG-RAN and 5GC.

[0094] gNBs are connected to each other through the Xn interface and to 5GC through the NG interface. More specifically, gNB is connected to AMF (Access and Mobility Management Function) through the NG-C interface and to UPF (UserPlane Function) through the NG-U interface.

[0095] Figure 2 Multiple numerologies can be supported in NR systems. The numerologies here can be defined by the overhead of the subcarrier spacing (SCS) and the cyclic prefix (CP). That is, multiple carrier spacings can be guided by scaling the carrier spacing by integer ratios. And even if it is assumed that very low carrier spacing is not applicable in very high carrier frequencies, different frequency bands can be selected independently for the numerology.

[0096] In addition, multiple framework structures based on multiple parameter sets can be supported in the NR system. Figure 3 The OFDM parameter set and framework structure used in the data transmission method in the embodiment of the present invention are described.

[0097] Figure 32 is a diagram illustrating a slit structure used in a data transmission method according to an embodiment of the present invention.

[0098] The TDD (Time Division Duplexing) structure being designed in the NR system is a structure that processes the uplink (UL) and downlink (DL) in one slot (or subframe). This is a design structure that can minimize data transmission latency in the TDD system, and can also be called a self-contained structure or a self-contained slot.

[0099] Reference Figure 3 , a single slot can be composed of 14 OFDM symbols (when using Extended CP, it is composed of 12 PFDM symbols). Figure 3 The area 310 in the figure is the downlink control region, and the area 320 is the uplink control region. Figure 3 The difference from the content presented in FIG. 3 is that the number of symbols used in the uplink and downlink control fields in a single slot is more than 1 respectively. The area outside the area 310 and the area 320 (i.e., other unmarked areas) can be used for the transmission of downlink data or uplink data. That is, the uplink control information and the downlink control information are transmitted from a single slot. And, when data is transmitted, the uplink data and the downlink data are transmitted from a single slot.

[0100] If you use Figure 3 In the structure, downlink transmission and uplink transmission can be performed in a single slot, and downlink data transmission and uplink ACK / NACK reception are performed. Therefore, if a data transmission error occurs, the time required for retransmission of the data can be reduced. In this way, the delay associated with data transmission can be minimized.

[0101] exist Figure 3 In the slot structure in the UE, a time gap is generated when the base station and / or the terminal switches from the transmission mode to the reception mode or from the reception mode to the transmission mode. As for the time gap, when performing uplink transmission after downlink transmission in the slot, part of the OFDM symbols can be set as a guard period (GP).

[0102] Figure 4 FIG. 1 is a diagram illustrating a mini slit structure in a data transmission method according to an embodiment of the present invention.

[0103] According to an embodiment of the present invention, in order to efficiently support URLLC, in addition to supporting the scaling of the slit unit, the mini-slot unit scaling is also supported. (The transmission method based on the mini-slot is also called the non-slot transmission method) The mini-slot, as the minimum scaling unit based on the base station, can be transmitted to a unit smaller than the slit (1 to 13 symbols). For example, it can be composed of 2, 4 or 7 OFDM symbols.

[0104] Mini slits Figure 4 As shown in the content, it can start in a certain OFDM symbol within the slit. Figure 4 Although two mini-slits with different paths (number of OFDM symbols) in a single slit are illustrated in the figure, this is a structure presented only for the convenience of explanation. If a single slit contains multiple mini-slits, the number of OFDM symbols constituting each mini-slit can also be the same.

[0105] In the NR system, in order to carry out communications in various application fields corresponding to V2X (Vehicle to Everything), URLLC scripts, etc., it is very necessary to achieve stable and fast transmission of data with almost no errors. In particular, in an environment where the terminal moves quickly, when moving in the direction of channel deterioration, based on the CQI fed back by the terminal to the base station, errors are likely to occur when the base station sets the transmission format and transmits data. Therefore, in this case, retransmission is likely to be required. If general data such as eMBB (enhanced Mobile Broad Band) data is transmitted, there will be no big problem even if retransmission occurs, but once URLLC data is retransmitted, problems may arise due to the delay caused by retransmission. In most cases of V2X scripts, URLLC scripts, etc., the amount of user data sent is not large, so using a small amount of additional resources will not cause too much burden. On the contrary, if an error occurs and the resulting retransmission causes the delay to expand, the situation may be even worse. Therefore, in the present invention, the same data can be repeatedly transmitted or repeatedly transmitted by the following method. According to the present invention, the data transmission method is not only applicable to automotive communications such as V2X, but also to various scripts of URLLC.

[0106] The following content explains the resource allocation of the NR system.

[0107] A specific number of bandwidth parts (BWPs) can be defined in the NR system (e.g., up to 4 each for downlink and uplink). A BWP (or carrier BWP) is a set of consecutive PRBs and can be represented as a set of consecutive parts of a common RB (CRB). Each RB within a CRB starts with CRB0 and displays the content in the form of CRB1, CRB2, etc.

[0108] <Repeated transmission method and device using frequency hopping>

[0109] Figure 5 It is a drawing illustrating a configuration method applicable to the technical features of the present invention and a BWP example.

[0110] Reference Figure 5 , most BWPs can define a reference point of the CRB grid in the CRB grid (which can be used as a common reference point, starting point, etc.) which is called "point A" in NR. Point A is commanded by RMSI (i.e. SIB1). Specifically, RMSI can indicate the frequency band between the frequency band transmitted by the SS / PBCH block and point A. Point A corresponds to the first subcarrier of CRB0. In addition, point A can be the location where the variable "k" indicating the RE band in NR is set to 0, such as Figure 5 The multiple BWPs shown in FIG. 1 are composed of one cell (eg, PCell (primary cell)). The multiple BWPs can constitute multiple cells individually or collectively.

[0111] Reference Figure 5 Each BWP can be defined based on the size and starting point of CRB0. For example, the first BWP, BWP#0, can be defined based on the offset of the starting point from CRB0, and the size of BWP#1 is determined by the size of BWP#0. Each BWP can be defined overlappingly within the entire channel bandwidth (CBW).

[0112] A specific number (for example, up to 4 each for downlink and uplink) of BWPs can constitute a terminal. In the 3GPP Release 15 specification, even if multiple BWPs are constituted, each cell can only activate a specific number (for example, 1) of BWPs within a specified time. Thereafter, in the relevant regulations, corresponding changes can be made to activate multiple BWPs within a specified time. However, if the SUL (supplementary uplink) constitutes the carrier on the terminal, a maximum of 4 BWPs can be constituted on the SUL carrier, and 1 BWP can be activated within a specified time. The number of BWPs or the number of activated BWPs can constitute UL and DL in a common or individual manner. In addition, the parameter set and / or CP of the DLBWP, the parameter set and / or CP of the ULBWP can be set in the terminal through the DL signal. The terminal can only receive PDSCH, PDCCH, CSI (channel state information) RS and / or TRS (tracking RS) in the activated DLBWP. In addition, the terminal can only transmit PUSCH and / or PUCCH (physical uplink control channel) on the activated UL BWP.

[0113] Figure 6 This is a diagram showing an example of multiple BWPs to which the technical features of the present invention are applied and a BWP is changed to perform bandwidth adaptation transmission.

[0114] Figure 6 The case where three BWPs are assumed to be set. The first BWP can span a 40MHz bandwidth and can also apply a 15kHz subcarrier spacing. The second BWP can span a 10MHz bandwidth and can apply a 15kHz subcarrier spacing. The third BWP can span a 20MHz bandwidth and can apply a 60kHz subcarrier spacing. The terminal can be composed of at least one active BWP group among the three BWPs and perform UL and / or DL ​​data communication through the active BWP.

[0115] The time resource is based on the transmission time point of the PDCCH that allocates DL or UL resources and receives the command in a time difference / difference manner. For example, the command can be received based on the starting point of the PDSCH / PUSCH corresponding to the PDCCH and the number of symbols occupied by the PDSCH / PUSCH.

[0116] The NR system is similar to LTE / LTE-A and can support carrier aggregation (CA). That is, by integrating continuous or discontinuous component carriers (CCs), the bandwidth is increased, and the bit rate is ultimately increased. Each CC can correspond to a (serving) cell, and each CC / cell can be divided into PSC (primary serving cell) / PCC (primary CC) or SSC (secondary serving cell) / SCC (secondary CC).

[0117] In addition, NR systems can support single beam and multi-beam forming.

[0118] The network can configure single beams and multiple beams. Different single beams can be used at different times. It does not matter whether single beams or multiple beams are configured. From the UE perspective, it is necessary to mark the monitoring resources in order to monitor the control channel. Especially when using or reusing multiple beams, from the UE perspective, the same control channel can be transmitted multiple times.

[0119] In order to communicate with various application fields corresponding to V2X (Vehicle to Everything), URLLC scripts, etc. in the NR system, it is necessary to transmit data stably and quickly without errors. In particular, in an environment where the terminal moves quickly, when moving in the direction of the channel deterioration, based on the CQI fed back by the terminal to the base station, the base station sets the transmission format and transmits the data. It is very likely that an error will occur, so there will be a need for retransmission. If general data such as eMBB (enhanced Mobile Broad Band) data is transmitted, there will be no big problem even if retransmission occurs, but once URLLC data is retransmitted, problems may arise due to the latency caused by retransmission. In most cases such as V2X scripts and URLLC scripts, the amount of user data sent is not large, so using a small amount of additional resources will not cause too much burden. On the contrary, if an error occurs and the retransmission caused by the error causes the delay to expand, the situation may be even worse. Therefore, in the present invention, the same data can be repeatedly transmitted or retransmitted by the following method. The data transmission method in the present invention is not only applicable to automotive communications such as V2X, but also to various scripts of URLLC.

[0120] Figures 7 to 13 FIG. 4 is a flow chart illustrating a frequency hopping method according to an embodiment of the present invention.

[0121] According to this embodiment, when the transmitter repeatedly or repeatedly transmits the same information (same data) to the receiver, frequency hopping (FH) can be performed in the frequency region. Here, if the transmitter is a terminal, the receiver can be a base station or other terminals. If the transmitter is a base station, the receiver can be a terminal.

[0122] For example, when the terminal repeatedly transmits the same data to the base station, it can perform frequency hopping in the frequency region in units of mini-slots. For example, after setting multiple PUSCHs corresponding to the number of repeated transmissions on the terminal, the first PUSCH can be transmitted to the base station using the first frequency on the first mini-slot, and the second PUSCH can be transmitted to the base station using the second frequency on the second mini-slot adjacent to the first mini-slot in time. Here, the same uplink data on each PUSCH can be uniformly mapped.

[0123] To give another example, when the base station repeatedly transmits the same data to the terminal, it can perform frequency hopping within the frequency region in units of mini-slots. For example, after the base station sets multiple PDSCHs corresponding to the number of repeated transmissions, the first PDSCH can be transmitted to the terminal using the first frequency on the first mini-slot, and the second PUSCH can be transmitted to the terminal using the second frequency in the second mini-slot adjacent to the first mini-slot in time. Here, the same downlink data on each PDSCH can be uniformly mapped.

[0124] This embodiment is also applicable to the transmission environment of the side chain.

[0125] In this case, the transmitter becomes the transmitting terminal and the receiver becomes the receiving terminal. The data transmitted through the side link can be called PSSCH or PSSCH data, which can also be said to be URLLC related data.

[0126] In addition, in this embodiment, the frequency range used for frequency modulation varies according to the size of the BWP (bandwidth part). For example, in order to maximize the frequency diversity effect, the transmitter can use frequency resources equivalent to the two ends of the BWP on the FH. Figure 7 As shown, the BWP consists of 10 PRBs (PRB#0 to PRB#9) and 4 repeated transmissions are set. At this time, the transmitter can use PRB#0, the lowest frequency resource in the BPP, to transmit the same data in the first mini-slot and the third mini-slot, and can use PRB#9, the highest frequency resource in the BPP, to transmit the same data in the second mini-slot and the fourth mini-slot.

[0127] In addition, the transmitter and Figure 7Differently, the same data may be transmitted using PRB#9 in the first mini-slot and the third mini-slot, and the same data may be transmitted using PRB#0 in the second mini-slot and the fourth mini-slot.

[0128] On the other hand, when more frequency resources (RBs) are needed for data transmission, the transmitter can increase the number of RBs from the end of the BWP and use multiple frequency resources at the same time. Figure 8 As shown in FIG. 1 , when a BWP is composed of 10 PRBs (PRB#0 or PRB#9) and 4 repetitions are set, the transmitter uses PRB#0 and PRB#1 to transmit the same data in the first and third slots, and can use PRB#8 and PRB#9 to transmit the same data in the second and fourth slots. Figure 8 Differently, in the first and third slits, PRB#8 and PRB#9 are used to transmit the same data, and in the second and fourth slits, PRB#0 and PRB#1 can be used to transmit the same data.

[0129] In addition, when there is too much URLLC communication volume that is suitable for frequency hopping, frequency resource collisions should be avoided as much as possible. In particular, when user resources overlap in frequency hopping between multiple terminals, the range of frequency hopping needs to be adjusted to ensure that frequency resources do not conflict. For this reason, if frequency hopping is adopted, the frequency resources at the end of the BWP can basically be used, but corresponding adjustments can be made in different situations. For example, 4 repeated transmissions are set for the first terminal and the second terminal, and when the frequency hopping resources of the first terminal and the frequency hopping resources of the second terminal overlap, Fig. 9 As shown in the content, the first terminal can use frequency hopping to repeatedly transmit the same data to the mini-slot unit based on the most basic set frequency resources PRB#0 and PRB#9 for frequency hopping; the second terminal can use frequency hopping to repeatedly transmit the same data to the mini-slot unit based on the most basic set frequency resources PRB#1 and PRB#8 by adjusting the frequency hopping range within the BWP. In addition, Fig.10 As shown in the content, the first terminal and the second terminal all adjust the frequency hopping range, the first terminal can use PRB#0 and PRB#8 to repeatedly transmit data, and the second terminal can use PRB#1 and PRB#9 to repeatedly transmit data. Fig.11 As shown in the content, the first terminal and the second terminal can use the same frequency resources, but use different frequency hopping patterns to repeatedly transmit the same data.

[0130] On the other hand, in order to reduce the complexity when repeatedly transmitting the same data, frequency hopping may not be performed within the mini-slot. If multiple mini-slots are used to repeatedly transmit the same data, frequency hopping may be used. If repeated or repetitive transmission occurs in multiple slots, a different frequency may be used in the next slot than in the previous slot. That is, FH may be applied between slots. At this time, for example, if the base station or the transmitting terminal can rely on channel information (channel gain by frequency band), frequency hopping may not be applied, but frequency resources with good channel status may be allocated to repeatedly transmit data.

[0131] Information related to this frequency hopping, such as FH-related setting information, is set to semi-static by the base station using the upper layer protocol RRC (Radio Resource Control) signal and the like, and notified to the terminal. In addition, the control information related to FH can be included in the DCI and transmitted to the PDCCH. In the sidelink transmission environment, the FH-related information can be transmitted by the base station to the terminal through the signal of the upper layer protocol such as RRC, or transmitted by the transmitting terminal to the receiving terminal. For example, the base station can provide the terminal with information on whether FH is applicable, the FH mode, etc. through the DCI. That is, the base station can include the control information for data transmission in the DCI and send it to the terminal through the above-mentioned transmission method. In this case, a new field may be added to the DCI. If the transmitting terminal repeatedly or repeatedly transmits data to the receiving terminal, the transmitting terminal can provide the receiving terminal with information on whether FH is applicable, the FH mode, etc. through the SCI (Sidelink Control Information).

[0132] In terms of downlink transmission or downlink transmission, the length of the mini-band and the number of repeated transmissions can be sent by the base station through DCI and notified to the terminal. However, the number of repeated transmissions can be set by notifying in advance through RRC. For example, the base station uses RRC to notify the preset (default) number of repeated transmissions. If the preset number of repeated transmissions needs to be changed, the actual number of repeated transmissions can be notified to the terminal through DCI. At this time, the DCI may contain information about the difference between the preset number of repeated transmissions and the actual number of repeated transmissions.

[0133] In terms of side chain transmission, the length of the mini-slit and the number of repeated transmissions can be notified to the receiving terminal by the transmitting terminal or the base station through SCI or DCI.

[0134] In addition, if frequency hopping is used, a separate DMRS (DeModulation Reference Signal) can be used for each repeated transmission. However, when the transmitter uses the same frequency resource to repeatedly transmit the same data to the receiver, the DMRS may not be used alone. That is, a DM-RS can be repeatedly transmitted multiple times. However, in the case of rapid channel changes, the DM-RS can be used alone even if the same frequency resource is used. That is, a separate DM-RS can be used for each repeated transmission.

[0135] In addition, when transmitting repeatedly, the number of DM-RS used can be different according to the service or the QoS of the service. For example, when moving quickly, each repeated transmission uses a DM-RS separately, and when moving slowly, a single DM-RS can be used for repeated transmission multiple times.

[0136] On the other hand, in the case of transmitting very important information, the same information can be transmitted repeatedly in the frequency and time domains. For example, the transmitter can allocate multiple frequency resources and transmit the same information to each frequency resource. Fig.12 As shown, the transmitter can map the same data to PRB#0 and PRB#9 respectively, and transmit them to the first slot to the fourth slot. This method is more suitable in the mm-Wave environment with abundant frequency resources and short time resources.

[0137] As another example, the transmitter may use other frequency and time resources to transmit the same information multiple times. Fig.13 As shown, when the transmitter repeatedly transmits the first data, it uses PRB#0 and PRB#9 to perform frequency hopping, and for the second data that is the same as the first data, it can use the best frequency resource based on CQI ( Fig.13 RPB#5) is transmitted repeatedly.

[0138] In the above embodiment, the frequency hopping resources can be obtained based on the following Table 1:

[0139] Table 1

[0140]

[0141] Referring to Table 1, the frequency hopping offset for repeated transmission can be determined based on the number of RPBs in the activated uplink BWP. Moreover, the frequency conversion mode of the band can be determined according to the value of the frequency hopping rhythm. The method of determining the frequency conversion resource can also be applied to the downlink.

[0142] Fig.14 is a flow chart illustrating a data transmission method according to an embodiment of the present invention.

[0143] According to this embodiment, the transmitter can repeatedly transmit the same data to the receiver in a variety of ways according to the channel status. The transmitter here can be a base station or a transmitting terminal, and the receiver can be a base station or a receiving terminal.

[0144] The following examples will refer to Fig.14 , which explains the situation in which the terminal repeatedly transmits uplink data to the base station.

[0145] The base station determines whether frequency hopping is to be used for the uplink data that the terminal wants to transmit based on the CQI report received from the terminal. To this end, the terminal can confirm the channel status and transmit a CQI report to the base station (S1410). The base station confirms the channel status based on the CQI value contained in the CQI report received from the terminal. If the channel status is good, it is determined not to use frequency hopping and repeatedly transmit the corresponding data; if the channel status is not good, the channel information cannot be obtained or cannot be trusted, it can be determined to use frequency hopping for repeated transmission. In addition, the base station can transmit DCI including information related to the number of repeated transmissions of uplink data and information related to frequency hopping to the corresponding terminal for transmission. Here, in addition to the information related to the number of repeated transmissions and the information related to frequency hopping, the DCI may also include information related to the length of the mini-slot used for repeated transmission. In addition, the above-mentioned frequency hopping related information may also include: information on whether frequency hopping is applicable, and / or information on the frequency hopping mode.

[0146] After receiving the DCI from the base station, the terminal can determine whether to perform frequency hopping based on this (S1420). If it is determined that frequency hopping is not applicable and repeated transmission is performed, the terminal can repeatedly transmit the same data using the best frequency resource (S1430). At this time, the terminal can repeatedly transmit the same data using multiple frequency and / or time resources according to the importance of the data.

[0147] However, if frequency hopping is determined to be used during repeated transmission, the terminal can transmit the first data using the first frequency band in the first mini-slot (S1440). In the second mini-slot adjacent to the first mini-slot in time, the terminal can repeatedly transmit the same data as the first data to the receiver using the second frequency hopping frequency (S1450). Figures 7 to 13 At least one of the frequency hopping methods is used to repeatedly transmit the same data.

[0148] For example, after receiving DCI from the base station, the terminal forms multiple PUSCHs corresponding to the number of repeated transmissions based on the information of the number of repeated transmissions included in the DCI, and determines the frequency resources used for the transmission of multiple PUSCHs based on the frequency hopping information included in the DCI. At this time, the uplink data can be uniformly mapped on the multiple PUSCHs. In addition, during repeated transmission, the range of frequency hopping can be changed according to the size of the activated BWP to transmit the corresponding uplink data.

[0149] <Communication method based on adaptive control of the number of repeated transmissions>

[0150] Fig.15 is a flow chart illustrating a data transmission method according to another embodiment of the present invention.

[0151] In this embodiment, the transmitter may repeatedly or repeatedly transmit the same information (the same data) to the receiver. When the terminal repeatedly or repeatedly transmits data to the base station, the above data may be referred to as PUSCH or PUSCH data. Or the above data may be referred to as URLLC related data. When the base station repeatedly or repeatedly sends the same data to the terminal, the above data may be referred to as PDSCH or PDSCH data. And the above data may be referred to as URLLC related data. When the transmitting terminal repeatedly or repeatedly transmits the same data to the receiving terminal, the above data may be referred to as PSSCH or PSSCH data, or URLLC related data.

[0152] exist Fig.15 An example in which the transmitter is a base station and the receiver is a terminal is illustrated in FIG.

[0153] Reference Fig.15 , the number of repeated transmissions and the maximum number of repeated transmissions can be pre-set as semi-static or static by the base station through RRC (Radio Resource Control). For example, the base station can provide the terminal with information about the default number of repeated transmissions and / or the maximum number of repeated transmissions through an upper layer protocol signal such as RRC information (S1510). That is, the value set by RRC is the maximum number of repeated transmissions or the default number of repeated transmissions, or both can be set at the same time according to different needs.

[0154] As an example, the base station can use the first data to form multiple PDSCHs based on information about a preset number of repeated transmissions or a maximum number of repeated transmissions. That is, the first data can be mapped together to the above-mentioned multiple PDSCHs. The base station transmits the multiple PDSCHs to which the first data is mapped together to the terminal by using different time and / or frequency resources, thereby repeatedly transmitting the first data (S1520). The maximum number of repeated transmissions here can be set to a preset number of repeated transmissions. In this case, the base station can only transmit information about the maximum number of repeated transmissions using RRC information, and the terminal can identify the maximum number of repeated transmissions as the preset number of repeated transmissions.

[0155] In the receiver, ACK / NACK can be sent for each data when it is repeatedly transmitted; in the transmitter, the above situation can be considered to determine the optimal number of repeated transmissions. For example, when the terminal receives multiple PDSCHs from the base station, it decodes them (S1530), transmits HARQ ACK for the successfully received PDSCH, and transmits HARQ NACK for the erroneous PDSCH (S1540). The base station can determine the number of repeated transmissions of the second data (data repeatedly transmitted after the first data) based on the number of HARQ ACKs and / or the number of HARQ NACKs received from the terminal (S1550). At this time, when the terminal determines whether the data needs to be transmitted again, it can use the CC (Chase Combining) method and / or the IR (Incremental Redundancy) method. The CC method can be applicable when the same redundancy version is used in multiple PDSCHs, and the IR method can be applicable when different redundancy versions are used in multiple PDSCHs. For example, when a terminal decodes multiple PDSCHs, if an error occurs on the first PDSCH, the first PDSCH can be combined with the second PDSCH to modify the error on the first PDSCH and / or the second PDSCH. If errors occur on multiple PDSCHs, after successfully decoding the relevant data in combination with these results, the terminal will transmit HARQ ACK for the last received PDSCH instead of HARQ NACK. In this case, the base station can know and judge that the channel state is not good through HARQ feedback, because the corresponding data is successfully received at the terminal, so it can prevent the base station from resending the relevant data unnecessarily.

[0156] After the transmitter completes the repeated transmission, if the number of ACKs of the repeated transmission exceeds the reference value, or the ratio between the number of ACKs and the number of NACKs contained in the corresponding feedback exceeds the reference ratio, it is determined that the channel state is very good. When the next set of data is transmitted under a similar channel environment, the number of repetitions can be reduced to achieve repeated transmission. However, after the transmitter completes the repeated transmission, if the number of ACKs is lower than the standard value or the reference ratio, it is determined that the channel state is not good. When the next set of data (second data) is transmitted in a similar channel environment (an environment corresponding to the channel environment when the first data is transmitted), the number of repetitions can be increased to achieve repeated transmission. That is, the number of repeated transmissions of the second data can be adjusted and changed accordingly when the channel environment when the second data is transmitted corresponds to the channel environment when the first data is transmitted.

[0157] For example, when the base station receives multiple HARQ ACKs with PDSCH exceeding the standard from the terminal, and the second data needs to be repeatedly transmitted in a channel environment similar to the repeated transmission of the first data, the number of repeated transmissions of the second data can be reduced. Another example is that when the base station receives multiple HARQ ACKs with PDSCH failing to meet the standard from the terminal, and the second data needs to be repeatedly transmitted in a channel environment similar to the repeated transmission of the first data, the number of repeated transmissions of the second data can be increased. Afterwards, the base station informs the terminal of the information of the number of repeated transmissions of the second data through DCI, and uses the second data to form a PDSCH with the corresponding number of repeated transmissions and send it to the terminal (S560).

[0158] At this time, the base station can perform repeated transmission according to the range of the preset repeated transmission number, and then change the repeated transmission number. After completing several initial transmissions, the update of the repeated transmission number can be set to other parameters (for example: 1, 2, 4, 6... etc.).

[0159] For example, when the parameter of the number of repeated transmissions is updated and set to "2", the base station can repeatedly transmit the first data and the second data with the preset number of repeated transmissions respectively, and the number of repeated transmissions for the third data can be determined based on the number of HARQ ACK and / or NACK of the first data and / or second data.

[0160] In the subsequent repeated transmission process, within the range set by RRC, the base station can make real-time changes, and the relevant information can be included in the DCI and notified to the terminal. For example, after the base station sets several repeated transmission times with RRC in the early stage, it uses DCI to only inform the difference between the current number of repeated transmissions and the previous number of repeated transmissions. Alternatively, it is possible to only inform whether the number of repeated transmissions is up or down. For example, the base station can use RRC to set the number of repeated transmissions (2, 4, 6, 8), and the preset number of repeated transmissions can be set to "2". In this case, if the base station uses DCI to indicate that the number of repeated transmissions is to be increased, the terminal can change the preset number of repeated transmissions from "2" to "4".

[0161] In addition, the base station can use DCI to notify whether the repeated transmission is in an activated / inactivated state. Therefore, according to the content of this embodiment, the number of repeated transmissions can be optimized, and the number of ACK / NACK can be reduced accordingly.

[0162] On the other hand, in this embodiment, repeated transmission can be applied to both the time axis and the frequency axis, that is, the transmitter can use different time and / or frequency resources to dynamically set how many times the same information is to be repeatedly transmitted.

[0163] When performing repeated transmission, the more high frequency bands are used, the more repetitions there are on the frequency axis. In order to achieve ultra-low latency, it is more advantageous to perform repeated transmission on the frequency axis. However, depending on different situations, time resources can be used repeatedly. For example, the transmitter can use the first frequency source to transmit first data on the first slit or the first mini-slit, and use the second frequency resource to transmit data identical to the first data. As another example, the transmitter can use the first frequency resource to transmit first data on the first slit or the first mini-slit, and use the first frequency resource or the second frequency resource to transmit data identical to the first data on the second slit or the second mini-slit slot adjacent to the first slit or the first mini-slit in time.

[0164] On the other hand, as another embodiment, the number of repeated transmissions may change according to the channel status such as CQI. For example, the transmitter may reduce the number of repeated transmissions when the channel status is good, and increase the number of repeated transmissions when the channel status is bad. Information on the increase and / or decrease of the number of repeated transmissions may be transmitted to the receiver via DCI, SCI, UCI, etc. In this case, it is more appropriate to set the number of repeated transmissions to semi-static rather than dynamic.

[0165] Fig.16 is a flow chart illustrating a data transmission method according to another embodiment of the present invention.

[0166] exist Fig.16In the illustrated content, the transmitter is a terminal and the receiver is a base station. However, if the transmitter and the receiver are both terminals, the execution of repeated transmission can still be similar to this.

[0167] Reference Fig.16 The number of repeated transmissions and the maximum number of repeated transmissions may be pre-set by the base station as semi-static or static using RRC. For example, the base station may inform the terminal of the pre-repeated transmission number and / or the maximum number of repeated transmissions through an upper layer protocol signal such as RRC (S1610). That is, the value set by RRC may be the maximum number of repeated transmissions and / or the pre-repeated transmission number.

[0168] The terminal uses the first data to construct a plurality of PUSCHs based on the information of the maximum number of repeated transmissions or the number of pre-repeated transmissions (S1620). Here, the first data can be uniformly mapped to the plurality of PUSCHs. The terminal can repeatedly transmit the plurality of PUSCHs to the base station using different time and / or frequency resources (S1630).

[0169] The base station receives multiple PUSCHs from the terminal and can decode them (S1640), and can also transmit feedback (multiple ACK / NACK) of each repeated transmission (multiple PUSCHs) to the terminal. At this time, the base station determines the optimal number of repeated transmissions based on the number of ACKs and / or NACKs included in the feedback (S1660).

[0170] As an example, the base station receives multiple PUSCHs from the terminal, decodes them, and then transmits HARQ ACK for successfully received PUSCHs and transmits HARQ NACK for erroneous PUSCHs. The base station determines the number of repeated transmissions of the second data based on the channel state determined based on the PUSCHs received from the terminal, the number of transmitted HARQ ACKs, and / or the number of transmitted HARQ NACKs.

[0171] In addition, when determining whether the data needs to be retransmitted, the base station can use the CC method and / or the IR method. For example, when the base station decodes multiple PUSCHs and an error occurs on the first PUSCH, the first PUSCH can be combined with the second PUSCH, and the error generated in the first PUSCH and / or the second PUSCH can be corrected. If errors occur on multiple PUSCHs, as long as they are combined and the relevant data is successfully decoded, the base station does not transmit HARQ NACK for the last received PUSCH, but transmits HARQ ACK, thereby avoiding the terminal from unnecessary retransmission of relevant data.

[0172] The transmitter may inform the receiver of the number of repeated transmissions of the second data through control information such as DCI.

[0173] Fig.16 This is explained as an example. Although the figure shows that the number of repeated transmissions is determined by the base station, when the transmitter is a transmitting terminal and the receiver is a receiving terminal, the number of repeated transmissions can be determined by the transmitting terminal or the receiving terminal.

[0174] <CBG-based transmission method and device>

[0175] Fig.17 FIG. 1 is a diagram for explaining the concept of a code block group used in the present invention.

[0176] In the NR system, when retransmission is performed due to HARQ, it is performed in units of code block groups (CBGs) that are smaller than the transport block (TB). For example, if we refer to Fig.17 , a TB can be divided into 8 code blocks (CB), and 3 code blocks can be combined into a CBG. But this is just an example, a code block can also constitute a CBG, and a CBG can also constitute a TB.

[0177] Fig.18 FIG. 1 is a diagram illustrating a PDSCH serving cell structure applicable to an embodiment of the present invention. Fig.19 FIG. 1 is a diagram illustrating a PUSCH serving cell structure according to an embodiment of the present invention.

[0178] Reference Fig.18 and Fig.19 In the uplink and downlink transmission processes, affected by the upper protocol signals, each TB can be composed of 2, 4, 6, or 8 CBGs at most. CBG is a group of 2, 4, 6, 8, etc. code blocks bundled together, and reflected on the DCI as a unit of HARQ retransmission.

[0179] The DCI format 0_1 ​​used for PUSCH allocation is the same as the content of Table 2 below, and the DCI format 1_1 used for PDSCH allocation is the same as the content of Table 3 below.

[0180] [Table 2]

[0181]

[0182] [Table 3]

[0183]

[0184] But in general, URLLC data is smaller than eMBB data and requires low latency (Low Latency), so the unit (or size) of CBG needs to be set smaller than eMBB. Therefore, according to this embodiment, unlike the CBG for eMBB, the CBG for URLLC purposes can be set separately. As an example, the CBG for URLLC may consist of 1, 2, 3, or 4 code blocks. Alternatively, for URLLC, the maximum number of CBGs contained in a TB can be set to 4, 8, 12, or 16. That is, when the URLLC data is transmitted again, the maximum number of CBGs contained in the TB can be determined according to the size of the TB, and the size unit of the retransmitted data will eventually be smaller than the eMB.

[0185] For example, for URLLC, if the size of the TB is the same as that of eMBB, then for URLLC, the maximum number of CBGs per TB can be set to be more than that of eMBB. If the size of the TB is smaller than that of eMBB, then the maximum number of CBGs per TB on URLLC can be set to be similar to that of eMBB. According to this embodiment, the maximum number of CBGs for each TB used by URLLC can be set separately according to RRC without being affected by the maximum number of CBGs for each TB used by eMBB.

[0186] The information of the CBG used for URLLC can be indicated by the command of RRC, and the setting of DCI can be changed or additionally added to reflect the information when necessary. For example, in DCI format 0_1 ​​in Table 1 and / or DCI format 1_1 in Table 2, a field for CBG transmission information for URLLC can be added. For another example, the CBG transmission information of the URLLC is set to any one of 0, 2, 4, 6, 8, 10, 12, 14 or 16 bits, and when retransmitting URLLC data, the retransmission of the corresponding CBG can be commanded to be specified as a beat spectrum.

[0187] On the other hand, for RRC, the maximum number of CBGs per TB for URLLC can be set independently without being affected by the current maximum number of CBGs per TB for eMBB (2, 4, 6, 8). Figure 6 and / or Figure 7 In the RRC information, each TB used for URRLC can be set to the maximum number of CBGs.

[0188] In addition, the information of the number of CBs (Code Blocks Per Code Block Group for URLLC) per CBG can be increased according to {n1, n2, n4, n8}. As another example, Figure 6 and / or Figure 7 In the RRC information, the maximum number of CBGs (max Code Block Groups Per Transport Block for URLLC) for each TB can be increased according to {n4, n8, n12, n16}.

[0189] Another example is that without using RRC to set the CBG for URLLC separately, if the data is consistent with URLLC, the maximum number of CBGs for each TB (2, 4, 6, 8, 16) can be mapped separately to the table for URLLC so that it can be identified as (4, 8, 12, 16). For example, if the base station sets the number of CBGs for each TB to "2", the terminal can set the number of CBGs for each TB to "4" for URLLC data based on the information set in the ULLC table, so that only the CBGs that generate erroneous data contained in the 4 CBGs can be retransmitted.

[0190] When the above method is adopted, the time required for retransmitting URLLC data can be reduced through HARQ, which will make the retransmission of URLLC data with a smaller data size more efficient.

[0191] Fig. 20 1 is a diagram for illustrating a situation where eMBB data is retransmitted in an embodiment of the present invention. Fig.21 It is a drawing used to illustrate the situation of retransmitting URLLC data in one embodiment of the present invention.

[0192] First, refer to FIG. 20 , which illustrates a diagram in which one TB is set to two CBGs and one CBG is set to be composed of four CBs. When initially transmitting eMBB data, the transmitter transmits in TB units, and thus transmits CB#0 to CB#7 to the receiver.

[0193] In this case, when at least one error occurs on CB#0 to CB#3, that is, when the transmitter receives a HARQ NACK for at least one of CB#0 to CB#3 from the receiver, the transmitter retransmits CGB#1 including the corresponding CB. Fig.21 As shown, in Fig. 20When an erroneous CB (CB#1) is generated under the same circumstances and conforms to the URLLC data, the transmitter can generate a CBG for eMBB data that is smaller than the CGB size and retransmit it. To this end, when retransmitting URLLC data, the transmitter can increase the maximum number of CGBs per TB, thereby increasing the number of CBGs of the initially transmitted TB, or reducing the number of each CGB. Therefore, according to this embodiment, compared with the case of retransmitting eMBB data, URLLC data can be retransmitted in smaller units, so that retransmission with low latency and high efficiency can be achieved.

[0194] Fig. 22 is a flowchart illustrating a data transmission method in another embodiment of the present invention.

[0195] The following content will refer to Fig. 22 , describing the method by which the transmitter transmits data to the receiver in this embodiment. In this embodiment, if the transmitter is a base station, the receiver may be a terminal; if the transmitter is a terminal, the receiver may be a base station or other terminal. If the receiver is a base station, the above data may be referred to as URLLC data, uplink data, PUSCH or PUSCH data. If the receiver is another terminal, the above data may be referred to as URLLC data, sidelink data, PSSCH or PSSCH data. If the transmitter is a base station, the above data may be referred to as URLLC data, downlink data, PDSCH or PDSCH data.

[0196] For example, when the transmitter is a terminal and the receiver is a base station, the terminal transmits uplink data to the base station (S2210), and receives feedback of the uplink data from the base station (S2220). The feedback here can be HARQ ACK or HARQ NACK for the uplink data.

[0197] Based on the above feedback, the terminal can determine whether the above uplink data needs to be retransmitted (S2230). If the feedback of the uplink data transmitted to the base station is ACK, the terminal determines that the data transmission is successful and does not retransmit the data. That is, the relevant data will not be retransmitted. However, if the above feedback contains NACK, the terminal can retransmit the corresponding data. At this time, the terminal can adjust the CBG size of the above uplink data based on the type of uplink data that needs to be retransmitted, and retransmit it in units of the adjusted CBG. For example, when the data corresponding to NACK is eMBB data, the terminal can retransmit the CGB including the erroneous code block to the base station, such as Fig. 20 However, if the data corresponding to NACK is URLLC data, the terminal can Fig.21As shown, the size of the CBG is adjusted (S2240), and retransmission is performed based on the adjusted CGB (S2250). In this case, in order to enable URLLC data to be quickly transmitted with fewer resources, the size of the CBG of the URLLC data can be set to be smaller than the CBG size of the eMBB data. Information related to this (information about the CBG size of the URLLC data) can be received from the above-mentioned base station through at least one of RRC information and / or DCI. In this case, the code block group for retransmitting eMBB data may include 2, 4, 6 or 8 code blocks, and the code block group for retransmitting the above-mentioned URLLC data may include 1, 2, 3 or 4 code blocks.

[0198] As another example, if the transmitter is a base station and the receiver is a terminal, then after the base station receives feedback from the terminal regarding the downlink data transmitted to the terminal, it can use this as a basis to determine whether the data needs to be transmitted again. If the above feedback is ACK, the base station determines that the data transmission is successful and transmits the next data. However, if the above feedback includes NACK, the base station can adjust the size of the CBG based on the type of the corresponding data and retransmit it in units of the adjusted CBG. For example, when the data corresponding to the NACK is eMBB data, the base station can Fig. 20 As shown in FIG. 1 , the CGB including the code block in which the error occurred can be retransmitted to the terminal. However, if the data corresponding to the NACK is URLLC data, the base station can Fig.21 As shown, the size of the CBG is adjusted (S2240), and the adjusted CGB is used as the basis for retransmission (S2250). In this case, the base station can transmit information about the CBG size of the URLLC data to the terminal through DCI. Alternatively, the information about the CBG size of the above-mentioned URLLC data can be sent to the terminal in advance through RRC information. Here, the information about the CBG size of the retransmission of the above-mentioned URLLC data can be information about the maximum number of code block groups per TB of URLLC data, or it can be information that separately sets the information about the maximum number of code block groups per TB of eMBB data.

[0199] Fig.23 It is a structural framework diagram of a wireless communication system according to an embodiment of the present invention.

[0200] Reference Fig.23The terminal (2300) includes a memory (2305), a processor (2310) and an RF unit (RF, (radiofrequency) unit, 2315). The memory (2305) is connected to the processor (2310) and stores various information for driving the processor (2310). The RF unit (2315) is connected to the processor (2310) to send and / or receive wireless signals. For example, the RF unit (2315) can receive RRC information, DCI and other settings and / or control information disclosed in the present invention, downlink signals such as PDSCH, etc. from the base station (2350).

[0201] In addition, the RF unit (2315) can send uplink signals such as the CQI report and PUSCH disclosed in this specification to the base station (2350), and may or may not transmit PSSCH with other terminals (not shown).

[0202] The processor (2310) may have the functions, processes and / or methods of the terminal disclosed in the present invention. Specifically, the processor (2310) may be Figures 7 to 22 For example, the processor (2310) forms multiple PUSCHs or multiple PSSCHs according to an embodiment of the present invention, and can use Figures 7 to 23 In all embodiments of the invention, the operation of the terminal (2300) can be implemented by the processor (2310).

[0203] The memory (2305) can store the control information, setting information, etc. in the present invention, and provide the above control information, setting information, etc. to the processor (2310) according to the requirements of the processor (2310).

[0204] The base station (2350) includes a processor (2355), a memory (2360) and an RF unit (RF: radio frequency unit, 2365). The memory (2360) is connected to the processor (2355) and stores various information used to drive the processor (2355). The RF unit (2365) is connected to the processor (2355) to send and / or receive wireless signals. The processor (2355) has the functions, processes and / or methods of the base station disclosed in the present invention. In the aforementioned embodiment, the operation of the base station is implemented based on the processor (2355). The processor (2355) can generate the RRC information, downlink control information, etc. disclosed in the present invention, or can constitute multiple PDSCHs.

[0205] The processor may include an ASIC (application-specific integrated circuit), other chipsets, logic circuits and / or data processors. The memory may include ROM (read-only memory), RAM (random access memory), flash memory, memory cards, storage media and / or other storage devices. The RF unit may include a baseband circuit for processing wireless signals. When the embodiments of the present invention are implemented by software, the above techniques may be implemented by modules (processes, functions, etc.) that perform the above functions. The above modules are stored in the memory and are executed by the processor. The memory may be inside or outside the processor, and may also be connected to the processor by various well-known means.

[0206] In the above exemplary system, the related method is described based on a series of steps or a flowchart, but the present invention is not limited to the order of the steps, and some steps may be different from the above steps, or may occur simultaneously. In addition, as a practitioner in the field, the various steps presented in the sequence diagram are not absolutely exclusive, and other steps may be included, or one or more other steps may be deleted from the flowchart, which will not affect the core technical scope of the present invention and should be understood in this way.

Claims

1. A method for transmitting data by a terminal in a wireless communication system, characterized in that: include: The step of receiving setting information for adjusting the frequency hopping range from a base station; A step of receiving repetition information notifying the number of repetition transmissions of uplink data from the base station; The step of receiving downlink control information including frequency hopping information from the base station; The step of configuring a PUSCH repetition for uplink data corresponding to the number of repetition transmissions and resources for PUSCH repetition; as well as Perform frequency hopping steps in the order in which PUSCH is repeated; The step of performing the frequency hopping includes: using a plurality of RBs including a preset first preset resource block on a first PUSCH repetition, and using a plurality of RBs including a second preset RB having a certain interval with the first preset RB on a second PUSCH repetition, The certain interval between the first preset RB and the second preset RB is calculated based on the size of the bandwidth portion activated for transmission of the uplink data, The resources are configured to exclude demodulation reference signal DMRS resources of other user equipments.

2. The method for transmitting data according to claim 1, characterized in that: The downlink control information further includes: length information of the mini-slit; The PUSCH repetition is performed in the mini-slot unit.

3. The method for transmitting data according to claim 1, characterized in that: The multiple RBs including the first preset RB and the multiple RBs including the second preset RB are both frequency resources corresponding to both ends of the activated bandwidth part.

4. The method for transmitting data according to claim 1, characterized in that: Also includes: The step of transmitting channel quality information to the base station; the frequency hopping control information is determined based on the channel quality information.

5. The method for transmitting data according to claim 1, characterized in that: Also includes: Each time the PUSCH is repeated, an additional DM-RS is used separately.

6. The method for transmitting data according to claim 1, characterized in that: Also includes: The step of receiving information of a preset number of repeated transmissions of the PUSCH from the base station; The downlink control information includes: information on the difference between the preset number of repetition transmissions and the actual number of repetition transmissions of the PUSCH repetitions.

7. A terminal for transmitting data in a wireless communication system, characterized in that: include: an RF unit that receives setting information for adjusting a frequency hopping range from a base station, receives repetition information for notifying a number of repetition transmissions of uplink data from the base station, and receives downlink control information including frequency hopping information from the base station; as well as a processor, configuring a PUSCH repetition for uplink data corresponding to the number of repetition transmissions and resources for the PUSCH repetition, and performing frequency hopping in the order of the PUSCH repetitions; The processor uses, in a first PUSCH repetition, a plurality of RBs including a preset first preset resource block, and uses, in a second PUSCH repetition, a plurality of RBs including a second preset RB having a certain interval with the first preset RB, The certain interval between the first preset RB and the second preset RB is calculated based on the size of the bandwidth portion activated for transmission of the uplink data, The resources are configured to exclude demodulation reference signal DMRS resources of other user equipments.

8. The terminal for transmitting data in a wireless communication system according to claim 7, characterized in that: The downlink control information also includes: length information of the mini-slit, The PUSCH repetition is performed in the mini-slot unit.

9. The terminal for transmitting data in a wireless communication system according to claim 7, characterized in that: The multiple RBs including the first preset RB and the multiple RBs including the second preset RB are both frequency resources corresponding to both ends of the activated bandwidth part.

10. The terminal for transmitting data in a wireless communication system according to claim 7, characterized in that: The RF unit transmits channel quality information to the base station; and the frequency hopping control information is determined based on the channel quality information.

11. The terminal for transmitting data in a wireless communication system according to claim 7, characterized in that: Each time the PUSCH is repeated, an additional DM-RS is used separately.

12. The terminal for transmitting data in a wireless communication system according to claim 7, characterized in that: The RF unit includes: receiving information of a preset number of repetitions of the PUSCH from the base station, The downlink control information includes: information on the difference between the preset number of repetition transmissions and the actual number of repetition transmissions of the PUSCH repetitions.

13. A base station for receiving data in a wireless communication system, characterized in that: include: The RF unit transmits setting information for adjusting the frequency hopping range to the terminal, transmits repetition information for notifying the number of repetition transmissions of uplink data to the terminal, and transmits downlink control information including frequency hopping information to the terminal; as well as a processor that decodes a PUSCH repetition for uplink data corresponding to the number of repetition transmissions and resources used for the PUSCH repetition; Perform frequency hopping in the order in which PUSCH is repeated; The frequency hopping step includes using a plurality of RBs including a preset first preset resource block in a first PUSCH repetition, and using a plurality of RBs including a second preset RB having a certain interval with the first preset RB in a second PUSCH repetition. The certain interval between the first preset RB and the second preset RB is calculated based on the size of the bandwidth portion activated for transmission of the uplink data, The resources are configured to exclude demodulation reference signal DMRS resources of other user equipments.

14. The base station according to claim 13, characterized in that: The downlink control information also includes: length information of the mini-slit, The PUSCH repetition is performed in the mini-slot unit.

15. The base station according to claim 13, characterized in that: The multiple RBs including the first preset RB and the multiple RBs including the second preset RB are both frequency resources corresponding to both ends of the activated bandwidth part.

16. The base station according to claim 13, characterized in that: The RF unit receives channel quality information from the terminal; and the frequency hopping control information is determined based on the channel quality information.

17. The base station according to claim 13, characterized in that: Each time the PUSCH is repeated, an additional DM-RS is used separately.

18. The base station according to claim 13, characterized in that: The RF unit includes: transmitting information about the preset number of repetitions of the PUSCH to the terminal, The downlink control information includes: information on the difference between the preset number of repetition transmissions and the actual number of repetition transmissions of the PUSCH repetitions.

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