KR102161473B1 - Method for multi sTTI based scheduling for transmitting and receiving data channel in LTE and Apparatuses thereof - Google Patents

Abstract

This embodiment relates to a scheduling method for increasing the accuracy of data channel detection in order to provide a URLLC service in a 3GPP LTE/LTE-A system. In one embodiment, a terminal transmits an uplink data channel or a downlink data channel In the method of receiving, receiving information indicating repetitive transmission of an uplink data channel or a downlink data channel from a base station and receiving a downlink data channel from the base station based on information instructing repetitive transmission, or Including the step of transmitting an uplink data channel to the base station, wherein the information indicating repetitive transmission indicates information on the number of repetitive transmissions for an uplink data channel or a downlink data channel, and the repetitive transmission is in units of slots or subslots. It provides a method characterized in that it is carried out as.

Description

TECHNICAL FIELD [Method for multi sTTI based scheduling for transmitting and receiving data channel in LTE and Apparatuses thereof] for transmitting and receiving data channels in LTE

This embodiment relates to a scheduling method for increasing the accuracy of data channel detection in order to provide an ultra reliable and low latency communication for LTE (URLLC) service in a 3GPP LTE/LTE-A system.

Research and discussion for latency reduction in 3GPP LTE/LTE-Advanced systems are in progress. The main purpose of latency reduction is to standardize the operation of shorter transmission time intervals (hereinafter, may be referred to as short TTI or sTTI) in order to improve the throughput of TCP.

This short transmission time interval frame structure constitutes a frame in units of 2, 3, or 7 symbols in the existing LTE/LTE-Advanced frame structure, that is, TTI=1ms=14/12 OFDM symbols, and short transmission Data is transmitted/received based on the frame structure of time intervals to reduce delay and improve data throughput.

To this end, a discussion on the performance of short TTI is in progress, and discussions on the feasibility and performance of a TTI length between 0.5ms and one OFDM symbol, and maintaining backward compatibility are underway.

In addition, in the 3GPP LTE/LTE-Advanced system, research and discussion on URLLC for LTE, a service that provides high reliability as well as the above-described delay reduction, are being conducted. In particular, there is an increasing need to prepare a data channel transmission/reception scheme capable of providing improved reliability in URLLC for LTE.

An object of the present embodiment is to provide a method of transmitting and receiving a data channel between a terminal and a base station that satisfies an improved reliability requirement in URLLC for LTE. In particular, an object of the present embodiment is to provide a multi-TTI-based scheduling method capable of satisfying the BLER = 10 ^-5 accuracy, which is a transmission/reception request performance of a data channel in URLLC for LTE.

An embodiment devised to solve the above-described problem is a method for a terminal to transmit an uplink data channel or to receive a downlink data channel, in which the base station instructs repeated transmission of an uplink data channel or a downlink data channel. Receiving information from the base station or transmitting an uplink data channel to the base station based on the step of receiving information and information instructing repetitive transmission, but the information indicating repeated transmission is uplink data Provides a method characterized in that information on the number of repetitive transmissions for a channel or a downlink data channel is indicated, and repetitive transmission is performed in units of slots or subslots.

In addition, in an embodiment, in a method for a base station to receive an uplink data channel or transmit a downlink data channel, the steps of transmitting information indicating repetitive transmission of an uplink data channel or a downlink data channel to a terminal and repetition Including the step of receiving an uplink data channel from the terminal or transmitting a downlink data channel to the terminal based on the information instructing transmission, the information instructing the repetitive transmission is the uplink data channel or the downlink data channel. Provides a method characterized in that information on the number of repetitive transmissions is indicated, and repetitive transmission is performed in units of slots or subslots.

In addition, in an embodiment, in a terminal transmitting an uplink data channel or receiving a downlink data channel, information indicating repetitive transmission of an uplink data channel or a downlink data channel is received from a base station, and repetitive transmission is indicated. A receiving unit for receiving a downlink data channel from the base station based on the information to be transmitted and a transmitting unit for transmitting an uplink data channel to the base station based on information indicating repetitive transmission, but the information indicating repetitive transmission is an uplink data channel Alternatively, information on the number of repetitive transmissions for a downlink data channel is indicated, and repetitive transmission is performed in units of slots or subslots.

In addition, in an embodiment, in a base station receiving an uplink data channel or transmitting a downlink data channel, information indicating repetitive transmission of an uplink data channel or a downlink data channel is transmitted to a terminal, and repetitive transmission is indicated. A transmitter for transmitting the downlink data channel to the terminal based on the information, and a receiver for receiving an uplink data channel from the terminal based on information instructing repetitive transmission, wherein the information instructing repetitive transmission is uplink Provides a base station, characterized in that information on the number of repetitive transmissions for a link data channel or a downlink data channel is indicated, and repetitive transmission is performed in units of slots or subslots.

Through this embodiment, it is possible to provide a method for transmitting and receiving a data channel between a terminal and a base station that satisfies an improved reliability requirement in URLLC for LTE.

1 is a diagram showing processing delays and HARQ Round Trip Time (RTT) in a base station and a terminal.
FIG. 2 is a diagram for describing resource mapping per physical resource block (PRB) in one subframe.
3 is a conceptual diagram illustrating the definition of a search space.
4 is a conceptual diagram illustrating the definition of a common search space.
5 is a conceptual diagram illustrating the definition of a UE-specific search space.
6 is a diagram illustrating a non-slot based sTTI in downlink.
7 is a diagram illustrating a non-slot based sTTI in uplink.
8 is a diagram illustrating multiple sTTI scheduling based on a single subframe.
9 is a diagram illustrating multiple sTTI scheduling based on multiple subframes.
10 is a diagram illustrating an example of setting a non-slot based sTTI transmission interval.
11 is a diagram showing another example of setting a non-slot based sTTI transmission interval.
12 is a conceptual diagram of redundancy of a transport block (TB)/code block (CB) in LTE.
13 is a diagram illustrating an example of a method for mapping a redundancy version of a circular scheme in a non-slot based sTTI.
14 is a diagram illustrating an example of a method of mapping a circular redundancy version in a non-slot based sTTI in a multi-subframe period.
15 is a diagram illustrating an example of a method of setting a redundancy version in a single subframe unit in a slot-based sTTI.
16 is a diagram illustrating an example of a method of setting a redundancy version in units of multiple subframes in a slot-based sTTI.
17 is a diagram illustrating a method for a terminal to transmit an uplink data channel or receive a downlink data channel in this embodiment.
18 is a diagram showing a method for a base station to receive an uplink data channel or transmit a downlink data channel in this embodiment.
19 is a diagram illustrating a configuration of a base station according to the present embodiments.
20 is a diagram showing a configuration of a terminal according to the present embodiments.
21 is a diagram illustrating an example of downlink control information including information indicating repetitive transmission.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible even if they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In the present specification, a wireless communication system refers to a system for providing various communication services such as voice and packet data. The wireless communication system includes a user equipment (UE) and a base station (BS).

A user terminal is a generic concept that refers to a terminal in wireless communication, as well as UE (User Equipment) in WCDMA, LTE, HSPA, and IMT-2020 (5G or New Radio), as well as MS (Mobile Station) and UT in GSM. It should be interpreted as a concept that includes all of (User Terminal), SS (Subscriber Station), and wireless device.

A base station or cell generally refers to a station that communicates with a user terminal, and Node-B (Node-B), evolved Node-B (eNB), gNB (gNode-B), LPN (Low Power Node) ), Sector, Site, various types of antennas, BTS (Base Transceiver System), Access Point, Points (e.g., Transmit Point, Receiving Point, Transceiver Point), Relay Node ( Relay Node), mega cell, macro cell, micro cell, pico cell, femto cell, RRH (Remote Radio Head), RU (Radio Unit), small cell, etc.

In the various cells listed above, since there is a base station controlling each cell, the base station can be interpreted in two meanings. 1) In relation to the radio area, the device itself may provide a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, and a small cell, or 2) the radio area itself may be indicated. In 1), all devices that are controlled by the same entity that provide a predetermined wireless area are controlled by the same entity, or all devices that interact to form a wireless area in collaboration are instructed to the base station. Points, transmission/reception points, transmission points, reception points, etc. are an embodiment of the base station according to the configuration method of the wireless area. In 2), it is possible to instruct the base station to the radio region itself that receives or transmits a signal from the viewpoint of the user terminal or the viewpoint of a neighboring base station.

In the present specification, a cell refers to a component carrier having coverage of a signal transmitted from a transmission/reception point or a coverage of a signal transmitted from a transmission/reception point, and the transmission/reception point itself. I can.

In the present specification, the user terminal and the base station are two (Uplink or Downlink) transmission/reception subjects used to implement the technology or technical idea described in the present invention, and are used in a comprehensive sense, and are not limited by a specific term or word. Does not.

Here, the uplink (Uplink, UL, or uplink) refers to a method of transmitting and receiving data to the base station by the user terminal, and the downlink (Downlink, DL, or downlink) is transmitting and receiving data to the user terminal by the base station. It means the way to do it.

For uplink transmission and downlink transmission, a Time Division Duplex (TDD) scheme transmitted using different times may be used, and a frequency division duplex (FDD) scheme transmitted using different frequencies, a TDD scheme and an FDD scheme Mixed use methods can be used.

In addition, in a wireless communication system, a standard is configured by configuring uplink and downlink based on one carrier or carrier pair.

In the uplink and downlink, control information is transmitted through a control channel such as Physical Downlink Control CHannel (PDCCH), Physical Uplink Control CHannel (PUCCH), etc., and physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH) It is configured with the same data channel to transmit data.

Downlink may refer to a communication or communication path from multiple transmission/reception points to a terminal, and uplink may refer to a communication or communication path from a terminal to multiple transmission/reception points. In this case, in the downlink, the transmitter may be a part of the multiple transmission/reception points, and the receiver may be a part of the terminal. In addition, in the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of the multiple transmission/reception points.

Hereinafter, a situation in which signals are transmitted/received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH may be expressed in the form of “transmitting and receiving PUCCH, PUSCH, PDCCH, and PDSCH”.

Meanwhile, high layer signaling described below includes RRC signaling that transmits RRC information including RRC parameters.

The base station performs downlink transmission to the terminals. The base station is a physical downlink for transmitting downlink control information such as scheduling required for reception of a downlink data channel, which is a main physical channel for unicast transmission, and scheduling approval information for transmission in an uplink data channel. Can transmit a control channel. Hereinafter, transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

There are no restrictions on the multiple access scheme applied in the wireless communication system. Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Non-Orthogonal Multiple Access (NOMA), OFDM-TDMA, OFDM-FDMA, Various multiple access techniques such as OFDM-CDMA can be used. Here, NOMA includes Sparse Code Multiple Access (SCMA) and Low Density Spreading (LDS).

An embodiment of the present invention is used in resource allocation in asynchronous wireless communication evolving to LTE/LTE-Advanced, IMT-2020 through GSM, WCDMA, HSPA, and synchronous wireless communication field evolving to CDMA, CDMA-2000 and UMB. Can be applied.

In this specification, a machine type communication (MTC) terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. Alternatively, in this specification, the MTC terminal may mean a terminal defined as a specific category for supporting low cost (or low complexity) and/or coverage enhancement.

In other words, in this specification, the MTC terminal may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category/type that performs an LTE-based MTC-related operation. Alternatively, in this specification, the MTC terminal supports improved coverage compared to the existing LTE coverage, or the UE category/type defined in the existing 3GPP Release-12 or lower supporting low power consumption, or a newly defined Release-13 low cost (or low complexity) may mean UE category/type. Or, it may mean a further enhanced MTC terminal defined in Release-14.

In the present specification, a NB-IoT (NarrowBand Internet of Things) terminal means a terminal that supports wireless access for cellular IoT. The objectives of the NB-IoT technology include improved indoor coverage, support for large-scale low-speed terminals, low latency sensitivity, ultra-low cost terminals, low power consumption, and an optimized network structure.

As representative usage scenarios in New Radio (NR), which is currently being discussed in 3GPP, eMBB (enhanced mobile broadband), mMTC (massive machine type communication), and URLLC (Ultra Reliable and Low Latency Communication) have been proposed.

In this specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, and various messages related to NR (New Radio) Can be interpreted as a meaning used in the past or present, or in various meanings used in the future.

Latency reduction

There is a discussion on latency reduction. The main purpose of latency reduction is to standardize the operation of shorter transmission time intervals (hereinafter, referred to as'short TTI' or'sTTI') in order to improve the throughput of TCP.

Potential impacts and research are being conducted in the following range.

o Assess specification impact and study feasibility and performance of TTI when the TTI length is 0.5 ms and one OFDM symbol in consideration of the influence on the reference signal and the control signal of the physical layer. lengths between 0.5ms and one OFDM symbol, taking into account impact on reference signals and physical layer control signaling)

o It is compatible with the existing system and must support the operation of terminals prior to Rel 13 in the same carrier. (backwards compatibility shall be preserved (thus allowing normal operation of pre-Rel 13 UEs on the same carrier))

Latency reduction can be achieved by the following physical layer techniques.

-Short transmission time interval (short TTI)

-Reduced processing time in implementation

-New frame structure of TDD

In addition, the following discussions are underway on latency reduction.

■ Following design assumptions are considered:

o The short transmission time interval does not exceed the subframe interval (No shortened TTI spans over subframe boundary)

o At least for SIBs and paging, PDCCH and legacy PDSCH are used for scheduling.

■ The potential specific impacts for the followings are studied

o The UE is expected to receive the sPDSCH through at least downlink unicast. (UE is expected to receive a sPDSCH at least for downlink unicast)

■ sPDSCH refers to PDSCH carrying data in a short TTI (sPDSCH refers to PDSCH carrying data in a short TTI)

o The UE is expected to receive the PDSCH through downlink unicast. (UE is expected to receive PDSCH for downlink unicast)

■ Whether the UE can simultaneously receive sPDSCH and PDSCH through downlink unicast (whether a UE is expected to receive both sPDSCH and PDSCH for downlink unicast simultaneously)

o The number of supported short TTIs

■ Following design assumptions are used for the study.

o From the base station perspective, the existing non-sTTI and sTTI may be frequency division multiplexed in the same subframe of the same carrier. (From eNB perspective, existing non-sTTI and sTTI can be FDMed in the same subframe in the same carrier)

■ Additional research on other multiplexing method(s) with existing non-sTTI for UE supporting latency reduction features in existing non-sTTI

■ In this study, the following aspects are assumed in RAN1.

o Procedures for PSS/SSS, PBCH, PCFICH, PRACH, random access, paging, and SIB are not changed. (PSS/SSS, PBCH, PCFICH and PRACH, Random access, SIB and Paging procedures are not modified.)

■ Following aspects are further studied in the next RAN1 meeting.

o Note: But the study is not limited to them.

o Design of sPUSCH DM-RS

■ Method 1: The same DM-RS symbol is shared between several short-TTIs in the same subframe. (Alt.1: DM-RS symbol shared by multiple short-TTIs within the same subframe)

■ Scheme 2: Each sPUSCH has a DM-RS. (Alt.2: DM-RS contained in each sPUSCH)

o HARQ for sPUSCH (HARQ for sPUSCH)

■ Whether to recognize asynchronous/synchronous HARQ/how to recognize (Whether/how to realize asynchronous and/or synchronous HARQ)

o sTTI operation for Pcell and/or SCells by (e)CA in addition to non-(e)CA case in CA in addition to non-CA case

1 is a diagram for explaining processing delays and HARQ Round Trip Time (RTT) in a base station and a terminal.

Basically, in the average down-link latency calculation, the delay can be calculated according to the following procedure.

The one-way delay in the LTE user plane for the scheduled UE may consist of a fixed node processing delay and 1 TTI duration for transmission as shown in FIG. 1 below. Assuming that the processing time can be scaled by the same TTI reduction factor maintaining the same number of HARQ processes, the one-way delay can be calculated as follows: (Following the same approach as in section B.2.1 in 3GPP TR 36.912, the LTE U-plane one-way latency for a scheduled UE consists of the fixed node processing delays and 1 TTI duration for transmission, as shown in Figure A.1 below.Assuming the processing times can be scaled by the same factor of TTI reduction keeping the same number of HARQ processes, the one way latency can be calculated as)

D = 1.5 TTI (eNB processing and scheduling) + 1 TTI (transmission) + 1.5 TTI (UE processing) + n*8 TTI (HARQ retransmissions)

= (4 + n*8) TTI.

If there may be 0 or 1 retransmissions, and assuming p as the probability of an error occurring in the first transmission, the delay can be calculated as follows: (Considering a typical case where there would be 0 or 1 retransmission, and assuming error probability of the first transmission to be p, the delay is given by)

D = (4 + p*8) TTI.

So, for 0% BLER (Block Error Rate), D = 4 * TTI,

And for 10% BLER, D = 4.8 * TTI.

In UE Calculate the starting average uplink transmission delay (Average UE initiated UL transmission latency calculation)

It is assumed that the UE is in a connected state and in synchronization state and wants uplink transmission such as transmitting a TCP ACK. Table 1 discloses the steps and their contribution to uplink delay. In order to maintain consistency in comparison between downlink and uplink, the eNB adds an eNB processing delay after receiving the uplink data (Step 7) (Assume UE is in connected/synchronized mode and wants to do UL transmission, eg , to send TCP ACK.Following table shows the steps and their corresponding contribution to the UL transmission latency.To be consistent in comparison of DL and UL, we add the eNB processing delay in the UL after the UL data is received by the eNB ( step 7).)

Step Description Delay One. Average delay to next SR opportunity SR periodicity/2 2. UE sends SR 1 TTI 3. eNB decodes SR and generates scheduling grant 3 TTI 4. Transmission of scheduling grant (assumed always error free) 1 TTI 5. UE processing delay (decoding Scheduling grant + L1 encoding of data) 3 TTI 6. UE sends UL transmission (1 + p*8) TTI where p is initial BLER. 7. eNB receives and decodes the UL data 1.5 TTI

In the table above, the half delay of steps 1-4 and 5 is assumed to be due to a scheduling request, and the rest are assumed for uplink data transmission. (In the table above, steps 1-4 and half delay of step 5 is assumed to be due to SR, and rest is assumed for UL data transmission in values shown in Table 4)

Resource mapping of short TTI

In FIG. 2, when considering a control field composed of two antenna ports and two OFDM symbols, the above resource map represents the existing resource mapping of the PRB in one subframe. In FIG. 2, the following resource map is a short TTI resource mapping in consideration of a control field composed of two OFDM symbols to ensure backward compatibility. In short TTI, the loss rate at the PHY layer is assumed to be (L _legacy , eg 5%-50%). (In Figure 2, the resource map above is the legacy resource mapping per PRB in one subframe, considering 2 Antenna ports and 2 OFDM symbols control field.In Figure 2, the resource map below is the short TTI resource mapping, considering 2 OFDM symbols used for the control field in order to ensure the backward compatibility.The loss rates (L _legacy , eg 5%-50% ) of the PHY layer in short TTI duration are assumed.)

short At TTI TBS Calculation of short TTI )

According to the above-described resource mapping and transmit block size (TBS) calculation formula, the loss rate of the PHY layer for the existing PDSCH may be calculated as shown in Equation 1. (According to the resource mapping and the TBS calculation) formula given above, the loss rate of PHY layer for legacy PDSCH is calculated as follows):

For different short TTI durations, the transport block size in the PDSCH of the short TTI may be calculated as shown in Table 2. (For different short TTI duration, The TBS of short TTI PDSCH is calculated as the following table:)

TTI Duration TBS of short TTI PDSCH (TBS _short ) 7 OFDM symbol

First time slot:

Second time slot:

2 OFDM symbol

1 OFDM symbol

existing PDCCH detection

Basically, to detect the PDCCH, blind decoding is performed based on a given hashing function based on an aggregation level and a PDCCH candidate described below.

The definition of a search space using a hashing function and a procedure for performing blind decoding are as follows.

1) Definition of search space

◆ Search Space

● Variable Y _k

-For the COMMON search space

-For the UE-specific search space

◆ Size of search space

● CCE units

● The size depends on the type and aggregation level of search space.

● 4 kinds of size: 6, 8, 12, 16 [CCEs]

◆ the number of PDCCH candidates ^{M (L) (Number of PDCCH} candidates M (L))

● The set of PDCCH candidates to monitor are defined in terms of search spaces.

● Mainly connected to the aggregation level

2) Y _k Relationship between Y _k and search space

■ Offset of starting-point of search space

■ Offset is a terminal-specific value within a terminal-specific search space (Offset(Y _k ) has UE-specific value within UE-specific search space)

■ Offset is fixed to 0 within the common search space (Offset(Y _k ) is fixed by zero in common search space)

■ Example: Common Search Space

-Aggregation level (L): 4, N _CCE = 35

-Size of Search space: 16 CCEs

-Number of candidates (M ^(L) ): 4

- _k = Y 0 (Y _k will not be affected to _{n RNTI (Y k does not get} affected by n RNTI))

■ Example: UE- specific Search Space

-Aggregation level (L): 4, N _CCE = 35

-Size of Search space: 8 CCEs

-Number of candidates (M ^(L) ): 2

Eventually, based on the defined search space, the maximum number of blind decoding for the UE to search for its own PDCCH is determined as shown in Table 4 below.

That is, for all aggregation levels 1,2, 4, and 8, PDCCH candidates are UESS=16 and CSS=6. Therefore, since there are two PDCCH formats to be found in each transmission mode as DCI format 1A + α', the total number of blind decoding is 44 (based on Legacy PDCCH. ).

In LTE URLLC support( URLLC support for LTE )

The main purpose of URLLC for LTE (Ultra reliable and low latency communication for LTE) is to introduce a URLLC service that improves reliability as well as reducing delay in LTE. Discussion and studies on potential impacts related to RAN1 are in progress within the range described below.

URLLC for LTE may be referred to as LTE URLLC, HRLLC, and the like, and its meaning is not limited by the name.

Phase 1

* Identify improved communication reliability and different latency constraints combinations for both wide and local area deployments

o Consider the ITU IMT-2020 and the 3GPP TR 38.913 requirements on URLLC and the ability to enable networks with various reliability targets and latency constraints. and the ability to enable the network to operation with a range of reliability targets and latency constraints.)

* Identify any potential new evaluations scenarios

Currently, scenarios and target targets for new standard items for URLLC for LTE are being discussed. Specifically, a method of improving the accuracy of data channel transmission and reception in URLLC for LTE is being discussed.

In this case, the meaning that the data channel is transmitted/received means that the terminal transmits an uplink data channel to the base station or the base station transmits a downlink data channel to the terminal.

In a frame structure with a short transmission time interval (hereinafter, may be referred to as short TTI or sTTI), the downlink data channel may be a downlink data channel (sPDSCH) with a short transmission time interval. In addition, in the frame structure of the short transmission time interval, the uplink data channel may be an uplink data channel (sPUSCH) of the short transmission time interval.

In the embodiments described below, a data channel transmission/reception method capable of satisfying an improved reliability requirement in URLLC for LTE will be described. In particular, a multi-TTI scheduling scheme to satisfy the BLER = 10 ^-5 accuracy required for the data channel is described.

Basically, in LTE URLLC, the existing sTTI structure is reused to satisfy the latency requirement and at the same time improve performance. Therefore, it is expected that the reliability of data channel transmission/reception can be improved through multiple sTTI scheduling through combination with a redundancy version (RV) during such sTTI transmission.

In the embodiment described below, a multi-TTI-based scheduling scheme when transmitting and receiving a data channel in URLLC for LTE is described. First, in URLLC for LTE, it is expected that scheduling will be performed based on the sTTI described above. There are a total of two basic sTTI structures to date.

● Slot-based sTTI: 0.5ms unit (slot unit)

● Non-slot based sTTI: 0.214/0.143ms unit

The aforementioned non-slot-based sTTI means that the sTTI can be a sub-slot that is a smaller unit than a slot. In LTE, since one slot may consist of 7 symbols, a subslot may consist of less than 7 symbols.

The symbol described in this embodiment means an OFDM symbol, and the symbol may be an RS symbol or a data symbol. The data symbol refers to an OFDM symbol that stores information.

For example, a non-slot based sTTI may be composed of two or three symbols, and has a structure that maintains a slot boundary of each subframe.

Keeping the slot boundary of each subframe means that there is no sTTI that exists over two different slot regions. That is, the last symbol of slot #0 and the first symbol of slot #1 constituting one subframe belong to different sTTIs, and cannot belong to the same sTTI.

For example, in a 2-symbol sTTI structure, an uplink sTTI may exist as shown in FIG. 6 and a downlink sTTI may exist as shown in FIG. 7. 6 is a diagram showing a non-slot-based sTTI in downlink, and FIG. 7 is a diagram showing a non-slot-based sTTI in uplink. 6 and 7, it can be seen that sTTIs are distinguished from each other at a slot boundary, and sTTIs spanning the slot boundary do not exist.

Basically, the legacy PDCCH was designed based on the BLER accuracy of 10 ^-3 . In addition, the data channel is operated based on HARQ retransmission based on a BLER of 10 ^-1 . Here, basically, URLLC for LTE (Ultra-Reliable and Low-Latency Communications for LTE) can be considered as a main feature that enhancement is made based on the aforementioned sTTI frame structure or sTTI service.

Therefore, it can be assumed that the latency issue has already been solved by using sTTI, but the problem of satisfying the BLER accuracy condition of 10 ^-5 remains. The application range may vary depending on the size of the data, but in order to satisfy the BLER of at least 10 ^-5 accuracy of data channel transmission and reception, a multi-slot/non-slot based scheduling function must be provided.

Basically, since the UL asynchronous HARQ (UL asynchronous HARQ) structure is introduced in the sTTI structure, information on the HARQ process number/redundancy version is stored in the uplink/downlink (UL/DL) DCI. Each will be included.

However, in the current multi-slot/non-slot-based based scheduling, there is no specific discussion on setting redundancy version information.

Therefore, for this purpose, a method of scheduling transmission and reception of multiple sTTI-based data channels and a method of setting and signaling a redundancy version for repetitive data channel transmission will be described with reference to the following embodiments.

The embodiments described below may be used individually or in any combination.

Example One. URLLC Multi-slot/non-slot based on a single subframe unit in service sTTI Perform scheduling

In this embodiment, a method of setting a repetitive transmission unit for URLLC service in LTE based on a single subframe is proposed. Basically, two sTTI structures can be applied to a legacy subframe (=1ms), and the structures are as follows.

● Slot based sTTI: 2 sTTIs within 1ms subframe (2 sTTIs within 1ms subframe)

● Non-slot based sTTI: 6 sTTIs within 1ms subframe (6 sTTIs within 1ms subframe)

At this time, in order to satisfy the URLLC requirement of 10 ^-5 BLER, the UE or the base station performs sTTI repetitive transmission when transmitting and receiving a data channel, and this means that the criterion of the repetitive transmission is a legacy subframe unit. Accordingly, the unit of repetitive transmission may be up to 2 or 6 sTTIs in a legacy subframe according to each sTTI structure.

That is, this embodiment describes a case where a unit for performing repetitive transmission is a subframe.

First, in a slot-based sTTI, since only two sTTIs exist within a 1ms subframe, it is not necessary to divide the boundaries of a single subframe during repeated transmission.

However, in a non-slot based sTTI, 6 sTTIs may exist within a 1ms subframe. In this case, assuming that scheduling is performed continuously for 4 sTTIs in a non-slot based sTTI, the configuration is valid only within a single subframe, and the configuration for the next subframe must be received again. Means that.

For example, as shown in FIG. 8, four sTTIs from sTTI1 to sTTI4 may be set in subframe #0, and a total of three sTTIs from sTTI0 to sTTI2 may be set in subframe #1. That is, in setting a section in which repetitive transmission is performed, it can be seen that the continuous scheduling section can be effectively set in units of subframes.

In a manner similar to the above-described method, multiple sTTI settings set in units of a single subframe may be set to be repeated during a predetermined subframe period.

For example, referring to FIG. 9, it can be seen that multiple sTTI intervals in Subframe #0 and Subframe #1 are identical to each other from sTTI1 to sTTI4. In the present embodiment, description is made based on sTTI configuration for repetitive transmission interval configuration, but general multiple sTTI scheduling in which general data can be individually allocated for each sTTI may be applied in the same manner.

Example 1-1. Actual data transmission is performed within a unit subframe sTTI About setting information To the terminal Signaling box .

In non-slot based sTTI repetition transmission, repetitive transmission may be performed through up to 6 sTTIs in a subframe. In this case, in setting the multiple sTTI interval in which repetitive transmission is performed, it is not always necessary to set all sTTIs in the subframe as repetitive transmission intervals.

That is, only a section in which data transmission is actually performed may be set as a repetitive transmission section. Basically, it is most preferable to repeat such a period in units of subframes, but the base station may set a multi-subframe period according to circumstances and signal a period in which actual transmission is performed to the terminal in the period. However, in this case, there is a disadvantage of increasing overhead due to signaling.

In order to set a subframe section in which multiple sTTI transmission is performed, information such as a start subframe and a section may be set through RRC signaling.

An embodiment of transmitting sTTI set information in which actual data transmission is performed can be divided into two embodiments as follows.

Example 1-1-1. Start within unit subframe with sTTI Length information To the terminal Signaling box .

In this embodiment, when contiguous sTTI is allocated to a terminal, information on a start position of the allocated sTTI and contiguous sTTI length information is transmitted. In an alternative to signaling to be described later (Alt, alternative), DCI means dynamic signaling, and RRC means higher layer signaling (which may also be referred to as high layer signaling or semi-static signaling).

In this embodiment, the start position and the sTTI continuous transmission interval are defined as length information. Therefore, there are four alternatives according to the path through which each information is transmitted.

● Alt. 1: start position (DCI), length (RRC)

● Alt. 2: Start position (RRC), length (DCI)

● Alt. 3: Start position (DCI), length (DCI)

● Alt. 4: Start position (RRC), length (RRC)

For example, if the starting position is the sTTI index 2 (assuming that it starts from index 0) and the length is 3, the sTTI transmission period as shown in FIG. 10 may be set. That is, since the index of the start sTTI is 2, sTTI2, sTTI3, and sTTI4 are continuous transmission intervals. In this embodiment, a field of up to 3 bits may be required to indicate the start position, and a field of up to 3 bits may be required to indicate length information.

Example 1-1-2. Actual in unit subframe sTTI Transfer takes place sTTI Signals set information to the terminal.

For data transmission, it is possible to allocate not only continuous sTTI but also non-contiguous multiple sTTIs to the terminal. For this, basically, a 2-bit field is required in a slot-based sTTI structure and a 6-bit field is required in a non-slot based sTTI.

Through this, sTTI information actually transmitted can be instructed to the terminal in an on/off form for each sTTI. That is, in this embodiment, unlike the above-described embodiment 1-1-1, it is easy to set a non-continuous sTTI section.

For example, when the sTTI transmission interval is set for sTTI index = 1, 3, 5 (assuming that the index starts from 0) as shown in FIG. 11, the signaling information is '010101' (this embodiment Signaling information of up to 6 bits may be required.)

Meanwhile, as a method of performing signaling, dynamic signaling in which a corresponding field is directly added in DCI or semi-static signaling indicated through RRC may be used.

Example 2. Multiple subframe units sTTI Redundancy Set the redundancy version application pattern.

In this embodiment, it is assumed that an sTTI interval for repeatedly transmitting an sPDSCH is set. In addition, as described above, the method described in this embodiment may be applied in units of a single subframe, and may be applied in the same manner even when the UE repeatedly transmits the sPUSCH to the base station in addition to the sPDSCH.

In this embodiment, a method of specifically setting a redundancy version for data of sPDSCH that is repeatedly transmitted through multiple sTTIs during repeated transmission will be described.

Here, the redundancy version refers to a transmission position of a block encoded in units of a transport block (TB)/code block (CB) to be transmitted through the sPDSCH.

Referring to FIG. 12, it can be seen that data transmission locations are different for each redundancy version. Therefore, when transmitting data through multiple sTTIs, it is important to transmit data by selecting a redundancy version. Finally, the terminal or the base station may perform soft value combining on data transmission.

Basically, a pattern of a redundancy version may be set based on a single subframe period. Hereinafter, a specific value that determines the transmission position of each sTTI is referred to as a redundancy version pattern, and when data is transmitted through one or more sTTIs, a sequence of the redundancy version pattern is referred to as a redundancy version sequence.

Basically, there can be a total of 4 patterns in the redundancy version (Rv=0,1,2,3 exists).

In a slot-based sTTI, since only two sTTIs exist in a 1 ms subframe, the length of the base sequence is 2, and there may be sequences for a total of 4 redundancy versions.

On the other hand, in a non-slot based sTTI, a total of 6 sTTIs may exist in a subframe, but a total of 4 patterns of the redundancy version provided by default (Rv=0,1,2, 3 exists), so the default sequence length for the redundancy version is 4.

In this case, a method of setting the redundancy version may be determined as follows, for example.

1) Slot-based scheduling: RV(rv ₀ ,rv ₁ ) = {(0,2), (1,3), (2,0), (3,1)} total of 4 sequences Exist (select and set)

2) Non-slot-based scheduling: RV(rv ₀ , rv ₁ , rv ₂ , rv ₃ ) can be set as follows.

A. Alt 1: Apply RV(rv ₀ , rv ₁ , rv ₂ , rv ₃ )=(0,2,1,3) on a modulo basis

B. Alt 2: RV(rv ₀ , rv ₁ , rv ₂ , rv ₃ )=(0,0,0,0),(1,1,1,1),(2,2,2,2) or Apply (3,3,3,3) based on modulo

C. Alt 3: RV(rv ₀ , rv ₁ , rv ₂ , rv ₃ )=(2,2,1,1) or (1,1,3,3), etc. modulo) based

In non-slot based sTTI repetitive transmission, repetitive transmission through up to 6 sTTIs is possible within one subframe. According to the number of transmissions of each of these sPDSCHs, a circular modulo 4 method may be applied.

For example, it is defined as RV(rv ₀ , rv ₁ ,rv ₂ , rv ₃ )=(0,2,1,3), and it is assumed that 6 non-slot based sTTI repetitive transmissions are performed. do. Assuming that the transmitted sPDSCH/PDSCH is sequentially transmitted, the sequence of the redundancy version is RV(rv ₀ , rv ₁ , rv ₂ , rv _{3 ,} rv ₀ , rv _{1 ,} )=(0,2,1,3,0 Becomes ,2).

In this case, it is confirmed that the sequence of the redundancy version consists of 6 elements, the pattern of the first element and the pattern of the 5th element of the sequence are the same as 0, and the pattern of the second element and the pattern of the 6th element of the sequence are the same as 2. I can.

As another example, assuming that RV(rv ₀ , rv ₁ , rv ₂ , rv ₃ ) = (0,2,3,1) is defined, and 6 non-slot based sTTI repetitive transmissions are performed , The sequence of the redundancy version becomes RV(rv ₀ , rv ₁ , rv ₂ , rv _3, rv ₀ , rv _1, )=(0,2,3,1,0,2).

13 shows a redundancy version mapping method applied when transmitting such sTTI-based data. Meanwhile, in the multiple subframe period, a sequence of a redundancy version is repeated as shown in FIG. 14. The sequence of the redundancy version applied in FIGS. 13 and 14 is RV(rv ₀ , rv ₁ , rv ₂ , rv _3, rv ₀ , rv _1, )=(0,2,1,3,0,2).

Example 2-1. Multiple subframe units sTTI Redundancy version application pattern is set.

This embodiment uses the same method as the above-described embodiment 2, but describes a case where the section unit in which the setting is performed is the multi-subframe section unit.

For example, it is assumed that RV(rv ₀ , rv ₁ , rv ₂ , rv ₃ ) = (0,2,1,3) is applied to all sTTI continuous transmissions.

If a redundancy version is applied in a single subframe unit in a slot-based structure, a specific pattern may be repeated for two sTTI transmissions in two consecutive subframe intervals as shown in FIG. 15.

However, when a redundancy version is applied to the entire multi-subframe period, as shown in FIG. 16, the entire redundancy version may be mapped in a circular form in the entire subframe period.

In the same way, a redundancy version can be applied in the same way in a non-slot based sTTI.

17 is a diagram illustrating a method for a terminal to transmit an uplink data channel or receive a downlink data channel in this embodiment.

Referring to FIG. 17, the terminal may receive information indicating repetitive transmission of an uplink data channel or a downlink data channel from a base station (S1700).

In this case, the terminal may be a URLLC terminal supporting the above-described URLLC service.

The information indicating repetitive transmission received from the base station by the UE may indicate information on the number of repetitive transmissions for an uplink data channel or a downlink data channel.

The number of repetitive transmissions indicated by the information indicative of the above-described repetitive transmission may be determined as one of 1,2, 3, 4 and 6. For example, the number of repeated transmissions indicated by the information indicative of the above-described repeated transmission may be 3 or 6.

As an example of a method for the terminal to receive information indicating repetitive transmission from the base station, the terminal may receive information instructing repetitive transmission from the base station through downlink control information (DCI). If there is a field indicating repetitive transmission inside the DCI, the terminal may determine the number of repetitive transmissions by looking at a value for the field in the received DCI.

An example of a specific DCI configuration will be described in detail with reference to FIG. 21 to be described later.

As another example of a method for the terminal to receive information indicating repetitive transmission from the base station, the terminal may receive information instructing repetitive transmission from the base station through semi-persistent scheduling (SPS) configuration information. . In this case, the terminal may determine the number of repetitive transmissions based on the SPS periodicity indicated by the SPS configuration information.

In this case, a maximum value of the number of repetitive transmissions indicated by the information indicative of the aforementioned repetitive transmission may be 6. In addition, the maximum value of the number of repetitive transmissions may be indicated to the terminal through separate upper layer signaling (e.g. RRC signaling).

As an example, when the terminal receives information indicating repetitive transmission from the base station through DCI, when the value of the field indicating repetitive transmission inside the DCI indicates the maximum value of the number of repetitions (e.g., '11' ) Information on the maximum value (for example, 4, 6) of the specific number of repeated transmissions may be separately received from the base station through RRC signaling.

In addition, the aforementioned repetitive transmission may be performed in units of slots or subslots. In this case, the subslot means that the sTTI may be configured in a unit smaller than that of the slot, as described above, and as an example, it may be configured with 2 or 3 symbols.

In addition, the terminal may receive a downlink data channel from the base station or transmit an uplink data channel to the base station based on information indicating repetitive transmission received in step S1700 (S1710).

Meanwhile, as described in Embodiment 2, a sequence of a redundancy version for repetitive transmission may be determined. The number of elements constituting the sequence of the redundancy version may be determined according to the number of repeated transmissions.

For example, when the number of repeated transmissions is 6, the number of elements constituting the sequence of the redundancy version may also be 6. In this case, since each element may be set to one of four patterns, patterns between specific elements may be the same.

If the circular modulo 4 method described in Example 2 is applied, the pattern of the first element constituting the sequence of the redundancy version and the pattern of the fifth element are the same, and the pattern of the second element constituting the sequence of the redundancy version is the same. The pattern of the elements becomes the same.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 2, 3, 1}, the sequence of the redundancy version is {0, 2, 3, 1, 0, 2}.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 0, 0, 0}, the sequence of the redundancy version is {0, 0, 0, 0, 0, 0}.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 3, 0, 3}, the sequence of the redundancy version is {0, 3, 0, 3, 0, 3}.

18 is a diagram showing a method for a base station to receive an uplink data channel or transmit a downlink data channel in this embodiment.

Referring to FIG. 18, the base station may transmit information indicating repetitive transmission of an uplink data channel or a downlink data channel to a terminal (S1800).

In this case, the terminal may be a URLLC terminal supporting the above-described URLLC service.

The information indicating repetitive transmission transmitted from the base station to the terminal may indicate information on the number of repetitive transmissions for an uplink data channel or a downlink data channel.

The number of repetitive transmissions indicated by the information indicative of the above-described repetitive transmission may be determined as one of 1,2, 3, 4 and 6. For example, the number of repeated transmissions indicated by the information indicative of the above-described repeated transmission may be 3 or 6.

As an example of a method for the base station to transmit information instructing repetitive transmission to the terminal, the base station may transmit information instructing repetitive transmission to the terminal through DCI. If there is a field indicating repetitive transmission inside the DCI, the terminal may determine the number of repetitive transmissions by looking at a value for the field in the received DCI.

As another example of a method for the base station to transmit information indicating repetitive transmission to the terminal, the base station may transmit information instructing repetitive transmission to the terminal through semi-persistent scheduling (SPS) configuration information. In this case, the terminal may determine the number of repetitive transmissions based on the SPS periodicity indicated by the SPS configuration information.

In this case, a maximum value of the number of repetitive transmissions indicated by the information indicative of the aforementioned repetitive transmission may be 6. In addition, the maximum value of the number of repetitive transmissions may be indicated to the terminal through separate upper layer signaling (e.g. RRC signaling).

For example, when the base station transmits information indicating repetitive transmission from the base station through DCI, when the value of the field indicating repetitive transmission in the DCI indicates the maximum value of the number of repetitions (for example, '11' ) Information on the maximum value (for example, 4, 6) of the specific number of repeated transmissions may be separately transmitted to the terminal through RRC signaling.

In addition, the aforementioned repetitive transmission may be performed in units of slots or subslots. In this case, the subslot means that the sTTI may be configured in a unit smaller than that of the slot, as described above, and as an example, it may be configured with 2 or 3 symbols.

In addition, the base station may transmit a downlink data channel to the terminal or receive an uplink data channel from the terminal based on the information indicating repetitive transmission transmitted in step S1800 (S1810).

Meanwhile, as described in Embodiment 2, a sequence of a redundancy version for repetitive transmission may be determined. The number of elements constituting the sequence of the redundancy version may be determined according to the number of repeated transmissions.

For example, when the number of repeated transmissions is 6, the number of elements constituting the sequence of the redundancy version may also be 6. In this case, since each element may be set to one of four patterns, patterns between specific elements may be the same.

If the circular modulo 4 method described in Example 2 is applied, the pattern of the first element constituting the sequence of the redundancy version and the pattern of the fifth element are the same, and the pattern of the second element constituting the sequence of the redundancy version is the same. The pattern of the elements becomes the same.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 2, 3, 1}, the sequence of the redundancy version is {0, 2, 3, 1, 0, 2}.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 0, 0, 0}, the sequence of the redundancy version is {0, 0, 0, 0, 0, 0}.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 3, 0, 3}, the sequence of the redundancy version is {0, 3, 0, 3, 0, 3}.

19 is a diagram illustrating a configuration of a base station according to the present embodiments.

Referring to FIG. 19, a base station 1900 includes a control unit 1910, a transmission unit 1920, and a reception unit 1930.

The controller 1910 may control the overall operation of the base station 1910 for the base station to receive an uplink data channel or transmit a downlink data channel.

The transmitting unit 1920 and the receiving unit 1930 are used to transmit and receive signals, messages, and data necessary for carrying out the above-described present invention with a terminal.

Specifically, the transmitter 1920 transmits information indicating repetitive transmission of the uplink data channel or downlink data channel to the terminal, and transmits the downlink data channel to the terminal based on the information instructing the above-described repetition transmission. I can.

In addition, the receiver 1930 may receive an uplink data channel from the terminal based on the information instructing the above-described repetitive transmission.

In this case, the terminal may be a URLLC terminal supporting the above-described URLLC service.

The information indicating repetitive transmission transmitted from the base station to the terminal may indicate information on the number of repetitive transmissions for an uplink data channel or a downlink data channel.

The number of repetitive transmissions indicated by the information indicative of the above-described repetitive transmission may be determined as one of 1,2, 3, 4 and 6. For example, the number of repeated transmissions indicated by the information indicative of the above-described repeated transmission may be 3 or 6.

As an example of a method for the base station to transmit information instructing repetitive transmission to the terminal, the base station may transmit information instructing repetitive transmission to the terminal through DCI. If there is a field indicating repetitive transmission inside the DCI, the terminal may determine the number of repetitive transmissions by looking at a value for the field in the received DCI.

As another example of a method for the base station to receive information indicating repeated transmission to the terminal, the base station may transmit information indicating repeated transmission to the terminal through semi-persistent scheduling (SPS) configuration information. In this case, the terminal may determine the number of repetitive transmissions based on the SPS periodicity indicated by the SPS configuration information.

In this case, a maximum value of the number of repetitive transmissions indicated by the information indicative of the aforementioned repetitive transmission may be 6. In addition, the maximum value of the number of repetitive transmissions may be indicated to the terminal through separate upper layer signaling (e.g. RRC signaling).

For example, when the base station transmits information indicating repetitive transmission from the base station through DCI, when the value of the field indicating repetitive transmission in the DCI indicates the maximum value of the number of repetitions (for example, '11' ) Information on the maximum value (for example, 4, 6) of the specific number of repeated transmissions may be separately transmitted to the terminal through RRC signaling.

In addition, the aforementioned repetitive transmission may be performed in units of slots or subslots. In this case, the subslot means that the sTTI may be configured in a unit smaller than that of the slot, as described above, and as an example, it may be configured with 2 or 3 symbols.

Meanwhile, as described in Embodiment 2, a sequence of a redundancy version for repetitive transmission may be determined. The number of elements constituting the sequence of the redundancy version may be determined according to the number of repeated transmissions.

For example, when the number of repeated transmissions is 6, the number of elements constituting the sequence of the redundancy version may also be 6. In this case, since each element may be set to one of four patterns, patterns between specific elements may be the same.

If the circular modulo 4 method described in Example 2 is applied, the pattern of the first element constituting the sequence of the redundancy version and the pattern of the fifth element are the same, and the pattern of the second element constituting the sequence of the redundancy version is the same. The pattern of the elements becomes the same.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 2, 3, 1}, the sequence of the redundancy version is {0, 2, 3, 1, 0, 2}.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 0, 0, 0}, the sequence of the redundancy version is {0, 0, 0, 0, 0, 0}.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 3, 0, 3}, the sequence of the redundancy version is {0, 3, 0, 3, 0, 3}.

20 is a diagram showing a configuration of a terminal according to the present embodiments.

Referring to FIG. 20, the terminal 2000 includes a reception unit 2010, a control unit 2020, and a transmission unit 2030.

The reception unit 2010 may receive information indicating repetitive transmission of an uplink data channel or a downlink data channel from the base station, and receive a downlink data channel from the base station based on the information instructing the aforementioned repetition transmission. .

The transmitter 2030 may transmit an uplink data channel to the base station based on the information instructing the above-described repetitive transmission.

In this case, the terminal may be a URLLC terminal supporting the above-described URLLC service.

The information indicating repetitive transmission received from the base station by the UE may indicate information on the number of repetitive transmissions for an uplink data channel or a downlink data channel.

The number of repetitive transmissions indicated by the information indicative of the above-described repetitive transmission may be determined as one of 1,2, 3, 4 and 6. For example, the number of repeated transmissions indicated by the information indicative of the above-described repeated transmission may be 3 or 6.

As an example of a method for the terminal to receive information indicating repetitive transmission from the base station, the terminal may receive information instructing repetitive transmission from the base station through DCI. If there is a field indicating repetitive transmission inside the DCI, the terminal may determine the number of repetitive transmissions by looking at a value for the field in the received DCI.

As another example of a method for the terminal to receive information indicating repetitive transmission from the base station, the terminal may receive information instructing repetitive transmission from the base station through semi-persistent scheduling (SPS) configuration information. . In this case, the terminal may determine the number of repetitive transmissions based on the SPS periodicity indicated by the SPS configuration information.

In this case, a maximum value of the number of repetitive transmissions indicated by the information indicative of the aforementioned repetitive transmission may be 6. In addition, the maximum value of the number of repetitive transmissions may be indicated to the terminal through separate upper layer signaling (e.g. RRC signaling).

As an example, when the terminal receives information indicating repetitive transmission from the base station through DCI, when the value of the field indicating repetitive transmission inside the DCI indicates the maximum value of the number of repetitions (e.g., '11' ) Information on the maximum value (for example, 4, 6) of the specific number of repeated transmissions may be separately received from the base station through RRC signaling.

In addition, the aforementioned repetitive transmission may be performed in units of slots or subslots. In this case, the subslot means that the sTTI may be configured in a unit smaller than that of the slot, as described above, and as an example, it may be configured with 2 or 3 symbols.

Meanwhile, as described in Embodiment 2, a sequence of a redundancy version for repetitive transmission may be determined. The number of elements constituting the sequence of the redundancy version may be determined according to the number of repeated transmissions.

For example, when the number of repeated transmissions is 6, the number of elements constituting the sequence of the redundancy version may also be 6. In this case, since each element may be set to one of four patterns, patterns between specific elements may be the same.

If the circular modulo 4 method described in Example 2 is applied, the pattern of the first element constituting the sequence of the redundancy version and the pattern of the fifth element are the same, and the pattern of the second element constituting the sequence of the redundancy version is the same. The pattern of the elements becomes the same.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 2, 3, 1}, the sequence of the redundancy version is {0, 2, 3, 1, 0, 2}.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 0, 0, 0}, the sequence of the redundancy version is {0, 0, 0, 0, 0, 0}.

If basic sequence information RV(rv0, rv1, rv2, rv3) = {0, 3, 0, 3}, the sequence of the redundancy version is {0, 3, 0, 3, 0, 3}.

21 is a diagram illustrating an example of downlink control information including information indicating repetitive transmission.

Referring to FIG. 21, the downlink control information may include information indicating the number of repetitive transmissions. The information indicating the number of repetitive transmissions indicates how many slots or subslots of data having the same content are repeatedly transmitted when data channel transmission is performed.

At this time, since the size of the field indicating the number of repetitive transmissions in the downlink control information is limited (for example, 2 bits), the number of cases of the number of repetitive transmissions that the field indicating the number of repetition transmissions can indicate For example, in the case of 2 bits, there may be more (for example, 5) the number of possible repetitive transmissions than 4). In this case, a specific value of the number of repeated transmissions corresponding to information indicating the number of repeated transmissions may be indicated through a separate higher layer signaling (e.g. RRC signaling).

For example, assume that the size of a field indicating the number of repetitive transmissions is 2 bits, and the actual number of repetitive transmissions is one of 1,2, 3, 4, and 6. In this case, when the field indicating the number of repetitive transmissions is a specific value (for example, '11'), what is the specific value of the number of repeated transmissions indicated by the value (for example, one of 4 and 6) is separate. It can be indicated through RRC signaling.

The standard contents or standard documents mentioned in the above-described embodiments are omitted to simplify the description of the specification and constitute a part of the specification. Accordingly, it should be construed as falling within the scope of the present invention to add the contents of the standard contents and some of the standard documents to the present specification or to describe in the claims.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (24)

In a method for a terminal to transmit an uplink data channel or to receive a downlink data channel,
Receiving information indicating repeated transmission of the uplink data channel or the downlink data channel from a base station; And
Receiving the downlink data channel from the base station or transmitting the uplink data channel to the base station based on the information instructing the repetitive transmission,
Information indicating the repeated transmission,
Indicate information on the number of repetitive transmissions for the uplink data channel or the downlink data channel,
Information on the number of repeated transmissions,
Indicated by a value of a field indicating repetitive transmission consisting of 2 bits in the downlink control information, and when the value of the field is the maximum value, it is determined according to a value configured through higher layer signaling,
The repeated transmission,
A method characterized in that it is performed in units of slots or subslots. The method of claim 1,
The method, characterized in that the subslot is composed of two or three symbols. The method of claim 1,
The method according to claim 1, wherein the maximum value of the number of repeated transmissions that the information indicating the repeated transmission can indicate is 6. The method of claim 1,
The method according to claim 1, wherein the number of repetitive transmissions is 3 or 6. The method of claim 1,
The method of claim 1, wherein the sequence of redundancy versions (RVs) for repetitive transmission consists of six elements. The method of claim 5,
Each element of the sequence is set to one of four patterns,
And the pattern of the first element and the pattern of the fifth element of the sequence are the same, and the pattern of the second element and the pattern of the sixth element of the sequence are the same. In a method for a base station to receive an uplink data channel or transmit a downlink data channel,
Transmitting information indicating repetitive transmission of the uplink data channel or the downlink data channel to a terminal; And
Receiving the uplink data channel from the terminal or transmitting the downlink data channel to the terminal based on the information instructing the repetitive transmission,
Information indicating the repeated transmission,
Indicate information on the number of repetitive transmissions for the uplink data channel or the downlink data channel,
Information on the number of repeated transmissions,
Indicated by a value of a field indicating repetitive transmission consisting of 2 bits in the downlink control information, and when the value of the field is the maximum value, it is determined according to a value configured through higher layer signaling,
The repeated transmission,
A method characterized in that it is performed in units of slots or subslots. The method of claim 7,
The method, characterized in that the subslot is composed of two or three symbols. The method of claim 7,
The method according to claim 1, wherein the maximum value of the number of repeated transmissions that the information indicating the repeated transmission can indicate is 6. The method of claim 7,
The method according to claim 1, wherein the number of repetitive transmissions is 3 or 6. The method of claim 7,
The method of claim 1, wherein the sequence of redundancy versions (RVs) for repetitive transmission consists of six elements. The method of claim 11,
Each element of the sequence is set to one of four patterns,
And the pattern of the first element and the pattern of the fifth element of the sequence are the same, and the pattern of the second element and the pattern of the sixth element of the sequence are the same. In a terminal transmitting an uplink data channel or receiving a downlink data channel,
A receiving unit for receiving information indicating repetitive transmission of the uplink data channel or downlink data channel from a base station, and receiving the downlink data channel from the base station based on the information instructing the repetitive transmission; And
Including a transmitter for transmitting the uplink data channel to the base station on the basis of the information indicating the repeated transmission,
Information indicating the repeated transmission,
Indicate information on the number of repetitive transmissions for the uplink data channel or the downlink data channel,
Information on the number of repeated transmissions,
Indicated by a value of a field indicating repetitive transmission consisting of 2 bits in the downlink control information, and when the value of the field is the maximum value, it is determined according to a value configured through higher layer signaling,
The repeated transmission,
A terminal, characterized in that it is performed in a slot or subslot unit. The method of claim 13,
The terminal, characterized in that the subslot is composed of two or three symbols. The method of claim 13,
The terminal, characterized in that the maximum value of the number of repetitive transmissions indicated by the information indicating repetitive transmission is 6. The method of claim 13,
The terminal, characterized in that the number of repeated transmission is 3 or 6. The method of claim 13,
The terminal, characterized in that the sequence of the redundancy version (RV) for repetitive transmission consists of six elements. The method of claim 17,
Each element of the sequence is set to one of four patterns,
The terminal, characterized in that the pattern of the first element and the pattern of the fifth element of the sequence are the same, and the pattern of the second element and the pattern of the sixth element of the sequence are the same. In the base station receiving an uplink data channel or transmitting a downlink data channel,
A transmitter for transmitting information instructing repetitive transmission of the uplink data channel or downlink data channel to a terminal, and transmitting the downlink data channel to the terminal based on the information instructing the repetitive transmission; And
Including a receiving unit for receiving the uplink data channel from the terminal based on the information instructing the repeated transmission,
Information indicating the repeated transmission,
Indicate information on the number of repetitive transmissions for the uplink data channel or the downlink data channel,
Information on the number of repeated transmissions,
Indicated by a value of a field indicating repetitive transmission consisting of 2 bits in the downlink control information, and when the value of the field is the maximum value, it is determined according to a value configured through higher layer signaling,
The repeated transmission,
A base station, characterized in that performed in units of slots or subslots. The method of claim 19,
The base station, characterized in that the subslot is composed of two or three symbols. The method of claim 19,
The base station, characterized in that the maximum value of the number of repeated transmissions that the information indicating the repeated transmission can indicate is 6. The method of claim 19,
The base station, characterized in that the number of repetitive transmission is 3 or 6. The method of claim 19,
The base station, characterized in that the sequence of the redundancy version (RV) for repetitive transmission consists of six elements. The method of claim 23,
Each element of the sequence is set to one of four patterns,
The base station, wherein the pattern of the first element and the pattern of the fifth element of the sequence are the same, and the pattern of the second element and the pattern of the sixth element of the sequence are the same.

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