WO2018231032A1 - Method and apparatus for transmitting and receiving wireless signal in wireless communication system - Google Patents

Abstract

The present invention relates to a wireless communication system and, more particularly, to a method comprising: a step of receiving data at time unit #n on a first frequency band; and a step of transmitting an A/N for the data at time unit #m+k on a second frequency band, wherein the first frequency band and the second frequency band have different subcarrier spacing, and time unit #m of the second frequency band represents the final time unit of a plurality of time units of the second frequency band corresponding to time unit #n of the first frequency band, and an apparatus therefor.

Description

Method and apparatus for transmitting and receiving wireless signal in wireless communication system

The present invention relates to a wireless communication system, and more particularly to a method and apparatus for transmitting and receiving wireless signals. The wireless communication system includes a carrier aggregation (CA) -based wireless communication system.

Wireless communication systems are widely deployed to provide various kinds of communication services such as voice and data. In general, a wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency (SC-FDMA). division multiple access) system.

An object of the present invention is to provide a method and an apparatus therefor for efficiently performing a wireless signal transmission and reception process.

Technical problems to be achieved in the present invention are not limited to the above technical problems, and other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

In one aspect of the present invention, a method for a terminal to perform communication in a wireless communication system, the method comprising: receiving data in time unit #n on a first frequency band; And transmitting an Acknowledgment / Negative acknowledgment (A / N) for the data in time unit # m + k on a second frequency band, wherein the first and second frequency bands are different from each other in subcarrier spacing, A time unit #m of the second frequency band is provided indicating a last time unit of a plurality of time units of the second frequency band corresponding to time unit #n of the first frequency band.

In another aspect of the present invention, a terminal used in a wireless communication system, the terminal comprising: a radio frequency (RF) module; And a processor, wherein the processor receives data in time unit #n on a first frequency band, and Acknowledgment / Negative acknowledgment (A / N) for the data in time unit # m + k on a second frequency band. And the first and second frequency bands have different subcarrier spacings from each other, and time unit #m of the second frequency band is the second frequency corresponding to time unit #n of the first frequency band. A terminal indicating the last time unit of the plurality of time units of the band is provided.

In another aspect of the present invention, a method of a base station communicating in a wireless communication system, the method comprising: receiving data in time unit #n on a first frequency band; And transmitting an Acknowledgment / Negative acknowledgment (A / N) for the data in time unit # m + k on a second frequency band, wherein the first and second frequency bands are different from each other in subcarrier spacing, A time unit #m of the second frequency band is provided indicating a last time unit of a plurality of time units of the second frequency band corresponding to time unit #n of the first frequency band.

In another aspect of the present invention, a base station used in a wireless communication system, the base station comprising: a radio frequency (RF) module; And a processor, wherein the processor transmits data in time unit #n on a first frequency band, and Acknowledgment / Negative acknowledgment (A / N) for the data in time unit # m + k on a second frequency band. And the first and second frequency bands have different subcarrier spacings from each other, and time unit #m of the second frequency band is the second frequency corresponding to time unit #n of the first frequency band. A base station is provided that represents the last time unit of the plurality of time units of the band.

Preferably, each time unit includes the same number of orthogonal frequency division multiplexing (OFDM) -based symbols, and the length of each time unit may be determined based on the subcarrier spacing.

Preferably, the subcarrier spacing of the first frequency band may be smaller than the subcarrier spacing of the second frequency band.

Preferably, the information about k may be received through a control channel for scheduling the data.

Preferably, the first frequency band may correspond to a SCell (Secondary Cell), and the second frequency band may correspond to a cell configured to transmit a PUCCH (Physical Uplink Control Channel).

Preferably, the data may be received through a physical downlink shared channel (PDSCH), and the A / N may be transmitted through a physical uplink control channel (PUCCH).

Advantageously, said wireless communication system may comprise a 3rd Generation Partnership Project (3GPP) -based wireless communication system.

According to the present invention, it is possible to efficiently transmit and receive wireless signals in a wireless communication system.

Effects obtained in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description in order to provide a thorough understanding of the present invention, provide an embodiment of the present invention and together with the description, illustrate the technical idea of the present invention.

1 illustrates physical channels used in a 3GPP LTE (-A) system, which is an example of a wireless communication system, and a general signal transmission method using the same.

2 illustrates a structure of a radio frame.

3 illustrates a resource grid of a downlink slot.

4 shows a structure of a downlink subframe.

5 illustrates a structure of an uplink subframe used in LTE (-A).

6 illustrates a Single Carrier Frequency Division Multiple Access (SC-FDMA) scheme and an Orthogonal Frequency Division Multiple Access (OFDMA) scheme.

7 illustrates UL ULQ (Uplink Hybrid Automatic Repeat reQuest) operation.

8 illustrates a Carrier Aggregation (CA) communication system.

9 illustrates cross-carrier scheduling.

10 illustrates the structure of a self-contained subframe.

11 illustrates a frame structure defined in 3GPP NR.

12-16 illustrate signal transmission according to the present invention.

17 illustrates a base station and a terminal that can be applied to the present invention.

The following techniques include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and the like. It can be used in various radio access systems. CDMA may be implemented with a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented in a wireless technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) long term evolution (LTE) is part of Evolved UMTS (E-UMTS) using E-UTRA and LTE-A (Advanced) is an evolved version of 3GPP LTE. For clarity, the following description focuses on 3GPP LTE / LTE-A, but the technical spirit of the present invention is not limited thereto.

In a wireless communication system, a terminal receives information through a downlink (DL) from a base station, and the terminal transmits information through an uplink (UL) to the base station. The information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist according to the type / use of the information transmitted and received.

FIG. 1 is a diagram for explaining physical channels used in a 3GPP LTE (-A) system and a general signal transmission method using the same.

The terminal which is powered on again or enters a new cell while the power is turned off performs an initial cell search operation such as synchronizing with the base station in step S101. To this end, the UE receives a Primary Synchronization Channel (P-SCH) and a Secondary Synchronization Channel (S-SCH) from the base station, synchronizes with the base station, and provides information such as a cell identity. Acquire. Thereafter, the terminal may receive a physical broadcast channel (PBCH) from the base station to obtain broadcast information in a cell. Meanwhile, the terminal may check a downlink channel state by receiving a downlink reference signal (DL RS) in an initial cell search step.

After completing the initial cell discovery, the UE receives a physical downlink control channel (PDSCH) according to physical downlink control channel (PDCCH) and physical downlink control channel information in step S102 to be more specific. System information can be obtained.

Thereafter, the terminal may perform a random access procedure such as steps S103 to S106 to complete the access to the base station. To this end, the UE transmits a preamble through a physical random access channel (PRACH) (S103), a response message to the preamble through a physical downlink control channel and a corresponding physical downlink shared channel. Can be received (S104). In case of contention based random access, contention resolution procedure such as transmission of an additional physical random access channel (S105) and reception of a physical downlink control channel and a corresponding physical downlink shared channel (S106). ) Can be performed.

After performing the above-described procedure, the UE performs a general downlink control channel / physical downlink shared channel reception (S107) and a physical uplink shared channel (PUSCH) / as a general uplink / downlink signal transmission procedure. Physical uplink control channel (PUCCH) transmission (S108) may be performed. The control information transmitted from the terminal to the base station is collectively referred to as uplink control information (UCI). UCI includes Hybrid Automatic Repeat and reQuest Acknowledgment / Negative-ACK (HARQ ACK / NACK), Scheduling Request (SR), Channel State Information (CSI), and the like. The CSI includes a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a Rank Indication (RI), and the like. UCI is generally transmitted through PUCCH, but may be transmitted through PUSCH when control information and traffic data should be transmitted at the same time. In addition, the UCI may be aperiodically transmitted through the PUSCH by the request / instruction of the network.

2 illustrates a structure of a radio frame. The uplink / downlink data packet transmission is performed in subframe units, and the subframe is defined as a time interval including a plurality of symbols. The 3GPP LTE standard supports a type 1 radio frame structure applicable to frequency division duplex (FDD) and a type 2 radio frame structure applicable to time division duplex (TDD).

2 (a) illustrates the structure of a type 1 radio frame. The downlink radio frame consists of 10 subframes, and one subframe consists of two slots in the time domain. The time taken for one subframe to be transmitted is called a transmission time interval (TTI). For example, one subframe may have a length of 1 ms, and one slot may have a length of 0.5 ms. One slot includes a plurality of OFDM symbols in the time domain and a plurality of resource blocks (RBs) in the frequency domain. In the 3GPP LTE system, since OFDM is used in downlink, an OFDM symbol represents one symbol period. An OFDM symbol may also be referred to as an SC-FDMA symbol or symbol period. A resource block (RB) as a resource allocation unit may include a plurality of consecutive subcarriers in one slot.

The number of OFDM symbols included in the slot may vary depending on the configuration of a cyclic prefix (CP). CP has an extended CP (normal CP) and a normal CP (normal CP). For example, when an OFDM symbol is configured by a normal CP, the number of OFDM symbols included in one slot may be seven. When the OFDM symbol is configured by an extended CP, since the length of one OFDM symbol is increased, the number of OFDM symbols included in one slot is smaller than that of the normal CP. For example, in the case of an extended CP, the number of OFDM symbols included in one slot may be six. When the channel state is unstable, such as when the terminal moves at a high speed, an extended CP may be used to further reduce intersymbol interference.

When the normal CP is used, since the slot includes 7 OFDM symbols, the subframe includes 14 OFDM symbols. First up to three OFDM symbols of a subframe may be allocated to a physical downlink control channel (PDCCH), and the remaining OFDM symbols may be allocated to a physical downlink shared channel (PDSCH).

2 (b) illustrates the structure of a type 2 radio frame. Type 2 radio frames consist of two half frames. The half frame includes 4 (5) normal subframes and 1 (0) special subframes. The general subframe is used for uplink or downlink according to the UL-Downlink configuration. The subframe consists of two slots.

Table 1 illustrates a subframe configuration in a radio frame according to the UL-DL configuration.

Uplink-downlink configuration

Downlink-to-Uplink Switch point periodicity

Subframe number

0

One

2

3

4

5

6

7

8

9

0

5 ms

D

S

U

U

U

D

S

U

U

U

One

5 ms

D

S

U

U

D

D

S

U

U

D

2

5 ms

D

S

U

D

D

D

S

U

D

D

3

10 ms

D

S

U

U

U

D

D

D

D

D

4

10 ms

D

S

U

U

D

D

D

D

D

D

5

10 ms

D

S

U

D

D

D

D

D

D

D

6

5 ms

D

S

U

U

U

D

S

U

U

D

In the table, D represents a downlink subframe, U represents an uplink subframe, and S represents a special subframe. The special subframe includes a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS). DwPTS is used for initial cell search, synchronization or channel estimation at the terminal. UpPTS is used for channel estimation at the base station and synchronization of uplink transmission of the terminal. The guard period is a period for removing interference generated in the uplink due to the multipath delay of the downlink signal between the uplink and the downlink.

The structure of the radio frame is merely an example, and the number of subframes, the number of slots, and the number of symbols in the radio frame may be variously changed.

3 illustrates a resource grid of a downlink slot.

Referring to FIG. 3, the downlink slot includes a plurality of OFDM symbols in the time domain. Here, one downlink slot includes 7 OFDM symbols and one resource block (RB) is illustrated as including 12 subcarriers in the frequency domain. However, the present invention is not limited thereto. Each element on the resource grid is referred to as a resource element (RE). One RB contains 12x7 REs. The number NDL of RBs included in the downlink slot depends on the downlink transmission band. The structure of the uplink slot may be the same as the structure of the downlink slot.

4 illustrates a structure of a downlink subframe.

Referring to FIG. 4, up to three (4) OFDM symbols located in front of the first slot in a subframe correspond to a control region to which a control channel is allocated. The remaining OFDM symbol corresponds to a data region to which a physical downlink shared chance (PDSCH) is allocated, and a basic resource unit of the data region is RB. Examples of downlink control channels used in LTE include a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical hybrid ARQ indicator channel (PHICH), and the like. The PCFICH is transmitted in the first OFDM symbol of a subframe and carries information on the number of OFDM symbols used for transmission of a control channel within the subframe. The PHICH is a response to uplink transmission and carries an HARQ ACK / NACK (acknowledgment / negative-acknowledgment) signal. Control information transmitted on the PDCCH is referred to as downlink control information (DCI). DCI includes uplink or downlink scheduling information or an uplink transmit power control command for a certain group of terminals.

Control information transmitted through the PDCCH is referred to as downlink control information (DCI). The DCI format has formats 0, 3, 3A, 4 for uplink, formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, 2C, etc. defined for downlink. The type of the information field, the number of information fields, the number of bits of each information field, etc. vary according to the DCI format. For example, the DCI format may include a hopping flag, an RB assignment, a modulation coding scheme (MCS), a redundancy version (RV), a new data indicator (NDI), a transmit power control (TPC), It optionally includes information such as a HARQ process number and a precoding matrix indicator (PMI) confirmation. Accordingly, the size of control information matched to the DCI format varies according to the DCI format. Meanwhile, any DCI format may be used for transmitting two or more kinds of control information. For example, DCI format 0 / 1A is used to carry DCI format 0 or DCI format 1, which are distinguished by a flag field.

The PDCCH includes a transmission format and resource allocation of a downlink shared channel (DL-SCH), resource allocation information for an uplink shared channel (UL-SCH), paging information for a paging channel (PCH), and system information on the DL-SCH. ), Resource allocation information of a higher-layer control message such as a random access response transmitted on a PDSCH, transmission power control commands for individual terminals in an arbitrary terminal group, activation of voice over IP (VoIP), and the like. . A plurality of PDCCHs may be transmitted in the control region. The terminal may monitor the plurality of PDCCHs. The PDCCH is transmitted on an aggregation of one or a plurality of consecutive CCEs (consecutive control channel elements). CCE is a logical allocation unit used to provide a PDCCH of a predetermined coding rate according to the state of a radio channel. The CCE corresponds to a plurality of resource element groups (REGs). The format of the PDCCH and the number of bits of the available PDCCH are determined according to the correlation between the number of CCEs and the code rate provided by the CCEs. The base station determines the PDCCH format according to the DCI to be transmitted to the terminal, and adds a cyclic redundancy check (CRC) to the control information. The CRC is masked with a unique identifier (referred to as a radio network temporary identifier (RNTI)) depending on the owner of the PDCCH or the intended use. If the PDCCH is for a specific terminal, a unique identifier (eg, C-RNTI (cell-RNTI)) of the terminal is masked on the CRC. As another example, if the PDCCH is for a paging message, a paging indication identifier (eg, p-RNTI (p-RNTI)) is masked in the CRC. If the PDCCH relates to system information (more specifically, a system information block (SIB) to be described later), a system information identifier (eg, a system information RNTI (SI-RNTI)) is masked to the CRC. A random access-RNTI (RA-RNTI) is masked in the CRC to indicate a random access response, which is a response to the transmission of the random access preamble of the terminal.

The PDCCH carries a message known as Downlink Control Information (DCI), and the DCI includes resource allocation and other control information for one terminal or a group of terminals. In general, a plurality of PDCCHs may be transmitted in one subframe. Each PDCCH is transmitted using one or more Control Channel Elements (CCEs), and each CCE corresponds to nine sets of four resource elements. The four resource elements are referred to as resource element groups (REGs). Four QPSK symbols are mapped to one REG. The resource element allocated to the reference signal is not included in the REG, so that the total number of REGs within a given OFDM symbol depends on the presence of a cell-specific reference signal. The REG concept (ie group-by-group mapping, each group contains four resource elements) is also used for other downlink control channels (PCFICH and PHICH). That is, REG is used as a basic resource unit of the control region. Four PDCCH formats are supported as listed in Table 2.

PDCCH format	Number of CCEs (n)	Number of REGs	Number of PDCCH bits
0	One	9	72
One	2	8	144
2	4	36	288
3	5	72	576

CCEs are numbered consecutively, and to simplify the decoding process, a PDCCH with a format consisting of n CCEs can only start with a CCE having the same number as a multiple of n. The number of CCEs used for transmission of a specific PDCCH is determined by the base station according to channel conditions. For example, if the PDCCH is for a terminal having a good downlink channel (eg, close to a base station), one CCE may be sufficient. However, in case of a terminal having a bad channel (eg, close to a cell boundary), eight CCEs may be used to obtain sufficient robustness. In addition, the power level of the PDCCH may be adjusted according to channel conditions.

The approach introduced in LTE is to define a limited set of CCE locations where the PDCCH can be located for each terminal. The limited set of CCE locations where the UE can find its own PDCCH may be referred to as a search space (SS). In LTE, the search space has a different size according to each PDCCH format. In addition, UE-specific and common search spaces are defined separately. The UE-Specific Search Space (USS) is set individually for each terminal, and the range of the Common Search Space (CSS) is known to all terminals. UE-specific and common search spaces may overlap for a given terminal. In case of having a relatively small search space, since there are no remaining CCEs when some CCE positions are allocated in the search space for a specific UE, within a given subframe, the base station may not find CCE resources for transmitting the PDCCH to all possible UEs. The UE-specific hopping sequence is applied to the start position of the UE-specific search space in order to minimize the possibility of the above blocking leading to the next subframe.

Table 3 shows the sizes of common and UE-specific search spaces.

PDCCH format	Number of CCEs (n)	Number of candidates in common search space	Number of candidates in dedicated search space
0	One	-	6
One	2	-	6
2	4	4	2
3	8	2	2

In order to keep the computational load according to the total number of blind decoding (BD) under control, the terminal is not required to simultaneously search all defined DCI formats. In general, within a UE-specific search space, the terminal always searches for formats 0 and 1A. Formats 0 and 1A have the same size and are distinguished by flags in the message. In addition, the terminal may be required to receive the additional format (eg, 1, 1B or 2 depending on the PDSCH transmission mode set by the base station). In the common search space, the UE searches for formats 1A and 1C. In addition, the terminal may be configured to search for format 3 or 3A. Formats 3 and 3A have the same size as formats 0 and 1A and can be distinguished by scrambled CRCs with different (common) identifiers, rather than terminal-specific identifiers. PDSCH transmission schemes according to transmission modes and information contents of DCI formats are listed below.

Transmission Mode (TM)

Transmission mode 1: Transmission from a single base station antenna port

● Transmission Mode 2: Transmission Diversity

Transmission Mode 3: Open-Loop Space Multiplexing

Transmission mode 4: closed-loop spatial multiplexing

Transmission Mode 5: Multi-User MIMO

● Transmission mode 6: closed-loop rank-1 precoding

● Transmission Mode 7: Single-antenna Port (Port 5) Transmission

● Transmission Mode 8: Double Layer Transmission (Ports 7 and 8) or Single-Antenna Port (Ports 7 or 8) Transmission

● Transfer Mode 9: Up to eight layer transfers (ports 7 to 14) or single-antenna ports (ports 7 or 8)

DCI format

Format 0: Resource grant for PUSCH transmission (uplink)

Format 1: Resource allocation for single codeword PDSCH transmission ( transmission modes 1, 2 and 7)

Format 1A: compact signaling of resource allocation for a single codeword PDSCH (all modes)

Format 1B: Compact resource allocation for PDSCH (mode 6) using rank-1 closed-loop precoding

Format 1C: very compact resource allocation for PDSCH (eg paging / broadcast system information)

Format 1D: compact resource allocation for PDSCH (mode 5) using multi-user MIMO

Format 2: Resource Allocation for PDSCH (Mode 4) of Closed-Root MIMO Operation

Format 2A: resource allocation for PDSCH (mode 3) of open-loop MIMO operation

Format 3 / 3A: power control command with 2-bit / 1-bit power adjustment value for PUCCH and PUSCH

5 illustrates a structure of an uplink subframe used in LTE (-A).

Referring to FIG. 5, the subframe 500 is composed of two 0.5 ms slots 501. Assuming the length of a Normal Cyclic Prefix (CP), each slot consists of seven symbols 502 and one symbol corresponds to one SC-FDMA symbol. The resource block (RB) 503 is a resource allocation unit corresponding to 12 subcarriers in the frequency domain and one slot in the time domain. The structure of an uplink subframe of LTE (-A) is largely divided into a data region 504 and a control region 505. The data area means a communication resource used in transmitting data such as voice and packet transmitted to each terminal, and includes a PUSCH (Physical Uplink Shared Channel). The control region means a communication resource used to transmit an uplink control signal, for example, a downlink channel quality report from each terminal, a received ACK / NACK for an uplink signal, an uplink scheduling request, and a PUCCH (Physical Uplink). Control Channel). The sounding reference signal (SRS) is transmitted through an SC-FDMA symbol located last on the time axis in one subframe. SRSs of multiple terminals transmitted in the last SC-FDMA of the same subframe can be distinguished according to frequency location / sequence. The SRS is used to transmit an uplink channel state to a base station, and is periodically transmitted according to a subframe period / offset set by a higher layer (eg, an RRC layer), or aperiodically at the request of the base station.

6 is a diagram for explaining an SC-FDMA scheme and an OFDMA scheme. The 3GPP system employs OFDMA in downlink and SC-FDMA in uplink.

Referring to FIG. 6, both a terminal for uplink signal transmission and a base station for downlink signal transmission are serial-to-parallel converter 401, subcarrier mapper 403, and M-point IDFT module 404. ) And the Cyclic Prefix (CP) addition module 406 are the same. However, the terminal for transmitting a signal in the SC-FDMA scheme further includes an N-point DFT module 402. The N-point DFT module 402 partially offsets the IDFT processing impact of the M-point IDFT module 404 so that the transmitted signal has a single carrier property.

Next, HARQ (Hybrid Automatic Repeat reQuest) will be described. When there are a plurality of terminals having data to be transmitted in uplink / downlink in a wireless communication system, the base station selects a terminal to transmit data for each transmission time interval (TTI) (eg, subframe). In a multi-carrier and similarly operated system, the base station selects terminals to transmit data in uplink / downlink for each TTI and selects a frequency band used by the terminal for data transmission.

Referring to the uplink, UEs transmit reference signals (or pilots) in uplink, and the base station determines the channel state of the UEs using the reference signals transmitted from the UEs in each unit frequency band for each TTI. Select terminals to transmit data in the uplink. The base station informs the terminal of this result. That is, the base station transmits an uplink assignment message for transmitting data using a specific frequency band to an uplink scheduled terminal in a specific TTI. The uplink assignment message is also referred to as a UL grant. The terminal transmits data in the uplink according to the uplink assignment message. The uplink allocation message may include a UE ID, RB allocation information, a Modulation and Coding Scheme (MCS), a Redundancy Version (RV) version, a New Data Indicator (NDI), and the like.

In the case of the synchronous HARQ scheme, the retransmission time is systematically promised (for example, 4 subframes after the NACK reception time) (synchronous HARQ). Therefore, the UL grant message transmitted from the base station to the terminal only needs to be transmitted during initial transmission, and subsequent retransmission is performed by an ACK / NACK signal (eg, PHICH signal). In the asynchronous HARQ scheme, since the retransmission time is not promised to each other, the base station should send a retransmission request message to the terminal. In addition, in the non-adaptive HARQ scheme, the frequency resource or MCS for retransmission is the same as the previous transmission. In the adaptive HARQ scheme, the frequency resource or MCS for the retransmission may be different from the previous transmission. For example, in the case of the asynchronous adaptive HARQ scheme, since the frequency resource or the MCS for retransmission varies for each transmission time point, the retransmission request message may include a terminal ID, RB allocation information, HARQ process ID / number, RV, and NDI information. .

7 illustrates UL HARQ operation in an LTE (-A) system. In the LTE (-A) system, the UL HARQ scheme uses synchronous non-adaptive HARQ. When using 8-channel HARQ, the HARQ process number is given from 0 to 7. One HARQ process operates per TTI (eg, subframe). Referring to FIG. 8, the base station 110 transmits a UL grant to the terminal 120 through the PDCCH (S600). The terminal 120 transmits uplink data to the base station S110 using the RB and MCS designated by the UL grant after 4 subframes (eg, subframe 4) from the time point (eg, subframe 0) at which the UL grant is received. It transmits (S602). The base station 110 generates ACK / NACK after decoding uplink data received from the terminal 120. If decoding on the uplink data fails, the base station 110 transmits a NACK to the terminal 120 (S604). The terminal 120 retransmits uplink data after 4 subframes from the time point of receiving the NACK (S606). Initial transmission and retransmission of uplink data is in charge of the same HARQ processor (eg, HARQ process 4). ACK / NACK information may be transmitted through PHICH.

8 illustrates a Carrier Aggregation (CA) communication system.

Referring to FIG. 8, a plurality of uplink / downlink component carriers (CCs) may be collected to support a wider uplink / downlink bandwidth. Each of the CCs may be adjacent or non-adjacent to each other in the frequency domain. The bandwidth of each component carrier can be determined independently. It is also possible to merge asymmetric carriers in which the number of UL CCs and the number of DL CCs are different. Meanwhile, the control information may be set to be transmitted and received only through a specific CC. This particular CC may be referred to as the primary CC and the remaining CCs may be referred to as the secondary CC. For example, when cross-carrier scheduling (or cross-CC scheduling) is applied, the PDCCH for downlink allocation may be transmitted in DL CC # 0, and the corresponding PDSCH may be transmitted in DL CC # 2. have. The term “component carrier” may be replaced with other equivalent terms (eg, carrier, cell, etc.).

For cross-CC scheduling, a carrier indicator field (CIF) is used. Configuration for the presence or absence of CIF in the PDCCH may be semi-statically enabled by higher layer signaling (eg, RRC signaling) to be UE-specific (or UE group-specific). The basics of PDCCH transmission can be summarized as follows.

■ CIF disabled: The PDCCH on the DL CC allocates PDSCH resources on the same DL CC and PUSCH resources on a single linked UL CC.

  ● No CIF

■ CIF enabled: A PDCCH on a DL CC may allocate a PDSCH or PUSCH resource on one DL / UL CC among a plurality of merged DL / UL CCs using the CIF.

  LTE DCI format extended to have CIF

    CIF (if set) is a fixed x-bit field (eg x = 3)

    -CIF (if set) position is fixed regardless of DCI format size

In the presence of CIF, the base station may allocate a monitoring DL CC (set) to reduce the BD complexity at the terminal side. For PDSCH / PUSCH scheduling, the UE may perform detection / decoding of the PDCCH only in the corresponding DL CC. In addition, the base station may transmit the PDCCH only through the monitoring DL CC (set). The monitoring DL CC set may be set in a terminal-specific, terminal-group-specific or cell-specific manner.

9 illustrates scheduling when a plurality of carriers are merged. Assume that three DL CCs are merged. Assume that DL CC A is set to PDCCH CC. DL CC A to C may be referred to as a serving CC, a serving carrier, a serving cell, and the like. If CIF is disabled, each DL CC can transmit only PDCCH scheduling its PDSCH without CIF according to the LTE PDCCH rule (non-cross-CC scheduling). On the other hand, if CIF is enabled by UE-specific (or UE-group-specific or cell-specific) higher layer signaling, a specific CC (eg, DL CC A) schedules PDSCH of DL CC A using CIF. Not only PDCCH but also PDCCH scheduling PDSCH of another CC may be transmitted (cross-CC scheduling). On the other hand, PDCCH is not transmitted in DL CC B / C.

Meanwhile, in the next generation of radio access technology (RAT), self-contained subframes are considered to minimize data transmission latency. 10 illustrates the structure of a self-completed subframe. In FIG. 10, hatched areas represent DL control areas, and black areas represent UL control areas. An area without an indication may be used for DL data transmission or may be used for UL data transmission. Since DL and UL transmissions are sequentially performed in one subframe, DL data may be transmitted in a subframe and UL ACK / NACK may be received. As a result, when data transmission error occurs, it takes less time to retransmit data, thereby minimizing the transmission latency of final data.

As an example of a configurable / configurable self-complete subframe type, at least the following four subframe types may be considered. Each interval is listed in chronological order.

DL control section + DL data section + GP (Guard Period) + UL control section

DL control section + DL data section

DL control section + GP + UL data section + UL control section

DL control section + GP + UL data section

PDFICH, PHICH, PDCCH may be transmitted in the DL control period, and PDSCH may be transmitted in the DL data period. PUCCH may be transmitted in the UL control period, and PUSCH may be transmitted in the UL data period. The GP provides a time gap in the process of the base station and the terminal switching from the transmission mode to the reception mode or from the reception mode to the transmission mode. Some OFDM symbols at the time of switching from DL to UL in the subframe may be set to GP.

Embodiment: CA scheme between different OFDM numerologies

In a 3GPP NR system environment, an OFDM new monolith, for example, a subcarrier spacing (SCS) and an OFDM symbol (OS) duration based thereon, may be configured between a plurality of cells merged into one UE. Accordingly, the (absolute time) section of a time resource (eg, SF, slot, or TTI) (commonly referred to as a time unit (TU) for convenience) composed of the same number of symbols may be set differently between merged cells. Here, the symbol may include an OFDM symbol and an SC-FDMA symbol.

11 illustrates a frame structure defined in 3GPP NR. As in the radio frame structure of LTE / LTE-A (see FIG. 2), in 3GPP NR, one radio frame is composed of 10 subframes, and each subframe has a length of 1 ms. One subframe includes one or more slots and the slot length depends on the SCS. 3GPP NR supports SCS of 15KHz, 30KHz, 60KHz, 120KHz and 240KHz. Here, the slot corresponds to the TTI of FIG. 10.

Table 4 illustrates that the number of symbols per slot, the number of slots per frame, and the number of slots for each subframe vary according to SCS.

SCS (15 * 2 ^ u)	Number of slot symbols	Number of slots in the frame	Number of slots in subframe
15KHz (u = 0)	14	10	One
30KHz (u = 1)	14	20	2
60KHz (u = 2)	14	40	4
120KHz (u = 3)	14	80	8
240KHz (u = 4)	14	160	16

In view of this, DL / UL data related HARQ process in a CA situation between cells having different SCS and OS intervals (eg, DL in SCell when DL / UL data transmission in SCell is cross-CC scheduled from PCell) For the case where A / N feedback corresponding to data reception is transmitted through the PCell, the following operation method may be considered. In the following invention, the same principle may be applied to a situation in which a TU (eg, slot) section is set differently between cells in an inter-cell CA situation having the same SCS and OS section.

Hereinafter, the present invention will be described focusing on the case where the TU is a slot with reference to the NR frame structure. Depending on the system, the TU may be defined in various time resource units. In addition, in the following description, a PCell may be generalized to a cell (hereinafter, referred to as a PUCCH cell) configured to transmit a PUCCH. For example, the PUCCH cell may also include a specific SCell (eg, Primary Secondary Cell, PSCell) configured to transmit the PUCCH. In addition, the SCell to which data is transmitted / received may be generalized to a data cell or a scheduled cell, and the cell to which the grant DCI is transmitted may be generalized to a control cell or a scheduling cell. In addition, the cell may be replaced with a component carrier (CC). In addition, DCI may be transmitted through the PDCCH, UL data may be transmitted through the PUSCH, and DL data may be transmitted through the PDSCH.

(A) Cross-CC scheduling between different SCS

FIG. 12 is a case where a cell X having a large SCS (ie, a short OS period or a short TU (eg, slot) period) is configured to be scheduled from a cell Y having a small SCS (ie, a long OS period or a long TU period). To illustrate. Referring to FIG. 12, DL / UL data transmission in K (K> 1) TUs of cell X may be configured to be scheduled from one TU of cell Y. A single TU of cell Y and K (eg, multiples of 2) TU of cell X may have the same time interval. In this case, Opt 1) simultaneous transmission / detection of DL / UL grants scheduling different (maximum) K TUs of cell X through one DL control channel transmission region (in a single TU) of cell Y, or Opt 2 In a state in which K DL control channel transmission regions are independently configured / configured within a single TU of cell Y, DL / UL grants that schedule different single TUs in cell X may be transmitted / detected through each region. In this case, which TU of K TUs of cell X corresponding to a single TU section of cell Y may be scheduled may be indicated through a DL / UL grant.

Simultaneous detection / reception of multiple DCI operations in the above methods (particularly Opt 1) is achieved by parallel (decoding) on the terminal implementation for the corresponding multiple DL / UL data channels (and multiple PDCCHs carrying DL / UL grant DCIs scheduling them). May be supported differently depending on the processing capability. For example, in the case of a terminal supporting a cross-CC scheduling operation between a scheduling cell Y operating in a specific SCS and a scheduled cell X operating in an SCS that is K times larger than the corresponding SCS, one DL control channel transmission / search (resource) Terminal capability / implementation may be defined to enable simultaneous detection / reception up to (at least) up to K DL (UL) grant DCIs (and thus up to K DL (UL) data processing may be performed simultaneously) through the region. . As another example, the maximum number of DL (UL) grant DCIs (eg, Lu) that can be simultaneously detected / received through one DL control channel transmission / search (resource) region (under the cross-CC scheduling configuration as described above) It may vary depending on the implementation. Accordingly, the terminal may report its capability (ie, Lu value) related to the operation to the base station. As another example, a UE (under a cross-CC scheduling configuration as shown in FIG. 12) may have a maximum number of DL (UL) grant DCIs (via one DL control channel transmission / search (resource) region) (eg, Lc). Up to (from the base station) can be configured from the base station whether the simultaneous scheduling / transmission possible. Accordingly, the UE may perform blind decoding in a state where simultaneous detection / reception is possible up to Lc DL (UL) grant DCIs.

The method / operation may include: DL / UL transmitted over any cell (with DL grant DCI-to-DL data timing (or UL grant DCI-to-UL data timing) being dynamically indicated via DCI). The same may be applied to a self-CC scheduling configuration situation in which data is scheduled from a DCI transmitted through a corresponding cell itself, or a cross-CC scheduling configuration situation between a scheduled cell X and a scheduling cell Y operating in the same SCS. For example, the maximum number of DL (UL) grant DCIs (eg, Lu) that can be simultaneously detected / received through one DL control channel transmission / search (resource) region may vary depending on the terminal implementation. May report its capability (ie, Lu value) with respect to the operation to the base station. As another example, the terminal may configure, from the base station, up to how many (eg, Lc) DL (UL) grant DCIs (from the base station) may be simultaneously scheduled (send from a base station) (via one DL control channel transmission / search (resource) region). I can receive it. Accordingly, the UE may perform blind decoding in a state where simultaneous detection / reception is possible up to Lc DL (UL) grant DCIs.

Meanwhile, a plurality of DL grant DCIs for scheduling a plurality of different DL data (eg, PDSCHs) transmitted through one CC (eg, a data CC) may have the same slot (the same) within a specific CC (eg, a control CC). It can be set to be transmitted through the same control resource set or PDCCH search space in the slot. The control CC indicates a CC to which the UE should monitor the PDCCH, and may be set to be the same as the CC (that is, the data CC) in which data transmission / reception is performed according to the cross-CC scheduling configuration, or may be set to a different CC from the data CC. have. On the other hand, for the purpose of dynamic HARQ-ACK payload (codebook) configuration, how many DLs (and / or up to the current slot) DL data transmitted over a particular CC is scheduled (based on the CC index) Counter-DAI (and / or total-DAI) signaling that informs whether data is scheduled) may be applied through the DL grant DCI. When a plurality of DL grant DCIs corresponding to a plurality of DL data transmitted in the same data CC is transmitted in the same slot (the same set of control resources or PDCCH search space in the corresponding slot) in the control CC, the counter-DAI signaled through the corresponding multiple DCI Criteria for determining the order / size of values may be needed. To this end, a method of determining a counter-DAI value according to the following index (eg, mapping a small counter-DAI value to a low index) may be considered.

1) CCE Index

2) PDCCH candidate index used for DL grant DCI transmission

3) Index of PDCCH search space or control resource set to which DL grant PDCCH is transmitted

4) Slot index (of data CC) where DL data is transmitted

5) First or last symbol index assigned to DL data transmission

6) Index of DL data resource candidate (combined slot offset / start symbol / interval) set to RRC

FIG. 13 illustrates a case where a cell X having a small SCS (ie, a long OS or a long TU interval) is configured to be scheduled from a cell Y having a large SCS (ie, a short OS or a short TU interval). Referring to FIG. 13, DL / UL data transmission in a single TU of cell X may be configured to be scheduled from all N (N> 1) TUs of cell Y or a specific portion (eg, one) TU of cell Y. . N (eg, multiples of 2) TUs of cell Y and a single TU of cell X may have the same time interval (for convenience, referred to as N TUs of cell Y aligned to a single TU of cell X). In this case, Opt 1) DL / UL grant scheduling one TU of cell X through one TU belonging to all TUs of cell Y or a plurality of TUs (that is, TU groups) corresponding to a specific part thereof. 13 (a), or Opt 2) one of the N TUs of cell Y (e.g., the first OS and time in the TU of cell X or the first TU in time of N TUs) A DL / UL grant scheduling one TU of cell X may be transmitted / detected only through TUs of cells Y overlapping each other (FIG. 13 (b)).

In the above methods (particularly Opt 1), the DCI simultaneous detection / reception operation may be supported differently depending on the buffering processing capability on the terminal implementation for the corresponding DL / UL data channel. For example, in the case of a terminal supporting a cross-CC scheduling operation between a scheduled cell X operating in a specific SCS and a scheduling cell Y operating in an SCS that is N times larger than the corresponding SCS, the cell Y aligned with the TU of the cell X UE capability / implementation may be defined to enable detection / reception of DL (UL) grant DCI scheduling TU of the corresponding cell X through any TU of N TUs (so that buffering processing of DL data may be performed). . As another example, a TU capable of detecting / receiving a DL (UL) grant DCI scheduling the TU of cell X among N TUs of aligned cell Y (under the cross-CC scheduling configuration as shown in FIG. 13). The timing may vary depending on the terminal implementation. Accordingly, the terminal may report its capability related to the operation (ie, TU timing information of the cell Y capable of detecting / receiving a DL (UL) grant DCI scheduling the TU of the cell X) to the base station. As another example, DL (UL) data start symbol transmitted through the TU of the cell X (its start symbol / time point) among the N TUs of the aligned cell Y (under the cross-CC scheduling configuration as shown in FIG. 13). The DL (UL) grant DCI detection / reception that schedules the TU of cell X may be limited only through TUs (of cell Y) that are earlier or equal to / time.

On the other hand, in the case of Opt 1, the TU timing at which the DL / UL grant is transmitted in the TU group may change over time, and each of the DL / UL grants may be transmitted through different TUs in the TU group. Accordingly, the UE may perform blind decoding operations sequentially on DL control channel transmission regions within all TUs belonging to the corresponding TU group, and DL / UL grant for cell X may be performed within one TU group of cell Y. The blind decoding operation may be omitted for the DL control channel transmission region in the remaining TUs after all of the detected times. In addition, in the case of Opt 1, the number of blind decodings (for example, Nb) for the DL control channel allocated to the single TU scheduling of cell X is distributed to a plurality of (for example, Ns) TUs constituting the TU group of cell Y. The DL control channel detection operation of the terminal may be performed in a form of (eg, performing (Nb / Ns) blind decoding in each TU). Meanwhile, in Opt 2, a specific TU for transmitting a DL / UL grant for cell X among N TUs of cell Y may be set through a higher layer signal (eg, RRC signaling) or a predefined rule ( For example, the first TU of the N TUs of the cell Y at the same time point as the TU of the cell X may be automatically designated.

On the other hand, when a cell X having a large TU length is configured to cross-CC schedule a cell Y having a small TU length, scheduling for a plurality of TUs of the cell Y in a single TU of the cell X (the accompanying DL / UL grant DCI DL control resource burden may be increased. Taking this into consideration, the difference between the long TU length of (scheduling) cell X and the short TU length of (scheduled) cell Y is below a certain level (e.g., when the TU of cell X is below a certain multiple of TU of cell Y). To allow cross-CC scheduling only. As another method, a method of limiting the number of cells Y of the short TU set to cross-CC scheduling from the cell X of the long TU may be considered below a specific value.

(B) HARQ-ACK timing for CA with different SCS

1) DL data-to-HARQ-ACK

In the CA situation of the 3GPP NR system, the SCS or OS interval (or TU length) is established between a cell (for example, SCell) in which DL data is transmitted and a cell (for example, PCell) in which A / N feedback corresponding to DL data reception is transmitted. Can be set differently. In this case, the A / N timing (eg, delay between DL data reception and A / N transmission) may be set based on the TU length of the DL data transmission SCell (eg, A / N timing (candidate set)). Can be set based on the TU length of the PCell TU length (eg, A / N timing (candidate set) is set to a multiple of the PCell TU length). Opt 1-1 can be understood to set the A / N timing based on the pneumology used for DL data transmission (eg PDSCH transmission), Opt 1-2 is A / N transmission (eg PUCCH transmission) It can be understood that the A / N timing is set based on the pneumology used for. For convenience, the A / N timing set in accordance with Opt 1-1 / 2 is referred to as temp A / N timing. Here, information regarding the A / N timing (for example, the number of TUs) may be indicated through a DL grant scheduling DL data.

First, the actual A / N timing on the PCell that is actually applied in the case of Opt 1-1 is a time and time after temp A / N timing (eg, time corresponding to N SCell TUs) from the DL data reception time on the SCell. It may be determined as a TU (or (for A / N) UL control channel transmission) section on the fastest PCell existing after that including a time point or a corresponding time point. Specifically, assuming that DL data reception time is SCell TU #k, when PCell TU length <SCell TU length, specific (eg, first or first) among a plurality of PCell TUs at the same time as SCell TU # (k + N) Lastly, one PCell TU #n may be determined by actual A / N timing. Here, PCell TU #n, which is the actual A / N timing among the plurality of PCell TUs at the same time as the SCell TU # (k + N), is set through a higher layer signal (eg, RRC signaling) or the DL grant. It may be dynamically indicated through DCI or the like, or may be automatically assigned based on a predefined rule (eg, the first or last TU of the plurality of PCell TUs). Additionally, the number of candidate A / N timing gadgets that can be indicated through the DL grant is 1 so that the DL data of the SCell has less than the DL data of the PCell (e.g., when the TU lengths of the two cells are N times related, To a value corresponding to / N). In this case, two cells may have the same interval between candidate A / N timings corresponding to DL data of each cell.

On the other hand, in the case of PCell TU length> SCell TU length, PCell TU #n at the same time as SCell TU # (k + N) or PCell TU # (n + 1), which is the next TU, may be determined as the actual HARQ timing. have. Here, the TU which is the actual A / N timing among PCell TU #n and PCell TU # (n + 1) is set through higher layer signals (eg, RRC signaling) or the like and is dynamically indicated through DL grant DCI. Or it can be automatically assigned based on predefined rules. For example, according to a predefined rule, the TU which is the actual A / N timing of PCell TU #n and PCell TU # (n + 1) is a PCell if the PUCCH transmission interval or number of symbols in the PCell is less than or equal to a specific value. TU #n, if a certain value is exceeded, it is designated as PCell TU # (n + 1), and / or the order of SCell TU # (k + N) among multiple SCell TUs at the same time point as PCell TU #n If it is less than a specific value, it may be determined as PCell TU #n, and if it exceeds a certain value, it may be determined as PCell TU # (n + 1).

In addition, the interval between candidate A / N timings (N), which can be indicated through the DL grant, is such that DL data of the SCell has a larger interval than DL data of the PCell (e.g., the TU length of two cells is N times the relationship). In this case, a multiple of the corresponding N value) may be set. In this case, the candidate A / N timing number may be set such that the two cells have the same number.

In addition, the actual A / N timing on the PCell that is actually applied in the case of Opt 1-2 is a time when the DL data on the SCell overlaps in time with the time when the TU on the fastest PCell exists after and including the corresponding time. (Or (for A / N) UL control channel transmission) to the TU (or (for A / N) UL control channel transmission) interval after temp A / N timing (e.g., time corresponding to M PCell TUs) Can be determined. Specifically, assuming that DL data reception time is SCell TU #n, when PCell TU length <SCell TU length (that is, PCell SCS> SCell SCS), a plurality of PCell TUs at the same time point as SCell TU #n are specified. Based on one PCell TU #k (eg, first or last), PCell TU # (k + M) may be determined as actual A / N timing. Here, "a specific one of the plurality of PCell TUs PCell TU #k" (hereinafter, HARQ-ACK reference TU) is set through a higher layer signal (eg, RRC signaling) or the like, or dynamically through a DL grant DCI or the like. It may be indicated or specified based on a predefined rule (eg, the first or last TU of the plurality of PCell TUs). Conversely, if PCell TU length> SCell TU length or PCell TU length = SCell TU length (ie, PCell SCS <= SCell SCS), PCell TU #k based on PCell TU #k at the same time as SCell TU #n. (k + M) can be determined by the actual A / N timing.

On the other hand, when cell A having a large TU length is configured to transmit A / N for DL data reception in cell Y having a small TU length (ie, cross-CC UCI transmission), a single TU of cell X is configured. Since UL needs to perform a plurality of A / N transmissions (PUCCH transmissions accompanying it) for a plurality of DL data of cell Y, UL control resource burden may be increased. Taking this into consideration, the difference between the (UL control) long TU length of cell X and the short TU length of (DL data) cell Y is below a certain level (e.g., when the TU of cell X is below a certain multiple of the TU of cell Y). It is possible to operate to allow cross-CC UCI transmission only for. Alternatively, it is also possible to limit the number of cells Y of the (DL data) short TU in which the UCI is set to be transmitted through the (UL control) cell X of the long TU to a specific value or less.

2) UL Grant DCI-to-UL Data

In the case of UL HARQ, the SCS or OS interval (or TU length) may be set differently between a cell (eg, PCell) to which a UL grant is transmitted and a cell (eg, SCell) on which UL data transmission corresponding to the corresponding UL grant is performed. Can be. In this case, HARQ timing (e.g., delay between UL grant reception and UL data transmission) may be set based on Opt 2-1) TU length of UL grant transmission PCell (e.g., HARQ timing (candidate set) is set to PCell TU length). Opt 2-2) may be configured based on the TU length of the UL data transmission SCell (eg, HARQ timing (candidate set) is set as a multiple of the SCell TU length). Opt 2-1 may be understood to set the HARQ timing based on the pneumology used for UL grant transmission (eg PDCCH transmission), Opt 2-2 is used for UL data transmission (eg PUSCH transmission) It may be understood that HARQ timing is set based on pneumology. For convenience, the HARQ timing set according to Opt 2-1 / 2 is referred to as temp HARQ timing. Here, information about HARQ timing (eg, number of TUs) may be indicated through a UL grant.

First, the actual HARQ timing on the SCell actually applied in the case of Opt 2-1 overlaps with the time after the temp HARQ timing (for example, time corresponding to K PCell TUs) from the UL grant reception time on the PCell. It may be determined as a TU (or UL data channel transmission) period on the fastest SCell existing after or including the view point or the view point.

On the other hand, the actual HARQ timing on the SCell that is actually applied in the case of Opt 2-2 is the time when the UL grant on the PCell overlaps in time with the time or the TU (or on the earliest SCell thereafter) including the corresponding time point. It may be determined from a UL data channel transmission section to a TU (or UL data channel transmission) section after a temp HARQ timing (eg, time corresponding to L SCell TUs). Specifically, when the UL grant reception time is assumed to be PCell TU #n, when the PCell TU length> SCell TU length (that is, PCell SCS <SCell SCS), the specific SCell TUs of the same time as the PCell TU #n SCell TU # (k + L) may be determined as the actual HARQ timing based on one SCell TU #k (eg, first or last). Here, "a specific SCell TU #k" (hereinafter, UL-HARQ reference TU) among the plurality of SCell TUs is set through a higher layer signal (eg, RRC signaling) or the like, or dynamically through a UL grant DCI or the like. It may be indicated or specified based on a predefined rule (eg, the first or last TU of the plurality of SCell TUs). Conversely, if PCell TU length <SCell TU length or PCell TU length = SCell TU length (that is, PCell SCS> = SCell SCS), SCell TU # (based on SCell TU #k at the same time as PCell TU #n). k + L) may be determined as the actual HARQ timing.

3) DL Grant DCI-to-DL Data

In the case of DL HARQ, the SCS or OS interval (or TU length) may be set differently between a cell (eg, PCell) to which a DL grant is transmitted and a cell (eg, SCell) on which DL data transmission corresponding to the DL grant is performed. Can be. In this case, HARQ timing (eg, delay between DL data transmissions corresponding to DL grant reception) is based on the TU length of the DL grant transmission PCell (eg, HARQ timing (candidate set) is PCell TU length). 3)) or based on the TU length of the DL data transmission SCell (eg, the HARQ timing (candidate set) is a multiple of the SCell TU length). Opt 3-1 may be understood to set the HARQ timing based on the pneumology used for DL grant transmission (eg, PDCCH transmission), and Opt 3-2 is used for DL data transmission (eg PDSCH transmission). It may be understood that HARQ timing is set based on pneumology. For convenience, the HARQ timing set according to Opt 3-1 / 2 is referred to as temp HARQ timing. Here, information on HARQ timing (eg, number of TUs) may be indicated through a DL grant.

First, the actual HARQ timing on the SCell actually applied in the case of Opt 3-1 overlaps with the time after the temp HARQ timing (for example, time corresponding to K PCell TUs) from the DL grant reception time on the PCell. It may be determined as a TU (or DL data channel transmission) interval on the SCell or the fastest SCell present after that including the viewpoint.

On the other hand, the actual HARQ timing on the SCell that is actually applied in the case of Opt 3-2, the time when the DL grant received on the PCell overlaps in time, or the TU (or the fastest TU on the subsequent SCell including the corresponding time) It may be determined from a DL data channel transmission section to a TU (or DL data channel transmission) section after a temp HARQ timing (eg, time corresponding to L SCell TUs). Specifically, when the DL grant reception time is assumed to be PCell TU #n, when the PCell TU length> SCell TU length (that is, PCell SCS <SCell SCS), the specific SCell TUs of the same time as the PCell TU #n SCell TU # (k + L) may be determined as the actual HARQ timing based on one SCell TU #k (eg, first or last). Here, "a specific SCell TU #k" (hereinafter, DL-HARQ reference TU) among the plurality of SCell TUs is set through a higher layer signal (eg, RRC signaling) or the like, or dynamically through a DL grant DCI or the like. It may be indicated or automatically assigned based on a predefined rule (eg, to the first or last TU of the plurality of SCell TUs). Conversely, if PCell TU length <SCell TU length or PCell TU length = SCell TU length (that is, PCell SCS> = SCell SCS), SCell TU # (based on SCell TU #k at the same time as PCell TU #n). k + L) may be determined as the actual HARQ timing.

Preferably, in option 1-2, "the specific one of the plurality of PCell TUs #k" for the HARQ-ACK reference TU may be designated as the last TU of the corresponding plurality of PCell TUs. Since a certain processing time is required to transmit A / N after receiving DL data, for example, when the HARQ-ACK reference TU is designated as the first TU among the plurality of PCell TUs, the A / N is used in the HARQ-ACK reference TU. The transfer cannot be performed. Therefore, when information on A / N timing is indicated through the DL grant DCI, information indicating a specific TU (eg, a TU within a processing time necessary for HARQ-ACK reference TU to A / N transmission) is not valid. Some of the information about the A / N timing cannot be used, so signaling information is limited. For example, when A / N timing is defined as a TU offset having a value of 0 to N-1, 0 to L-1 (L <N) cannot be used for signaling. In addition, as the slot length is varied according to the SCS, the number (L) of TUs within the processing time required for A / N transmission is also varied, thereby increasing the restriction / system complexity of the signaling information.

14 illustrates signal transmission according to option 1-2. Referring to FIG. 14, DL data is received in slot n of cell X (SCS: X KHz). If cell X is not a PUCCH cell (eg, PCell), A / N for DL data may be transmitted in a PUCCH cell (eg, cell Y). In this case, since the SCS of the cell Y is 4X KHz, the slot n of the cell X corresponds to / aligns with the four slots of the cell Y (eg, slots p to slots p + 3), and A / N for the DL data is determined by the cell X. A slot may be transmitted after a k (eg, 4) slot based on the last slot (that is, slot p + 3) of four slots of cell Y corresponding to slot n. Information about k may be indicated through control information for scheduling DL data (eg, DL grant DCI), and k may be an integer of 0 or more. k is set based on the pneumology used for A / N transmission (eg, PUCCH transmission). Here, the DL data may be received through the PDSCH, and the DL grant DCI may be received through the PDCCH. Here, the cell may be replaced with a sub-band as described below.

In addition, in Option 2-2, the "specific SCell TU #k of multiple SCell TUs" for the UL-HARQ reference TU is designated as the last TU of the corresponding multiple SCell TUs, or is an upper layer signal (eg, RRC signaling). It may be set to one of the plurality of SCell TUs. Since a certain processing time is required to transmit UL data after receiving the UL grant DCI, like the HARQ-ACK reference TU, the UL-HARQ reference TU may be designated as the last TU among the plurality of SCell TUs. Meanwhile, for uniformity between UL / DL data processing, like the DL-HARQ reference TU described later, the UL-HARQ reference TU may be designated as the first TU among the plurality of SCell TUs.

15 illustrates signal transmission according to option 2-2. Referring to FIG. 15, UL grant DCI may be received in slot n of cell X (SCS: X KHz), and UL data may be transmitted in cell Y (SCS: 4X KHz). In this case, since the SCS of the cell Y is 4X KHz, the slot n of the cell X corresponds to / aligns with four slots of the cell Y (for example, slots p to slot p + 3), and the UL data corresponds to the slot n of the cell X. Transmitted after slot k (e.g. 4) relative to the last slot (i.e. slot p + 3) of the four slots in cell Y (option 1), or k (based on the first slot (i.e. slot p)). Yes, 7) may be sent after the slot (option 2). Information about k may be indicated through the UL grant DCI, k may be an integer of 0 or more. k is set based on the pneumology used for UL data transmission (eg, PUSCH transmission). In this case, the UL data may be transmitted through the PUSCH, and the UL grant DCI may be received through the PDCCH. Here, the cell may be replaced with a sub-band as described below.

In addition, in the option 3-2, the "specific SCell TU #k of the plurality of SCell TUs" for the DL-HARQ reference TU may be designated as the first TU among the corresponding SCell TUs. Since DL grant DCI and DL data can be received at the same time, the HARQ-ACK reference TU can be designated as the first TU among a plurality of SCell TUs, thereby increasing the utilization efficiency of DL data transmission resources.

16 illustrates signal transmission according to option 3-2. Referring to FIG. 15, a DL grant DCI may be received in slot n of cell X (SCS: X KHz), and DL data may be received in cell Y (SCS: 4X KHz). In this case, since the SCS of the cell Y is 4X KHz, the slot n of the cell X corresponds to / aligns with four slots of the cell Y (eg, slots p to slot p + 3), and the DL data corresponds to the slot n of the cell X. It may be received after the k (eg, 2) slot based on the first slot (ie slot p) of the four slots of the cell Y. Information about k may be indicated through a DL grant DCI, and k may be an integer of 0 or more. k is set based on the pneumology used for DL data transmission (eg PDSCH transmission). Here, the DL data may be received through the PDSCH, and the DL grant DCI may be received through the PDCCH. Here, the cell may be replaced with a sub-band as described below.

Meanwhile, the proposed method of the present invention divides a single cell or carrier into a plurality of sub-bands and sets SCSs or TUs of different sizes between sub-bands, and the UE simultaneously operates or sub- The same applies to the situation in which the operation between the bands is switched. In this case, in the present invention, the cell may be replaced with a sub-band (in the cell). Here, the sub-band is composed of contiguous frequency resources (eg, contiguous plurality of RBs) and may be referred to as a bandwidth part (BWP).

17 illustrates a base station and a terminal that can be applied to the present invention.

Referring to FIG. 17, a wireless communication system includes a base station (BS) 110 and a terminal (UE) 120. When the wireless communication system includes a relay, the base station or the terminal may be replaced with a relay.

Base station 110 includes a processor 112, a memory 114, and a radio frequency (RF) unit 116. The processor 112 may be configured to implement the procedures and / or methods proposed in the present invention. The memory 114 is connected to the processor 112 and stores various information related to the operation of the processor 112. The RF unit 116 is connected with the processor 112 and transmits and / or receives a radio signal. The terminal 120 includes a processor 122, a memory 124, and a radio frequency unit 126. The processor 122 may be configured to implement the procedures and / or methods proposed by the present invention. The memory 124 is connected with the processor 122 and stores various information related to the operation of the processor 122. The RF unit 126 is connected with the processor 122 and transmits and / or receives a radio signal.

The embodiments described above are the components and features of the present invention are combined in a predetermined form. Each component or feature is to be considered optional unless stated otherwise. Each component or feature may be embodied in a form that is not combined with other components or features. It is also possible to combine some of the components and / or features to form an embodiment of the invention. The order of the operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is obvious that the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship in the claims or as new claims by post-application correction.

In this document, embodiments of the present invention have been described mainly based on a signal transmission / reception relationship between a terminal and a base station. This transmission / reception relationship is extended to the same / similarly for signal transmission / reception between the terminal and the relay or the base station and the relay. Certain operations described in this document as being performed by a base station may in some cases be performed by an upper node thereof. That is, it is obvious that various operations performed for communication with the terminal in a network including a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. A base station may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. In addition, the terminal may be replaced with terms such as a user equipment (UE), a mobile station (MS), a mobile subscriber station (MSS), and the like.

Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of a hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), FPGAs ( field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit of the invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

The present invention can be used in a terminal, base station, or other equipment of a wireless mobile communication system.

Claims (20)

1. In the method for the terminal to perform communication in a wireless communication system,

   Receiving data in time unit #n on the first frequency band; And

   Transmitting an Acknowledgment / Negative acknowledgment (A / N) for the data in time unit # m + k on a second frequency band,

   The first and second frequency bands are different from each other in the subcarrier spacing,

   Time unit #m of the second frequency band indicates a last time unit of a plurality of time units of the second frequency band corresponding to time unit #n of the first frequency band.
2. The method of claim 1,

   Each time unit comprising an equal number of orthogonal frequency division multiplexing (OFDM) -based symbols, wherein the length of each time unit is determined based on subcarrier spacing.
3. The method of claim 1,

   And the subcarrier spacing of the first frequency band is less than the subcarrier spacing of the second frequency band.
4. The method of claim 1,

   And the information regarding k is received over a control channel scheduling the data.
5. The method of claim 1,

   The wireless communication system includes a 3rd Generation Partnership Project (3GPP) -based wireless communication system.
6. In a terminal used in a wireless communication system,

   RF (Radio Frequency) module; And

   A processor, wherein the processor,

   Receive data in time unit #n on the first frequency band,

   And transmit an Acknowledgment / Negative acknowledgment (A / N) for the data in time unit # m + k on a second frequency band,

   The first and second frequency bands are different from each other in the subcarrier spacing,

   The time unit #m of the second frequency band indicates a last time unit of the plurality of time units of the second frequency band corresponding to the time unit #n of the first frequency band.
7. The method of claim 6,

   Each time unit includes the same number of orthogonal frequency division multiplexing (OFDM) -based symbols, and the length of each time unit is determined based on the subcarrier spacing.
8. The method of claim 6,

   The subcarrier spacing of the first frequency band is less than the subcarrier spacing of the second frequency band.
9. The method of claim 6,

   And the information regarding k is received through a control channel for scheduling the data.
10. The method of claim 6,

    The wireless communication system includes a 3rd Generation Partnership Project (3GPP) -based wireless communication system.
11. In the wireless communication system, a base station performs communication,

    Receiving data in time unit #n on the first frequency band; And

    Transmitting an Acknowledgment / Negative acknowledgment (A / N) for the data in time unit # m + k on a second frequency band,

    The first and second frequency bands are different from each other in the subcarrier spacing,

    Time unit #m of the second frequency band indicates a last time unit of a plurality of time units of the second frequency band corresponding to time unit #n of the first frequency band.
12. The method of claim 11,

    Each time unit comprising an equal number of orthogonal frequency division multiplexing (OFDM) -based symbols, wherein the length of each time unit is determined based on subcarrier spacing.
13. The method of claim 11,

    And the subcarrier spacing of the first frequency band is less than the subcarrier spacing of the second frequency band.
14. The method of claim 11,

    And the information regarding k is received over a control channel scheduling the data.
15. The method of claim 11,

    The wireless communication system includes a 3rd Generation Partnership Project (3GPP) -based wireless communication system.
16. A base station used in a wireless communication system,

    RF (Radio Frequency) module; And

    A processor, wherein the processor,

    Transmit data in time unit #n on the first frequency band,

    Receive an Acknowledgment / Negative acknowledgment (A / N) for the data in time unit # m + k on a second frequency band,

    The first and second frequency bands are different from each other in the subcarrier spacing,

    Time unit #m of the second frequency band indicates a last time unit of a plurality of time units of the second frequency band corresponding to time unit #n of the first frequency band.
17. The method of claim 16,

    Each time unit comprises an equal number of orthogonal frequency division multiplexing (OFDM) -based symbols, wherein the length of each time unit is determined based on subcarrier spacing.
18. The method of claim 16,

    And a subcarrier spacing of the first frequency band is smaller than a subcarrier spacing of the second frequency band.
19. The method of claim 16,

    And the information regarding k is transmitted through a control channel for scheduling the data.
20. The method of claim 16,

    The wireless communication system includes a 3rd Generation Partnership Project (3GPP) -based wireless communication system.

Images