KR101886451B1 - Methods for transmitting and receiving downlink control information and apparatuses thereof - Google Patents

Abstract

The present invention relates to a method and apparatus for transmitting and receiving downlink control information, and a method for transmitting downlink control information by a base station according to an embodiment of the present invention includes: Sub-frame scheduling information for scheduling K physical downlink shared channels (hereinafter referred to as PDSCHs) transmitted in a downlink sub-frame of a PDSCH and a HARQ related control information of the K PDSCHs Transmitting downlink control information including the downlink control information to a mobile station over a control channel; Transmitting K PDSCHs to each of the K downlink subframes according to the multiple subframe scheduling information; And receiving HARQ ACK / NACK for the K PDSCHs from the UE.

Description

[0001] The present invention relates to a method and apparatus for transmitting and receiving downlink control information,

The present invention relates to a method and apparatus for transmitting / receiving downlink control information including multiple sub-frame scheduling information and retransmission related control information of a plurality of data channels to a UE.

As communications systems evolved, consumers, such as businesses and individuals, used a wide variety of wireless terminals. The current mobile communication system such as LTE (Long Term Evolution) and LTE-Advanced of the 3GPP series is a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data beyond voice- It is required to develop a technique capable of transmitting large-capacity data in accordance with the above-described method.

Meanwhile, a new technique and a method for downlink data channel scheduling are required in a plurality of cells or a small cell.

It is an object of the present invention to provide a method and apparatus for performing multiple sub-frame scheduling, multi-TTI scheduling, or cross sub-frame scheduling in accordance with an instruction from a base station.

The present invention also provides a method and apparatus for solving the ambiguity of a retransmission procedure for a data channel when a terminal belonging to a cell / base station / RRH / antenna / RU in a small cell environment or multiple sub-frame scheduling is performed It has its purpose.

In one aspect, a method for transmitting downlink control information by a base station according to an exemplary embodiment of the present invention includes a step of transmitting K downlink control information, which is transmitted in K consecutive or non-consecutive K subframes (K is a natural number greater than 2) And transmits the downlink control information including the HARQ related control information of the K PDSCHs to the UE through the control channel. The scheduling information includes scheduling information for scheduling a physical downlink shared channel (PDSCH) Transmitting K PDSCHs to each of the K downlink subframes according to the multiple subframe scheduling information; And receiving HARQ ACK / NACK for the K PDSCHs from the UE.

In another aspect, a method for receiving downlink control information by a UE according to another embodiment of the present invention includes the steps of: receiving K physical (k) physical sub-frames transmitted in consecutive or non-consecutive K (K is a natural number greater than 2) Sub-frame scheduling information for scheduling a Physical Downlink Shared Channel (PDSCH) and downlink control information including HARQ related control information for the K PDSCHs are received from a base station through a control channel Receiving K PDSCHs from the BS in each of the K downlink subframes according to the multiple subframe scheduling information and HARQ related control information, and transmitting HARQ ACK / NACK for the K PDSCHs to the BS .

In another aspect, a base station according to another embodiment of the present invention includes K physical Downlink data channels (K) transmitted in K consecutive or non-consecutive K subframes (K is a natural number greater than 2) And transmits the downlink control information including the HARQ related control information of the K PDSCHs to the UE through the control channel, and transmits the scheduling information to the UE through the multi-subframe scheduling (PDSCH) A transmitter for transmitting K PDSCHs to the UE in each of the K downlink subframes according to information, and a receiver for receiving HARQ ACK / NACK for K PDSCHs from the UE.

In another aspect, a UE according to another embodiment of the present invention includes K physical downlink data channels transmitted in K consecutive or non-consecutive K subframes (K is a natural number greater than 2) Frame scheduling information for scheduling a shared channel (hereinafter, referred to as 'PDSCH') and downlink control information including HARQ related control information of the K PDSCHs from a base station through a control channel, And a transmitter for transmitting HARQ ACK / NACK for the K PDSCHs to the BS according to information and HARQ-related control information from the base station, K PDSCHs in each of the K downlink subframes.

When the present invention is applied, the UE can perform multiple sub-frame scheduling, multiple TTI scheduling, or cross sub-frame scheduling according to an instruction from the BS.

In particular, a terminal belonging to a small cell environment or an arbitrary cell / base station / RRH / antenna / RU has the effect of eliminating the ambiguity of a retransmission procedure for a data channel when multiple subframe scheduling is performed.

1 is a view showing a small cell development according to an embodiment.
2 is a diagram showing a small cell deployment scenario.
Figure 3 is a diagram showing a detailed scenario in the small cell deployment.
4 is a diagram illustrating a control region for transmitting a downlink control channel.
5A and 5B are diagrams showing transmission of a control channel (control region for transmitting a control channel) in one subframe.
6A and 6B are diagrams for explaining the concept of multi-subframe scheduling via PDCCH (a) / EPDCCH (b).
7 is a diagram illustrating an operation of a base station according to an embodiment of the present invention.
FIG. 8 is a diagram illustrating operations of a terminal according to another embodiment.
FIG. 9 is a diagram illustrating a configuration of a base station according to another embodiment.
10 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like. Hereinafter, the user terminal may be referred to as a terminal in the present specification. Hereinafter, the user terminal may be referred to as a terminal in the present specification.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), a transmission point (TP), a reception point It can be called another term.

In this specification, a base station or a cell is interpreted as a comprehensive meaning indicating a part or function covered by BSC (Base Station Controller) in CDMA, Node-B in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, and RU communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) a device itself providing a megacell, a macrocell, a microcell, a picocell, a femtocell, or a small cell in relation to a wireless region, or ii) the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a megacell, a macrocell, a microcell, a picocell, a femtocell, a small cell, an RRH, an antenna, an RU, a low power node (LPN), a point, an eNB, Quot;

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-Advanced, the uplink and downlink are configured on the basis of one carrier or carrier pair to form a standard. The uplink and downlink transmit control information through a control channel such as a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel (PHICH), and a Physical Uplink Control CHannel And a data channel such as a Physical Downlink Shared CHannel (PDSCH), a Physical Uplink Shared CHannel (PUSCH), and the like. On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

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

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multiplex transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiplex transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH and PDSCH are transmitted and received'.

In the following description, the description that the PDCCH is transmitted or received or the signal is transmitted or received through the PDCCH may be used to mean transmitting or receiving the EPDCCH or transmitting or receiving the signal through the EPDCCH.

The physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH. For convenience of description, the PDCCH, which is an embodiment of the present invention, may be applied to the PDCCH.

In addition, the High Layer Signaling described herein includes RRC signaling for transmitting RRC information including RRC parameters.

An eNB, which is an embodiment of a base station, performs downlink transmission to terminals. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

At this time, as described below with reference to the drawings, the first UE1 transmits the uplink signal to the eNB and the second UE transmits the uplink signal to the RRH.

The following describes a small cell deployment scenario to which the proposals described in the present invention can be applied.

1 is a view showing a small cell development according to an embodiment.

FIG. 1 shows a configuration in which a small cell and a macro cell coexist. In FIGS. 2 to 3, the presence or absence of macro coverage, whether the small cell is for outdoor use or indoor use, , Whether the development of the small cell is sparse or dense, or whether the same frequency spectrum as the macro is used in terms of spectrum or not.

2 is a diagram showing a small cell deployment scenario. Figure 2 shows a typical representative configuration for the scenario of Figure 3; Fig. 2 shows a small cell deployment scenario and includes scenarios # 1, # 2a, # 2b, and # 3. 200 represents a macro cell, and 210 and 220 represent a small cell. The overlapping macrocells in FIG. 2 may or may not exist. Coordination can be performed between the macro cell 200 and the small cells 210 and 220 and adjustment can also be performed between the small cells 210 and 220. And the overlapping regions of 200, 210, and 220 can be clustered.

Figure 3 is a diagram showing a detailed scenario in the small cell deployment.

The solid lines connecting the small cells in the small cells 312, 322, 332, and 342 refer to a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

310 shows the small cell deployment scenario # 1. Scenario 1 is a co-channel deployment scenario for small cells and macro cells in the presence of overhead macros and is an outdoor small cell scenario. Reference numeral 310 denotes a case where both the macro cell 311 and the small cell are outdoors, and 312 denotes a small cell cluster. Users are distributed both indoors / outdoors.

And 320 a small cell deployment scenario # 2a. Scenario 2a is a deployment scenario in which small cells and macros use different frequency spectra in the presence of an overlaid macro, and is an outdoor small cell scenario. Both the macro cell 321 and the small cells are outdoors and 322 indicates a small cell cluster. Users are distributed both indoors / outdoors.

And 330 a small cell deployment scenario # 2b. Scenario 2b is a deployment scenario in which the small cell and the macro use different frequency spectrum in the presence of the overlay macro and is an indoor small cell scenario. The macro cell 331 is outdoors, the small cells are all indoor, and 332 indicates a small cell cluster. Users are distributed both indoors / outdoors.

And 340 a small cell deployment scenario # 3. Scenario 3 is an indoor small cell scenario with no coverage of macros. 342 designates a small cell cluster. In addition, the small cells are all indoor and users are dispersed both indoors and outdoors.

Hereinafter, the downlink PDCCH and the DCI format will be described.

4 is a diagram illustrating a control region for transmitting a downlink control channel.

In FIG. 4, the control region 410 includes transmission of PHICH, PCFICH, and PDCCH. The control area may be composed of 1 to 3 OFDM symbols (1 to 3 OFDM symbols), but the present invention is not limited to this, and the control area may be increased or decreased depending on the situation of the system. Here, the PDCCH is allocated and transmitted evenly over the area excluding the resources in which PHICH and PCFICH are used, to the number of OFDM symbols to which the PDCCH indicated by the PCFICH is transmitted. Control signaling and cell-specific reference symbols are distributed in sub-frames.

5A and 5B are diagrams showing transmission of a control channel (control region for transmitting a control channel) in one subframe.

Referring to FIGS. 5A and 5B, 510 and 520 are examples of transmission of a PDSCH indicated by a control channel transmitted in every subframe upon transmission of a PDSCH on multiple carriers. CC # 1, # 2, and # 3 of the first, second, and third subcarriers 510 and 520 denote a first element carrier, a second element carrier, and a third element carrier, respectively. FIG. 5 is a diagram illustrating transmission of a PDSCH indicated by a control channel transmitted in each subframe upon transmission of a PDSCH on a multiple carrier. In FIG. 5, reference numeral 510 denotes an example in which no cross-carrier scheduling ), The carrier indicator is not included in the DCI (Downlink control information). The PDSCH 510 schedules the corresponding PDSCH by independently presenting a PDCCH in each carrier independently of each carrier in self carrier scheduling on multiple carriers. This results in data transmission in each carrier by a control channel transmitted in every subframe within a 1 ms subframe. 520 indicates cross carrier scheduling on multiple carriers, and a carrier indicator is included in the downlink control information. The PDSCH is scheduled to be able to be scheduled on a plurality of carriers in one carrier, and a PDSCH capable of transmitting PDCCHs existing on one carrier on a plurality of carriers is scheduled.

In the embodiment 520 as well, data transmission in multiple carriers is performed by a control channel transmitted in every subframe in a 1 ms subframe as in the case of 510.

Table 1 is a DCI format, which means a scheduling grant for uplink / downlink transmission. DCI formats are divided and transmitted according to each uplink / downlink transmission method and usage.

The scheduling information for a downlink data channel (PDSCH) received by a UE belonging to any cell / base station / RRH / antenna / RU or a small cell and an uplink data channel (PUSCH) PDCCH / EPDCCH, which is a physical control channel transmitted through a link sub-frame. In particular, as described with reference to FIG. 5, the PDSCH resource allocation information for an arbitrary UE in an arbitrary DL subframe is transmitted to the corresponding UE through the downlink PDCCH of the corresponding subframe.

However, in a small cell environment, a mobile station belonging to a small cell frequently has low mobility, so that there is a high possibility that the state of a wireless channel state with respect to a base station over time does not become significant compared with a terminal belonging to a conventional macro cell. In this case, it is not necessary to dynamically change the downlink scheduling information for PDSCH transmission such as Modulation Coding Scheme (MCS) and frequency resource allocation at the time of downlink data transmission for each subframe. In this case, as a method for reducing the control channel overhead, a downlink scheduling information (Downlink Scheduling / Assignment information) transmitted through one PDCCH or EPDCCH is used to transmit a PUSCH or a plurality of downlink subframes for a plurality of uplink subframes Multiple sub-frame scheduling, multiple transmission time interval scheduling, or cross sub-frame scheduling, which allocate PDSCHs for uplink and downlink sub-frame scheduling, are proposed.

The PDSCH having the same structure as the PDSCH scheduling information of the downlink subframe in which the downlink scheduling information for PDSCH reception of the UE is transmitted through the PDCCH or the EPDCCH is transmitted to the subsequent downlink subframe as the PDSCH resource allocation scheme, Lt; / RTI > to the terminal. That is, according to the downlink control information transmitted through one PDCCH or EPDCCH according to multiple sub-frame scheduling units, a plurality of PDSCH allocations using the same MCS can be performed in the same frequency resource. For example, when the multiple subframe scheduling units are composed of two consecutive subframes, as shown in FIG. 6, one continuous downlink control information including downlink scheduling information transmitted on the PDCCH or EPDCCH PDSCH resource allocation in two downlink subframes can be performed. For the sake of explanation, the PDSCH of the first downlink subframe is referred to as PDSCH # 1 and the PDSCH of the second downlink subframe is referred to as PDSCH # 2 in order to distinguish the two PDSCHs.

6A and 6B are diagrams for explaining the concept of multiple subframe scheduling (downlink case) via PDCCH (a) / EPDCCH (b).

Referring to FIGS. 6A and 6B, the PDSCH # 1 and the PDSCH # 2 have the same MCS and HARQ process number as the frequency resource allocation information through PDCCH (a) / EPDCCH (b).

The HARQ retransmission for the downlink data channel operates in an asynchronous adaptive manner. Therefore, PDCCH resource allocation information for retransmission is transmitted to the UE through the PDCCH / EPDCCH when retransmission is performed in the case of initial transmission failure, and the UE determines whether the PDSCH resource is retransmitted for the previous PDSCH transmission, (HARQ) process number and an NDI (New Data Indicator) field to distinguish whether it is an initial transmission for the HARQ process number.

However, when the above-described multiple sub-frame scheduling is performed, since the HARQ process numbers for PDSCH # 1 and PDSCH # 2 are the same, when retransmission is performed due to reception failure for the PDSCH # 1 or PDSCH # 2, There is no way to distinguish between retransmission and retransmission for PDSCH # 2.

The present invention relates to a method for transmitting uplink / downlink scheduling information of a UE belonging to an arbitrary cell / base station / eNB / RRH / RU in a small cell environment by using one downlink control information to transmit / And an uplink ACK / NACK feedback method and an apparatus therefor. The present invention also provides an HARQ ACK / NACK feedback method and an apparatus therefor.

In the conventional LTE / LTE-Advanced Rel-11 and below systems, a plurality of HARQ processes are supported in parallel to increase the data transmission rate between the BS and the UE. In other words, the HARQ protocol is based on a multiple parallel process. Upon receipt of a transport block for a particular HARQ process, the receiver attempts to decode the transport block and informs the transmitter as to the result of the decoding via the HARQ ACK, i. E., Whether the transport block has been successfully decoded.

In particular, in the case of downlink data transmission, a certain number of HARQ processes are supported, for example, eight HARQ processes. For this, the HARQ process number is transmitted to the UE through a DCI format for downlink allocation for PDSCH resource allocation. The DCI format for the downlink allocation includes an NDI (New Data Indicator) field as an indicator information region for distinguishing initial transmission or retransmission of new data for each HARQ process. The NDI field may be, for example, 1 bit for initial transmission, and 1 for retransmission. Accordingly, the UE can check the HARQ process number and the NDI of the corresponding PDSCH and determine whether the corresponding PDSCH is retransmitted for the data of the corresponding HARQ process or not.

Specifically, upon receiving the downlink scheduling assignment information, the UE examines the NDI to determine whether the current transmission should be soft-combined with the received data stored in the soft buffer of the corresponding HARQ process, .

The DCI format for the downlink allocation may include a redundancy version (for example, 2 bits) together with the HARQ process number of the PDSCH and the NDI. The redundancy version points to a different starting point from which the encoded bits are extracted from the circular buffer. Specifically, the outputs of the turbo encoder (systematic bits, first parity bits, second parity bits) are first interleaved. The interleaved bits enter the circular buffer. The system selects the system bits first and then the first parity bit and the second parity bit alternately once in a row.The bit selection block extracts consecutive bits from the circular buffer as much as the allocated resources.The bits to be extracted depend on the redundancy version. This redundancy version, for example, RV = 0, RV = 1, RV = 2, RV = 3 points to different starting points for extracting the encoded bits from the circular buffer.

In other words, as shown in Table 2, the BS explicitly signals HARQ related downlink control information including the HARQ process number, the NDI, and the redundancy version of the corresponding PDSCH in each downlink allocation information.

However, when the multiple sub-frame scheduling scheme is applied as described above, since a plurality of PDSCHs are allocated through one downlink allocation information, an ambiguity occurs in allocation of HARQ process numbers between the PDSCHs .

In order to solve this problem, the present invention provides HARQ related downlink control information transmission method for each PDSCH, and HARQ ACK / NACK feedback method for the UE according to the multi-subframe scheduling application.

The DCI format for downlink allocation transmits PDSCH transmission resource allocation information together with HARQ process numbers including 3 bits for FDD and 4 bits for TDD to the UE. In this specification, the case where the FDD, that is, the HARQ process number is composed of 3 bits is described as an example, but the same concept can be applied to the TDD.

Embodiment 1: Implicit HARQ process number assignment with separate ACK / NACK feedback

In the case of multiple sub-frame scheduling according to the first embodiment, the base station transmits only a single HARQ related control information (concretely, a single HARQ process number) together with a single PDSCH resource allocation information through the corresponding DL control information You can let them know. However, in this case, the UE implicitly deduces the HARQ process number of the subsequent PDSCH transmitted through the subsequent downlink subframe based on the HARQ process number transmitted through the corresponding downlink control information.

An incremental HARQ process number allocation scheme may be used as an example of the implicit HARQ process number allocation scheme. That is, as shown in FIG. 6, when allocation of PDSCH resources of two downlink subframes is performed through one downlink control information, that is, when the unit of multiple subframe scheduling is two subframes, The allocation for the two PDSCH resources is performed through the link control information. At this time, the downlink control information transmits only one HARQ related control information (specifically, HARQ process number) to the UE. The HARQ process number is used as a HARQ process number for the PDSCH # 1 transmission, which is the first PDSCH, The HARQ process number for the PDSCH # 2 in the frame may be determined as the HARQ process number + 1 of the corresponding PDSCH # 1. At this time, if the HARQ process number of the PDSCH # 1 is the maximum, it is cyclically allocated from the HARQ process number # 0 again.

Generally, k PDSCH resource allocations are performed concurrently through k < th > subframes (k is a natural number greater than 1 or 2) consecutively or discontinuously through one downlink control information PDSCHs are indexed from PDSCH # 1 to PDSCH #K according to the subframe order to be transmitted), and if the HARQ process number transmitted through the corresponding downlink control information is #m, Lt; RTI ID = 0.0 > 1 < / RTI >

In this case, the modulo 8 operation is performed in Equation (1) because the number of HARQ processes is 8. If the number of HARQ processors is x, the modulo x operation is performed.

If a different HARQ process number is implicitly assigned to each of the PDSCHs, the UE transmits independent HARQ ACK / NACK feedback (1 bit or 2 bits) to the base station for each PDSCH.

As described above, the UE implicitly deduces the HARQ process number of the subsequent PDSCH transmitted on the subsequent downlink subframe according to Equation (1) based on the HARQ process number transmitted through the corresponding downlink control information.

Accordingly, the UE can check the HARQ process number and the NDI of the corresponding PDSCH and determine whether the corresponding PDSCH is retransmitted for the data of the corresponding HARQ process or not.

That is, upon receiving the downlink multiple scheduling assignment information, the UE checks the NDI to determine whether the current downlink transmission should be soft-combined with the received data stored in the soft buffer of the corresponding HARQ process, Decide if it should be.

The UE acquires interleaved systematic bits, first parity bits, and second parity bits from the received data using the redundancy version.

As another embodiment of the implicit HARQ process number assignment, HARQ process numbers transmitted through the corresponding downlink control information are used for the first PDSCH # 1, and the HARQ process numbers used for the subsequent PDSCHs , And the HARQ process numbers of the smallest HARQ process number among the HARQ process numbers for which the PDSCH transmission is completed can be sequentially allocated. In this case, the UE also transmits independent HARQ ACK / NACK feedback (1 bit or 2 bits) to the base station for each PDSCH.

Example 2. Explicit HARQ process number assignment with separate feedback

In the second embodiment, the BS can directly allocate a separate HARQ process number for each PDSCH through the corresponding downlink control information.

The HARQ related control information includes a HARQ process number and an NDI, a redundancy version for each of the K PDSCHs.

Specifically, when the multi-subframe scheduling is performed as described above, the DL allocation DCI format includes PDSCH resource allocation information, and the HARQ process number and the NDI for each of the K PDSCHs transmitted in each subframe, And HARQ-related control information, respectively. In other words, the new downlink control information for the corresponding multiple subframe downlink allocation is transmitted to K PDSCHs according to Equation (2), together with common PDSCH scheduling information (e.g., MCS, resource block assignment, etc.) And HARQ related control information including a HARQ process number and an NDI and a redundancy version for each HARQ process number.

In this case, as in the first embodiment, the UE transmits independent HARQ ACK / NACK feedback for each PDSCH to the BS.

The UE transmits downlink control information of the DCI format including the HARQ process number and the HARQ related control information for the redundancy version, and the HARQ process number and the HARQ process number for the K PDSCHs transmitted for each subframe together with the downlink multiple scheduling assignment information PDCCH or EPDCCH from the base station.

Accordingly, the UE can check the HARQ process number and the NDI of the corresponding PDSCH and determine whether the corresponding PDSCH is retransmitted for the data of the corresponding HARQ process or not.

That is, upon receiving the downlink multiple scheduling assignment information, the UE checks the NDI to determine whether the current downlink transmission should be soft-combined with the received data stored in the soft buffer of the corresponding HARQ process, Decide if it should be.

The UE acquires interleaved systematic bits, first parity bits, and second parity bits from the received data using the redundancy version.

In the case of FDD, in the case of an uplink subframe after 4 subframes or a TDD, a corresponding subframe in which the last PDSCH is received is referred to as a downlink subframe It is possible to feed back the corresponding HARQ ACK / NACK for each codeword through the corresponding uplink subframe.

Embodiment 3. A single HARQ process number assignment with separate NDI, redundancy version and separate ACK / NACK feedback

In the third embodiment, similarly to the second embodiment, the BS allocates a single HARQ process number to a plurality of PDSCHs allocated through the corresponding downlink control information, and independently schedules NDI and redundancy versions for each PDSCH can do.

The HARQ related control information includes a common HARQ process number and a respective NDI and redundancy version for the K PDSCHs.

Specifically, when the multi-subframe scheduling is performed as described above, the downlink-allocated DCI format includes information on the NDI and the redundancy version for each of the K PDSCHs transmitted for each subframe together with the PDSCH resource allocation information . That is, the new downlink control information for the corresponding multi-subframe downlink allocation is divided into K (k) according to Equation (3) together with common PDSCH scheduling information (e.g., MCS, resource block assignment, And HARQ related control information including a respective NDI and a redundancy version for the PDSCHs.

In other words, according to the third embodiment, it is possible to independently manage HARQ procedures for additional K PDSCH transmissions through one HARQ process number.

As another form of this embodiment, the HARQ related control information may include a common HARQ process number, a common redundancy version, and each NDI for K PDSCHs. In other words, the downlink-allocated DCI format including HARQ-related control information may be defined to include a separate NDI information area for K PDSCHs transmitted for each subframe. That is, the downlink-allocated DCI format applies a single HARQ process number and redundancy version for K PDSCHs and defines a separate NDI for each PDSCH, so that the UE transmits each K number of HARQ process numbers PDSCH transmission to be managed independently.

In this case, as in the first and second embodiments, the UE transmits independent HARQ ACK / NACK feedback to the base station for each PDSCH.

Embodiment 4. Single HARQ process number assignment with single ACK / NACK feedback

In Embodiment 4, the PDSCHs allocated through the corresponding multiple sub-frame scheduling can be managed integrally through one HARQ process.

HARQ related control information includes a single HARQ process number for K PDSCHs, and includes one NDI, redundancy version in case of a single layer transmission, and a single NDI, redundancy version in case of a multi-layer transmission. Includes one or two NDI, redundancy versions, depending on the number.

Specifically, the HARQ-related control information may include a single HARQ process number configured with the same information area as the existing DCI format. Also, in case of a single layer transmission, HARQ related control information may include one NDI, redundancy version. Meanwhile, in the case of multi-layer transmission, the HARQ related control information may include one or two NDIs and redundancy versions depending on the number of codewords.

Meanwhile, the UE can feedback one or two ACK / NACKs for each codeword.

In this case, in the case of FDD, the uplink subframe after the fourth subframe or the downlink subframe in which the last PDSCH is received in the case of TDD corresponds to the downlink subframe in which the last PDSCH received through the multiple subframe scheduling is performed The HARQ ACK / NACK feedback can be defined for each codeword through the uplink sub-frame.

7 is a diagram illustrating an operation of a base station according to an embodiment of the present invention.

Referring to FIG. 7, in a method 700 of transmitting downlink control information by a base station, a base station transmits downlink control information including multiple sub-frame scheduling information and HARQ related control information to a mobile station over a control channel S710).

In step S710, the base station transmits the sub-frame scheduling information for scheduling K PDSCHs transmitted in K consecutive or non-consecutive K subframes (K is a natural number greater than 2) and HARQ related control information of K PDSCHs May be transmitted to the UE through the control channel.

In order to transmit multiple sub-frame scheduling information for scheduling K PDSCHs, the BS generates a downlink control channel including indication information for signaling the type of scheduling, and transmits the generated downlink control channel to a downlink Can be included and transmitted. Wherein the indication information indicates one of multiple TTI, multiple subframe scheduling, or crossed subframe scheduling.

In the explicit signaling method, when generating the downlink signal, the base station includes the indication information of the size of 1 bit or more in the DCI format. In the DCI format, DCI format 0 or DCI format 1a is included in the dedicated search space of the terminal so that the terminal can search in the dedicated search space. In addition, the BS may include detailed information through the RRC. The BS may include downlink control information having a size equal to or greater than 1 bit in the downlink control information, and may include multiple TTIs, multiple subframe scheduling, And RRC (Radio Resource Control) parameters including information necessary for setting any one of scheduling. In order to indicate the number of subframes, when generating a downlink signal, the RRC parameter included in the downlink signal or information indicating the number of subframes required for multi-TTI, multiple subframe scheduling, or cross subframe scheduling . Also, in order to indicate in a hybrid scheme, if the indication information is included in the RRC parameter of the downlink signal included in the downlink signal or transmitted before transmission of the downlink signal, A downlink signal indicating the number of subframes required for scheduling or cross-subframe scheduling can be generated.

The base station may include the indication information in the frequency hopping flag when the frequency hopping in the uplink signal is inactivated in the case of generating the downlink signal by the implicit signaling method, The instruction information may include the instruction information. In addition, the base station can generate a downlink signal by using the CIF so that the value of any one of 5, 6, and 7 in the CIF field is indicative information. In order to indicate the continuity of the subframe, the base station transmits the downlink signal so that the second indication, which is distinguished from the indication information or the indication information, includes continuous information of multiple subframes in multiple TTI, multiple subframe scheduling, or cross subframe scheduling. Link signal. Alternatively, the instruction information or the second instruction information may use a code point on the DCI format or a code point on the CIF.

In step S710, the BS transmits the HARQ related control information of the K PDSCHs to the UE through the control channel. At this time, the HARQ related control information may include a HARQ process number, a New-Data Indicator (NDI), and a redundancy version for the K PDSCHs.

At this time, the HARQ related control information may include a single HARQ process number for the K PDSCHs as described in the first embodiment. The HARQ process number for the PDSCH of the subframe in which the HARQ related control information is transmitted is used as the single HARQ process number and the HARQ process number for the Kth PDSCH of the K indexed subframe sequentially + K-1) modulo x (x is the number of HARQ processes). The HARQ process number for the PDSCH of the subframe in which the HARQ related control information is transmitted is used as the single HARQ process number, and the HARQ process number for the subsequent PDSCHs is the smallest HARQ process number among the HARQ process numbers May be used in turn.

Also, HARQ related control information may include a HARQ process number and an NDI, a redundancy version, for the K PDSCHs, as described in the second embodiment.

Also, HARQ related control information may include a common HARQ process number and a respective NDI and redundancy version for K PDSCHs, as described above in the third embodiment.

In addition, HARQ related control information includes a single HARQ process number for the K PDSCHs as described in Embodiment 4, and includes one NDI, redundancy version in case of a single layer transmission, multi-layer transmission, it may include one or two NDI, redundancy versions depending on the number of codewords.

Next, the BS transmits K PDSCHs to the MS (S720). In step S720, the BS may transmit K PDSCHs to each of the K downlink subframes according to the multiple subframe scheduling information. The K downlink subframes may be K consecutive or non-consecutive K subframes (K is a natural number greater than 2). The base station can transmit K PDSCHs in each of the K sub-frames, which are consecutive or non-consecutive (K is a natural number greater than 2).

Next, the base station receives HARQ ACK / NACK for the K PDSCHs from the UE (S730).

FIG. 8 is a diagram illustrating operations of a terminal according to another embodiment.

Referring to FIG. 8, in a method 800 of receiving a downlink control information by a UE, the UE receives downlink control information including multiple sub-frame scheduling information and HARQ related control information from a Node B via a control channel S810).

In step S810, the UE generates multiple sub-frame scheduling information for scheduling K PDSCHs transmitted in K consecutive or non-consecutive K subframes (K is a natural number greater than 2) and HARQ-related control information of K PDSCHs From the base station through the control channel.

In step S810, the UE receives the HARQ related control information of the K PDSCHs from the BS through the control channel. At this time, the HARQ related control information may include a HARQ process number, a New-Data Indicator (NDI), and a redundancy version for the K PDSCHs. The HARQ related control information may include a single HARQ process number for K PDSCHs or each HARQ process number for K PDSCHs as described in Embodiments 1 to 4. [ The HARQ related control information may also include a single NDI and redundancy version for the K PDSCHs or a respective NDI and redundancy version for the K PDSCHs.

Next, the terminal receives K PDSCHs from the base station (S820). In step S820, the UE can receive K PDSCHs from the BS in each of the K downlink subframes according to the multiple subframe scheduling information. The K downlink subframes may be K consecutive or non-consecutive K subframes (K is a natural number greater than 2). A UE can receive K PDSCHs in each of K consecutive or non-consecutive K subframes (K is a natural number greater than 2).

Next, the UE transmits HARQ ACK / NACK for K PDSCHs to the BS (S830).

In this case, when different HARQ process numbers are assigned to the respective PDSCHs implicitly as described in the first embodiment, the corresponding HARQ ACK / NACK feedback (1 bit or 2 bits) is generated for each PDSCH To the base station.

As described above, the UE implicitly deduces the HARQ process number of the subsequent PDSCH transmitted on the subsequent downlink subframe according to Equation (1) based on the HARQ process number transmitted through the corresponding downlink control information.

Accordingly, the UE can check the HARQ process number and the NDI of the corresponding PDSCH and determine whether the corresponding PDSCH is retransmitted for the data of the corresponding HARQ process or not.

That is, upon receiving the downlink multiple scheduling assignment information, the UE checks the NDI to determine whether the current downlink transmission should be soft-combined with the received data stored in the soft buffer of the corresponding HARQ process, Decide if it should be.

The UE acquires interleaved systematic bits, first parity bits, and second parity bits from the received data using the redundancy version.

As another embodiment of the implicit HARQ process number assignment, HARQ process numbers transmitted through the corresponding downlink control information are used for the first PDSCH # 1, and the HARQ process numbers used for the subsequent PDSCHs are not currently in use , And the HARQ process numbers of the smallest HARQ process number among the HARQ process numbers for which the PDSCH transmission is completed can be sequentially allocated. In this case, the UE also transmits independent HARQ ACK / NACK feedback (1 bit or 2 bits) to the base station for each PDSCH.

At this time, as described in the second embodiment, the UE transmits independent HARQ ACK / NACK feedback to each Node B for each PDSCH.

The UE transmits downlink control information of the DCI format including the HARQ process number and the HARQ related control information for the redundancy version, and the HARQ process number and the HARQ process number for the K PDSCHs transmitted for each subframe together with the downlink multiple scheduling assignment information PDCCH or EPDCCH from the base station.

Accordingly, the UE can check the HARQ process number and the NDI of the corresponding PDSCH and determine whether the corresponding PDSCH is retransmitted for the data of the corresponding HARQ process or not.

It is possible to independently manage the HARQ procedure for each of the additional K PDSCH transmissions through one HARQ process number as described in the third embodiment.

In this case, as in the first and second embodiments, the UE transmits independent HARQ ACK / NACK feedback to the base station for each PDSCH.

As described in Embodiment 4, the UE can feedback one or two ACK / NACKs for each codeword.

In this case, in the case of FDD, the uplink subframe after the fourth subframe or the downlink subframe in which the last PDSCH is received in the case of TDD corresponds to the downlink subframe in which the last PDSCH received through the multiple subframe scheduling is performed The HARQ ACK / NACK feedback can be defined for each codeword through the uplink sub-frame.

A method of transmitting and receiving a downlink control signal for a small cell and a cell / base station / RRH / antenna / RU under a multi-layer cell structure has been described. Hereinafter, a base station apparatus that transmits control information including a terminal apparatus using the method and corresponding scheduling information and HARQ related control information will be described.

FIG. 9 is a diagram illustrating a configuration of a base station according to another embodiment.

9, a base station 900 according to another embodiment includes a control unit 910, a transmission unit 920, and a reception unit 930.

The control unit 910 includes multiple sub-frame scheduling information and K PDSCH HARQ related control information for a UE belonging to a cell / base station / RRH / antenna / RU in a small cell environment required for performing the above- And controls the overall operation of the base station according to transmission of the downlink control information.

The transmitting unit 920 and the receiving unit 930 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

In more detail, the controller 910 generates a downlink control channel including downlink control information including multiple sub-frame scheduling information and HARQ related control information of K PDSCHs.

The transmitter 920 transmits downlink control information on the generated downlink control channel to the UE. The transmitter 920 transmits downlink control information including HARQ related control information of K PDSCHs transmitted in K consecutive or non-consecutive K subframes (K is a natural number greater than 2) And transmit K PDSCHs to the UE in each of the K downlink subframes according to the multiple subframe scheduling information.

In order to transmit the multiple sub-frame scheduling information for scheduling the K PDSCHs, the controller 910 generates a downlink control channel including indication information for signaling the kind of scheduling, and the transmitter 920 transmits downlink control channel The link control channel can be included in the downlink signal and transmitted. Where the indication information indicates either multi-TTI, multiple sub-frame scheduling or cross-sub-frame scheduling as described above.

  At this time, the HARQ related control information may include a HARQ process number, a New-Data Indicator (NDI), and a redundancy version for the K PDSCHs. The HARQ related control information may include a single HARQ process number for K PDSCHs or each HARQ process number for K PDSCHs as described in Embodiments 1 to 4. [ The HARQ related control information may also include a single NDI and redundancy version for the K PDSCHs or a respective NDI and redundancy version for the K PDSCHs.

Receiving unit 930 receives HARQ ACK / NACK for K PDSCHs from the UE.

10 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

10, a user terminal 1000 according to another embodiment includes a receiving unit 1030, a control unit 1010, and a transmitting unit 1020.

The receiver 1030 receives downlink control information, data, and messages from the base station through the corresponding channel.

In addition, the controller 1010 includes multiple sub-frame scheduling information and K PDSCH HARQ related control information for a UE belonging to a cell / base station / RRH / antenna / RU in a small cell environment required for performing the above- And controls the overall operation of the terminal according to the transmission of the downlink control information.

The transmission unit 1020 transmits uplink control information, data, and a message to the base station through the corresponding channel.

In more detail, the receiver 1030 receives downlink control information including multiple sub-frame scheduling information and HARQ related control information from a base station through a control channel. The receiving unit 1030 may receive K PDSCHs from the BS in each of the K downlink subframes according to the multiple subframe scheduling information.

The transmitter 1020 transmits HARQ ACK / NACK for K PDSCHs to the BS. The transmitting unit 1020 may transmit the HARQ ACK / NACK for the K PDSCHs to the base station by performing the step S830 described above with reference to FIG.

Although the means for transmitting the HARQ related control information and the type of the information have been described in the above embodiments, the present invention is not limited thereto. That is, the HARQ related control information may include a single HARQ process number for K PDSCHs or each HARQ process number for K PDSCHs. The HARQ related control information may include a single NDI and redundancy version for the K PDSCHs or may include a respective NDI and redundancy version for the K PDSCHs. In another example, the HARQ related control information may include a single redundancy version for the K PDSCHs and a respective NDI for the K PDSCHs.

The methods and apparatuses so far have been designed to transmit and receive downlink control information including multiple sub-frame scheduling information and HARQ related control information of K PDSCHs to a UE belonging to any cell / base station / RRH / antenna / And to a device therefor.

When multiple sub-frame scheduling is performed according to the embodiments described above, since the HARQ process numbers for the PDSCHs are the same, when retransmitting according to at least one of the corresponding PDSCHs, retransmission for a PDSCH is discriminated by the UE .

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, 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 construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (21)

A method for a base station to transmit downlink control information,
Frame scheduling information for scheduling K physical data channels transmitted in consecutive or non-consecutive K subframes (K is a natural number greater than 2) and HARQ-related control information of the K physical data channels Transmitting downlink control information to a mobile station over a control channel;
Performing HARQ ACK / NACK procedures for K physical data channels in each of the K subframes according to the multiple subframe scheduling information and HARQ related control information,
Wherein the physical data channel is a physical downlink data channel or a physical uplink data channel,
The HARQ related control information includes an HARQ process number, a New-Data Indicator (NDI), and a redundancy version for K physical data channels,
Wherein the HARQ related control information includes a single HARQ process number for calculating an HARQ process number for each of the K physical data channels,
The HARQ process number of the physical data channel of the subframe in which the HARQ related control information is transmitted is used as the single HARQ process number,
The HARQ process number for the physical data channel of the subframe indexed to the M except for the subframe in which the HARQ related control information is transmitted is (((single HARQ process number + M-1) moduler x) ,
Where x is the number of HARQ processes.
delete delete delete delete delete delete delete A method for a terminal to receive downlink control information,
Frame scheduling information for scheduling K physical data channels transmitted in consecutive or non-consecutive K subframes (K is a natural number greater than 2) and HARQ-related control information of the K physical data channels Receiving downlink control information from a base station through a control channel;
Performing HARQ ACK / NACK procedures for K physical data channels in each of the K subframes according to the multiple subframe scheduling information and HARQ related control information,
Wherein the physical data channel is a physical downlink data channel or a physical uplink data channel,
The HARQ-related control information includes an HARQ process number, an NDI (New-Data Indicator), and a redundancy version for K physical data channels,
Wherein the HARQ related control information includes a single HARQ process number for calculating an HARQ process number for each of the K physical data channels,
The HARQ process number of the physical data channel of the subframe in which the HARQ related control information is transmitted is used as the single HARQ process number,
The HARQ process number for the physical data channel of the subframe indexed to the M except for the subframe in which the HARQ related control information is transmitted is (((single HARQ process number + M-1) moduler x) ,
Where x is the number of HARQ processes.
delete delete delete delete delete delete delete delete A base station for transmitting downlink control information,
Frame scheduling information for scheduling K physical data channels transmitted in consecutive or non-consecutive K subframes (K is a natural number greater than 2) and HARQ-related control information of the K physical data channels A transmitter for transmitting downlink control information to a mobile station over a control channel; And
A controller for performing an HARQ ACK / NACK procedure for K physical data channels in each of the K subframes according to the multiple subframe scheduling information and HARQ related control information,
Wherein the physical data channel is a physical downlink data channel or a physical uplink data channel,
The HARQ-related control information includes an HARQ process number, an NDI (New-Data Indicator), and a redundancy version for K physical data channels,
Wherein the HARQ related control information includes a single HARQ process number for calculating an HARQ process number for each of the K physical data channels,
The HARQ process number of the physical data channel of the subframe in which the HARQ related control information is transmitted is used as the single HARQ process number,
The HARQ process number for the physical data channel of the subframe indexed to the M except for the subframe in which the HARQ related control information is transmitted is (((single HARQ process number + M-1) moduler x) ,
Wherein x is a number of HARQ processes.
delete A terminal for receiving downlink control information,
Frame scheduling information for scheduling K physical data channels transmitted in consecutive or non-consecutive K subframes (K is a natural number greater than 2) and HARQ-related control information of the K physical data channels A receiving unit for receiving downlink control information from a base station through a control channel; And
And a controller for performing an HARQ ACK / NACK procedure for K physical data channels in each of the K subframes according to the multiple subframe scheduling information and HARQ related control information,
Wherein the physical data channel is a physical downlink data channel or a physical uplink data channel,
The HARQ-related control information includes an HARQ process number, an NDI (New-Data Indicator), and a redundancy version for K physical data channels,
Wherein the HARQ related control information includes a single HARQ process number for calculating an HARQ process number for each of the K physical data channels,
The HARQ process number of the physical data channel of the subframe in which the HARQ related control information is transmitted is used as the single HARQ process number,
The HARQ process number for the physical data channel of the subframe indexed to the M except for the subframe in which the HARQ related control information is transmitted is (((single HARQ process number + M-1) moduler x) ,
Wherein x is a number of HARQ processes. delete

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