WO2013022267A2

WO2013022267A2 - Apparatus and method for transmitting a control channel corresponding to multiple data channels

Info

Publication number: WO2013022267A2
Application number: PCT/KR2012/006284
Authority: WO
Inventors: 홍성권
Original assignee: 주식회사 팬택
Priority date: 2011-08-10
Filing date: 2012-08-08
Publication date: 2013-02-14
Also published as: WO2013022267A3

Abstract

The present description relates to an apparatus and method for transmitting a control channel corresponding to multiple data channels. The present description discloses a method for receiving a control channel, comprising the steps of: receiving, from a transmission point, a mode indicator indicating that a physical downlink control channel corresponds to a plurality of physical downlink shared channels on a one-to-multiple basis; receiving, from the transmitting point, the plurality of physical downlink shared channels on the basis of a transmission parameter of downlink control information mapped to the physical downlink control channel; and transmitting, to the transmission point, ACK/NACK signals regarding the plurality of physical downlink shared channels. The range of a PDSCH which can be allocated to a control region of a limited resource may be expanded, and the burden on a terminal for decoding a PDCCH corresponding to each PDSCH to receive multiple PDSCHs may be alleviated.

Description

Apparatus and method for transmitting a control channel corresponding to a plurality of data channels

The present invention relates to a wireless communication system, and more particularly, to an apparatus and method for transmitting a control channel corresponding to a plurality of data channels.

In general, a wireless communication system transmits a physical downlink control channel (PDCCH) in a control region. Control information for uplink or downlink communication is mapped to a physical downlink control channel. Such control information includes resource allocation information for allocating specific radio resources to the terminal.

A radio resource may be represented as a block divided in a time-frequency plane, that is, a resource block (RB). In order to effectively use the limited radio resources, the base station performs scheduling of radio resources. The base station increases the use efficiency of radio resources through dynamic scheduling that dynamically allocates radio resources according to the amount of data to be transmitted and received, or depending on the existence of data to be transmitted and received.

Meanwhile, as the broadband communication is performed, more radio resources (resource blocks) are required, and more bits are required to transmit resource allocation information. For example, the multiple user (MU) -MIMO scheme or the coordinated multi-point transmission (CoMP) scheme requires not only basic control information but also additional control information required for operation of each scheme. More control channels are provided. However, since a radio resource assumed to be a control region is limited, a situation in which control channels overflow in the control region may occur. However, at present, a method for reducing the overflowed control channels has not been proposed.

An object of the present invention is to provide an apparatus and method for transmitting a control channel corresponding to a plurality of data channels.

Another object of the present invention is to provide an apparatus and method for receiving a control channel corresponding to a plurality of data channels.

Another technical problem of the present invention is to provide an apparatus and method for transmitting PDCCH bundling control information.

Another technical problem of the present invention is to provide an apparatus and method for transmitting PDCCH bundling control information by higher layer or lower layer signaling.

Another technical problem of the present invention is to provide an apparatus and method for performing HARQ operation on bundled PDSCHs.

According to an aspect of the present invention, a method of receiving a control channel performed by a terminal is provided. The receiving method includes receiving a mode indicator from a transmission point indicating that a physical downlink control channel is a mode capable of one-to-many correspondence with a plurality of physical downlink shared channels, downlink control mapped to the physical downlink control channel Receiving the plurality of physical downlink shared channels from the transmission point based on a transmission parameter of information, and transmitting an ACK / NACK signal for the plurality of physical downlink shared channels to the transmission point. .

According to another aspect of the present invention, there is provided a method for transmitting a control channel performed by a transmission point. The transmission method includes transmitting a mode indicator to a terminal indicating that a physical downlink control channel is a mode capable of one-to-many correspondence with a plurality of physical downlink shared channels, downlink control information mapped to the physical downlink control channel Transmitting the plurality of physical downlink shared channels to the terminal based on a transmission parameter of the terminal, and receiving an ACK / NACK signal for the plurality of physical downlink shared channels from the terminal.

According to another aspect of the present invention, a terminal for receiving a control channel is provided. The terminal receives a mode indicator from a transmission point indicating that a physical downlink control channel is a mode capable of one-to-many correspondence with a plurality of physical downlink shared channels, and receives downlink control information mapped to the physical downlink control channel. A terminal transceiver for receiving the plurality of physical downlink shared channels from the transmission point based on a transmission parameter, and transmitting an ACK / NACK signal for the plurality of physical downlink shared channels to the transmission point, and the mode indicator And a terminal processor configured to determine the plurality of physical downlink shared channels and to generate the ACK / NACK signal.

According to another aspect of the present invention, there is provided a transmission point for transmitting a control channel. The transmission point transmits a mode indicator indicating to the terminal that the physical downlink control channel is a mode capable of one-to-many correspondence with a plurality of physical downlink common channels, the downlink control information mapped to the physical downlink control channel A transmission point transceiver for transmitting the plurality of physical downlink shared channels to the terminal based on a transmission parameter, and receiving an ACK / NACK signal for the plurality of physical downlink shared channels from the terminal, and the mode indicator And a transmission point processor for generating and transmitting the transmission point to the transmission point transceiver.

The range of PDSCHs that can be allocated in the control region of limited resources can be extended, and the UE can receive one integrated PDCCH corresponding to a plurality of PDSCHs, thereby reducing the burden of decoding the PDCCHs individually. The control area can be used efficiently in the existing control area without expanding the range.

1 shows a wireless communication system to which the present invention is applied.

2 shows a structure of a radio frame to which the present invention is applied.

3 is an exemplary diagram showing a resource grid for one downlink slot to which the present invention is applied.

4 is an example of a resource allocation method to which the present invention is applied. This is type 0 resource allocation.

5 is another example of a resource allocation method to which the present invention is applied. This is a type 1 resource allocation method.

6 is another example of a resource allocation method to which the present invention is applied. This is a type 2 resource allocation method.

7 is an explanatory diagram illustrating PDCCH bundling according to an embodiment of the present invention.

8 is a flowchart illustrating a method of transmitting a control channel corresponding to a plurality of data channels according to an embodiment of the present invention.

9 is an exemplary diagram illustrating a second bit area of resource allocation information according to the present invention.

10 is a flowchart illustrating a method of transmitting a control channel corresponding to a plurality of data channels according to another embodiment of the present invention.

11 is a flowchart illustrating a method of receiving a control channel corresponding to a plurality of data channels by a terminal according to an embodiment of the present invention.

12 is a flowchart illustrating a method of transmitting a control channel corresponding to a plurality of data channels by a transmission point according to an embodiment of the present invention.

13 is a block diagram illustrating a terminal and a transmission point according to an embodiment of the present invention.

Hereinafter, some embodiments will be described in detail with reference to the accompanying drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the embodiments of the present specification, when it is determined that a detailed description of a related well-known configuration or function may obscure the gist of the present specification, the detailed description thereof will be omitted.

In addition, the present specification describes a wireless communication network, the operation performed in the wireless communication network is performed in the process of controlling the network and transmitting data in the system (for example, the base station) that is in charge of the wireless communication network, or the corresponding wireless Work may be done at the terminal coupled to the network.

According to embodiments of the present invention, 'transmitting a channel' may be interpreted as meaning transmitting information through a specific channel. Here, the channel is a concept including both a control channel and a data channel, and the control channel may be, for example, a physical downlink control channel (PDCCH) or a physical uplink control channel (PUCCH). The data channel may be, for example, a Physical Downlink Shared CHannel (PDSCH) or a Physical Uplink Shared CHannel (PUSCH).

Referring to FIG. 1, the wireless communication system 10 is widely deployed to provide various communication services such as voice and packet data. The wireless communication system 10 includes at least one base station (BS) 11. Each base station 11 provides a communication service for a particular geographic area or frequency area (generally called a cell) 15a, 15b, 15c. The cell can in turn be divided into a number of regions (called sectors).

The mobile station (MS) 12 may be fixed or mobile, and may include a user equipment (UE), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, and a PDA. (personal digital assistant), wireless modem (wireless modem), a handheld device (handheld device) may be called other terms. The base station 11 generally refers to a station that communicates with the terminal 12, and includes an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, an femto eNB, and a home. It may be referred to by other terms such as a base station (HeNB), a relay, a remote radio head (RRH), and the like. The cell should be interpreted in a comprehensive sense of a part of the area covered by the base station 11 and encompasses various coverage areas such as megacells, macrocells, microcells, picocells and femtocells.

Hereinafter, downlink refers to a communication or communication path from the base station 11 to the terminal 12, and uplink refers to a communication or communication path from the terminal 12 to the base station 11. . In downlink, the transmitter may be part of the base station 11 and the receiver may be part of the terminal 12. In uplink, the transmitter may be part of the terminal 12 and the receiver may be part of the base station 11. There is no limitation on the multiple access scheme applied to the wireless communication system 10. Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA (SC-FDMA), OFDM-FDMA, OFDM-TDMA For example, various multiple access schemes such as OFDM-CDMA may be used. The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme transmitted using different times or a frequency division duplex (FDD) scheme transmitted using different frequencies.

2 shows a structure of a radio frame to which the present invention is applied.

Referring to FIG. 2, a radio frame includes 10 subframes, and one subframe includes two slots. 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 orthogonal frequency division multiplexing (OFDM) symbols in the time domain and includes a plurality of resource blocks (RBs) in the frequency domain. The OFDM symbol is for representing one symbol period, and may be referred to as an SC-FDMA symbol or a symbol period according to a multiple access scheme.

In downlink, the preceding 1 to 3 OFDM symbols in the subframe are used as a control region to which the PDCCH is mapped, and the remaining OFDM symbols in the subframe are used as the data region to which the PDSCH is mapped. In addition to the PDCCH, the control region may be allocated a physical control format indicator channel (PCFICH). The PCFICH is transmitted in the first OFDM symbol of a subframe and carries information about the number of OFDM symbols (that is, the size of the control region) used as the control region in the subframe. The control area supports control information necessary to support communication methods such as multi-user multi-MOMO (MU-MIMO), coordinated multiple point (CoMP), carrier aggregation (CA), etc. Not enough to do

Referring to FIG. 3, each element on a resource grid is called a resource element (RE), and one resource block includes 12 * 7 resource elements. The number N _DL of resource blocks included in the downlink slot depends on the downlink transmission bandwidth set in the cell. The bandwidths considered in LTE are 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz, which are 6, 15, 25, 50, 75, and 100, respectively. At least one resource block corresponding to each band may be bundled to form a resource block group (RBG). For example, two adjacent resource blocks may constitute one resource block group.

An example of the total number of resource blocks for each bandwidth and the number of resource blocks constituting one resource block group is shown in Table 1.

Table 1

Bandwidth	Total number of resource blocks	The number of resource blocks belonging to one resource block group	Total number of resource block groups
1.4 MHz	6	One	6
3 MHz	15	2	8
5 MHz	25	2	13
10 MHz	50	3	17
15 MHz	75	4	19
20 MHz	100	4	25

Referring to Table 1, the total number of available resource blocks varies according to a given bandwidth. The difference in the total number of resource blocks means that the size of information indicating resource allocation is different. In addition, the number of cases in which resource blocks are allocated may vary depending on the resource allocation method. As an example of a resource allocation scheme, a resource block may be allocated using a bitmap format (type 0). As another example of the resource allocation scheme, resource blocks may be allocated at predetermined intervals or periods (type 1). As another example of a resource allocation scheme, resource blocks may be allocated as contiguous constant length regions (type 2). The resource block allocated to the terminal is indicated by the resource allocation information, and the bit request amount of the resource allocation information varies according to each type of resource allocation scheme and the total number of resource blocks for each bandwidth.

Referring to FIG. 4, the type 0 resource allocation method is a method of allocating the entire resource blocks of the system to the UE in units of clusters grouped into at least one consecutive resource block. At least one resource block is spaced between clusters. This is also known as non-contiguous resource allocation. If there is only one cluster, this is called Contiguous Resource Allocation, and Type 0 includes this case. Type 2 for downlink transmission is considered a case of indicating only continuous resource allocation.

In FIG. 4, a total of four clusters are allocated to the terminal. From the left, the first cluster includes one resource block, the second cluster includes three consecutive resource blocks, the third cluster includes two consecutive resource blocks, and the fourth cluster includes one resource block. The throughput of the system can vary depending on the maximum number of possible clusters allocated.

Type 0, type 1, and type 2 correspond to downlink resource allocation, and different configurations may be made for uplink resource allocation. Uplink resource allocation may be classified into type 0 and type 1 for uplink.

The uplink type 0 may use the same method as the downlink type 2. The uplink type 1 uses a cluster limited to an enumerated source encoding scheme, and a scheme of limiting to two clusters may be one example.

The allocation or unassignment of each resource block may be represented by a bitmap. Each bit is mapped to each resource block. For example, if the bit value is 0, the corresponding resource block is allocated to the terminal. If the bit value is 1, the corresponding resource block is not allocated to the terminal. For example, FIG. 4 illustrates a case where the bitmap is 010011100110100. When the resource allocation for the terminal is represented in the bitmap format as in type 0, the required amount of bits is required as many as the number of resource blocks. That is, the required amount of bits is when the number of resource blocks is n,

Becomes p represents the number of resource blocks constituting one resource block group.

Referring to FIG. 5, resource blocks are allocated in a periodic form, and resource allocation may be expressed in a form having a period of R and distributed at regular intervals for all resource blocks. For example, FIG. 5 is a case where the period R = 2. The number of bits needed to represent type 1 resource allocation is

to be. here,

Is the size of a resource block subset having a period R, and 1 is an offset. This can represent resource allocation in specific cases. In general, when type 0 and type 1 are used together, a division bit for distinguishing type 0 and type 1 may be added.

Referring to FIG. 6, the base station may allocate a cluster consisting of at least one consecutive resource block to the terminal. One cluster is represented by an offset and a length at the start of all RBs. For example, the cluster of FIG. 6 includes two resource blocks consecutive from the third resource block since the offset is 2 and the length is 2. While Type 0 and Type 1 represent non-contiguous Resource Allocation, Type 2 represents Contiguous Resource Allocation. Therefore, when the number of resource blocks is large, the number of bits of resource allocation information required to express type 2 resource allocation is smaller than that of type 0 or type 1. When n resource blocks are allocated by Type 2, the number of cases of all resource allocation is determined by Equation 1.

Equation 1

Therefore, the number of bits of the required resource allocation information is determined by equation (2).

Equation 2

Meanwhile, control information of a physical layer mapped to the PDCCH is referred to as downlink control information (hereinafter referred to as DCI). That is, DCI is transmitted on the PDCCH. DCI has different uses according to its format, and fields defined in DCI are also different. Table 2 shows DCI according to DCI format.

TABLE 2

DCI format	Explanation
0	Used for scheduling of PUSCH (Uplink Grant)
One	Used for scheduling one PDSCH codeword in one cell
1A	Used for simple scheduling of one PDSCH codeword in one cell and random access procedure initiated by PDCCH command
1B	Used for simple scheduling of one PDSCH codeword in one cell using precoding information
1C	Used for brief scheduling of one PDSCH codeword and notification of MCCH change
1D	Used for simple scheduling of one PDSCH codeword in one cell containing precoding and power offset information
2	Used for PDSCH scheduling for UE configured in spatial multiplexing mode
2A	Used for PDSCH scheduling of UE configured in long delay CDD mode
2C	Used in transmission mode 9 (multi-layer transmission)
3	Used to transmit TPC commands for PUCCH and PUSCH with power adjustment of 2 bits
3A	Used to transmit TPC commands for PUCCH and PUSCH with single bit power adjustment
4	Used for PUSCH scheduling in one uplink cell using a multi-antenna port transmission mode

Referring to Table 2, DCI format 0 indicates uplink resource allocation information, DCI formats 1 to 2 indicate downlink resource allocation information, and DCI formats 3 and 3A control uplink transmission power for arbitrary UE groups. (transmit power control (TPC)) command. Each field of the DCI is sequentially mapped to _n information bits a ₀ to a _n-1 . For example, if DCI is mapped to information bits of a total of 44 bits in length, each DCI field is sequentially mapped to a ₀ to a ₄₃ . DCI formats 0, 1A, 3, and 3A may all have the same payload size. DCI format 0 may be called an uplink grant. DCI format 2C is used for multi-layer transmission control for a single cell or a single link. That is, DCI format 2C is a DCI format used in a single cell spatial multiplexing mode. Single cell spatial multiplexing supports the transmission of multiple data streams simultaneously.

In a communication method that requires a large number of PDCCHs, such as a multiple user (MU) -MIMO scheme or an associated multiple point (CoMP) scheme, a method of expanding a control region is required. Expansion of the control region means that the control region is extended to the data region, that is, the PDSCH region, and consequently, the reduction of the PDSCH region. Therefore, as a result, since the capacity of the PDSCH region is reduced, there is a need for a method of efficiently utilizing the existing control region. Accordingly, a method of allocating resources for one or more PDSCHs at a transmitting point using one PDCCH is required. In addition, a reception point may be separately defined as a concept corresponding to a transmission point.

In downlink, a transmission point may be a component carrier, or cell, or base station (such as a macro base station, a pico base station, or a femto base station), or a remote radio head (RRH) or antenna port ( antenna port), and a reception point includes a component carrier or a cell or a terminal. In uplink, a transmission point includes a component carrier or a cell or a terminal, and a reception point is defined as a component carrier or a cell or a base station (macro base station, pico base station, femto base station, etc.), or a remote radio head or antenna port. Can be.

If the PDCCH not only indicates one PDSCH for one reception point (or terminal) but also indicates a plurality of PDSCHs, the range of PDSCHs that can be allocated in a limited resource control region can be extended. One PDCCH corresponding to two or more PDSCHs may be called PDCCH bundling, and such a PDCCH is called a bundling PDCCH. The plurality of PDSCHs corresponding to the bundling PDCCH is called a bundled PDSCH. The fact that one PDCCH corresponds to two or more PDSCHs includes that a DCI mapped to one PDCCH determines the transmission parameters of two or more PDSCHs uniformly. Transmission parameters of the PDSCH include the location and size of the resource block to which the PDSCH is transmitted, modulation and coding of the PDSCH, HARQ parameters related to PDSCH transmission. The UE may receive a plurality of PDSCHs corresponding to the bundling PDCCH with only one bundling PDCCH decoding. That is, the UE does not need to decode PDCCHs corresponding to each PDSCH in order to receive a plurality of PDSCHs, and the number of PDCCHs required for a plurality of PDSCHs is reduced. Meanwhile, the transmission point may schedule more terminals with limited resources of the control region.

Herein, the bundling PDCCH corresponds to only a plurality of PDSCHs, but the same may be applied to the uplink channel. For example, the bundling PDCCH may correspond to a plurality of PUSCHs. In the following embodiments of the present invention, the PDCCH bundling will be described based on the downlink channel. However, the technical idea may be equally applied to the uplink channel.

The bundled PDSCHs are all PDSCHs in different subframes. Therefore, in view of the dimensions of the subframe, PDCCH bundling may also be defined as one PDCCH corresponding to two or more subframes. Hereinafter, for the sake of unification of the description, an expression that the bundling PDCCH corresponds to a plurality of subframes is used. That is, in PDCCH bundling, a one-to-many mapping relationship is established between the PDCCH and the subframe. A plurality of subframes corresponding to the bundling PDCCH is called a bundled subframe.

Referring to FIG. 7, Embodiment 1 is an example of contiguous PDCCH bundling and Embodiment 2 is an example of non-contiguous PDCCH bundling. Referring to Embodiment 1, PDCCH1 in subframe # 0 corresponds to PDSCH0, PDSCH1, PDSCH2, PDSCH3, and PDSCH4 over consecutive subframes # 0, # 1, # 2, # 3, and # 4. PDCCH1 corresponds to a PDSCH of each of a plurality of consecutive subframes as a bundling PDCCH. Accordingly, the UE may receive all of the consecutive PDSCHs, that is, PDSCH0, PDSCH1, PDSCH2, PDSCH3, and PDSCH4 based on the DCI obtained by decoding PDCCH1.

Meanwhile, referring to Embodiment 2, PDCCH1 in subframe # 0 corresponds to PDSCH0, PDSCH5, and PDSCH6 over nonconsecutive subframes # 0, # 2, and # 4, respectively. That is, the bundling PDCCH corresponds to the PDSCH in discontinuous subframes. Accordingly, the UE may receive non-contiguous PDSCHs, that is, PDSCH0, PDSCH5, and PDSCH6 based on the DCI obtained by decoding PDCCH2.

As in the second embodiment, bundling in which a PDCCH exists may be performed with a short subframe period instead of a continuous subframe. A pattern indicating the presence of the PDCCH may be known to the UE in advance by higher layer signaling.

In implementing PDCCH bundling, the HARQ operation for the bundled PDSCHs must be clearly defined. As a premise of the HARQ operation, whether the HARQ parameter is commonly applied to the bundled PDSCHs or whether the HARQ parameter is independently applied to each bundled PDSCH should be defined. The HARQ parameter includes at least one of a Modulation and Coding Scheme (MCS), a new data indicator (NDI), a redundancy version (RV), and an HARQ index.

As one example, HARQ operation may be performed in common for bundled PDSCHs. In this case, the HARQ parameter of the DCI mapped to the bundled PDCCH is a common HARQ parameter applied to the bundled PDSCHs.

Assuming that the bundled PDSCHs always transmit new data, some or all of the HARQ parameters may be omitted or may have a specific value. For example, the new data indicator may be omitted, the duplicate version may be pre-qualified as set to a specific value, and the HARQ index may also be pre-qualified as set to an initial value. When implementing the HARQ operation by indicating the bundled PDSCHs to the bundling PDCCH, an overhead of control information may be reduced because the HARQ parameter is not repeatedly transmitted, and the DCI format may be concise. This is an embodiment used for the bundling PDCCH limited to the first transmission consisting of new data. This embodiment is useful in that the initial transmission represents the majority (90% or more) of the data transmission. In addition, when the DCI format mapped to the bundling PDCCH matches the size of the existing DCI format, there is an effect that the same transmission mode that defines the transmission scheme can be used.

When a common HARQ parameter is used for the bundled PDSCHs, the UE may transmit an ACK / NACK signal by any one of the following methods.

First, the UE performs an error check with a cyclic redundancy check (CRC) bit for each of the bundled PDSCHs, and then performs a logical AND operation again on the obtained result (1 for ACK and 0 for NACK), resulting in a final ACK / Outputs a NACK signal. This process is called ACK / NACK bundling. At this time, each of the bundled PDSCHs includes a CRC bit. For example, in Embodiment 1, if ACK for PDSCH1, NACK for PDSCH2, ACK for PDSCH3, and NACK for PDSCH4, then (ACK) AND (NACK) AND (ACK) AND (NACK) = NACK. Therefore, the terminal transmits a NACK signal to the base station. This is equivalent to performing a logical AND operation by collecting individual ACK / NACKs with values of ACK = 1 and NACK = 0.

Second, the UE outputs an ACK / NACK signal by performing a CRC error check after receiving all the bundled PDSCHs. In other words, the UE does not perform a CRC error check every time it receives a PDSCH, and performs a CRC error check only after receiving all of the last PDSCH. In this case, only the last PDSCH among the bundled PDSCHs may include a CRC bit. For example, in Embodiment 1, PDSCH1, PDSCH2, and PDSCH3 have no CRC bits, and only PDSCH4 includes CRC bits. In Embodiment 2, PDSCH5 and PDSCH6 do not have CRC bits, and only PDSCH7 includes CRC bits. Accordingly, the UE receives up to the last PDSCH, checks CRC errors for all bundled PDSCHs using the CRC bit of the last PDSCH, and then generates an ACK / NACK signal and transmits the result to the base station.

As such, when a plurality of PDSCHs are combined and configured to undergo one HARQ process, the HARQ parameter of the DCI mapped to the bundled PDCCH is commonly applied to the bundled PDSCHs.

Third, the terminal individually outputs and transmits an ACK / NACK signal for each of the bundled PDSCHs. That is, independent HARQ operation is performed on each of the bundled PDSCHs. This has a negative effect on the compression side of the control information, but has a gain in terms of data throughput.

As another example, HARQ operation may be performed separately for each of the bundled PDSCHs. When performing the HARQ operation by indicating the bundled PDSCHs to different separate PDCCHs, HARQ parameters are individually required and a configuration of a DCI format having a relatively large size is required. In addition, the configuration of the large size DCI format is difficult to match the size of the existing DCI format of poor control channel transmission quality.

Whether continuous or discontinuous, the bundling PDCCH corresponds to multiple subframes. Therefore, if only the application of the PDCCH bundling mode and the correspondence between the bundling PDCCH and the plurality of subframes (or bundled PDSCHs) can be known, the UE may receive a plurality of PDSCHs based on one bundling PDCCH. Can be. The PDCCH bundling mode refers to an operation mode of a terminal or a base station in which one bundling PDCCH corresponds to a plurality of subframes (or a plurality of PDSCHs). Information indicating that the PDCCH bundling mode is applicable is called a mode indicator. In other words, the mode indicator indicates that the PDCCH is a mode capable of one-to-many correspondence with a plurality of PDSCHs. Information providing a correspondence between the bundling PDCCH and a plurality of subframes (or a plurality of PDSCHs) is referred to as bundling information. Here, the correspondence is a concept that includes the number of subframes corresponding to the bundling PDCCH, the number of subframes corresponding to the bundling PDCCH, and the like.

Referring to FIG. 8, the transmission point transmits PDCCH bundling control information to the terminal (S800). As an example, the PDCCH bundling control information includes a mode indicator or a bundling length indicator or corresponding information or a bundling flag. As another example, the PDCCH bundling control information includes a mode indicator and a bundling length indicator. As another example, the PDCCH bundling control information includes a mode indicator and a bundling flag. As another example, the PDCCH bundling control information includes a bundling length indicator and a bundling flag. As another example, the PDCCH bundling control information includes a mode indicator, a bundling length indicator, and a bundling flag. As another example, the PDCCH bundling control information includes a mode indicator and corresponding information. As another example, the PDCCH bundling control information includes a bundling length indicator and corresponding information. As another example, the PDCCH bundling control information includes a bundling flag and corresponding information. As another example, the PDCCH bundling control information includes a mode indicator, a bundling length indicator, and corresponding information. As another example, the PDCCH bundling control information includes a mode indicator, corresponding information, and a bundling flag. As another example, the PDCCH bundling control information includes a bundling length indicator, corresponding information, and a bundling flag. As another example, the PDCCH bundling control information includes all of a mode indicator, a bundling length indicator, corresponding information, and a bundling flag.

The mode indicator is information indicating whether the UE should operate in the PDCCH bundling mode. The bundling length indicator is information indicating the number of bundled subframes corresponding to the bundling PDCCH. The correspondence information is information indicating a correspondence between the value of the bundling length indicator and the number of bundled subframes. The mode indicator, the bundling length indicator, and the corresponding information may be transmitted at different timings. In particular, the correspondence information may be transmitted to the terminal in advance together with the mode indicator as an RRC message which is higher layer signaling.

Since the bundling length indicator may be changed instantaneously, the bundling length indicator may be transmitted to the terminal more dynamically than the mode indicator or the corresponding information. This is because when the number of bundled subframes most suitable for each communication environment changes over time, the bundling length indicator must change accordingly.

For example, if a mode indicator indicating that the terminal should operate in the PDCCH bundling mode and the corresponding information is transmitted first, the terminal is first set to the PDCCH bundling mode. Thereafter, when the terminal receives the bundling length indicator, the terminal may receive the bundled PDSCHs at that time. According to an embodiment, all of the mode indicator, corresponding information, and bundling length indicator among the PDCCH bundling information may be used, or only some of them may be used. Hereinafter, an embodiment of each PDCCH bundling control information will be described.

As an example, the PDCCH bundling control information includes a mode indicator and corresponding information, and both the mode indicator and the corresponding information are generated at a medium access control (MAC) or radio resource control (RRC) layer level. It may be a higher layer message. Since the signaling delay is relatively long when the mode indicator and the corresponding information are higher layer messages, the PDCCH bundling may operate statically or semi-statically. The transmission point may indicate whether the UE is in the PDCCH bundling mode by using a mode indicator that is a higher layer message. For example, the mode indicator is 1 bit. If the value is 1, the mode indicator may indicate application of the PDCCH bundling mode, and if the value is 0, the mode indicator may indicate non-application of the PDCCH bundling mode. Here, when the mode indicator is 1, the number of bundled subframes is determined by the corresponding information as shown in Table 3.

TABLE 3

Mode indicator	Explanation
0	-Not in PDCCH bundling mode
One	-PDCCH bundling mode-the number of bundled subframes is indicated in the corresponding information

Referring to Table 3, if the mode indicator is 0, this indicates a non-PDCCH bundling mode. On the other hand, a mode indicator of 1 indicates a PDCCH bundling mode and means that the number of bundled subframes is indicated by corresponding information. Therefore, in this case, the bundling length indicator may not be necessary separately.

If the transmission point indicates to the UE by correspondence information that n subframes correspond to one bundling PDCCH, the UE can know that the DCI mapped to the bundling PDCCH corresponds to n bundled PDSCHs. That is, if the UE receives the bundling PDCCH after the setting of the PDCCH bundling mode is completed by the higher layer message such as the mode indicator and the corresponding information, the terminal bundles the number of bundles set by the higher layer message from the subframe at this point in time. Bundled PDSCHs are received using the bundled PDCCH during subframes. The bundling PDCCH transmitted after the setting of the bundling mode is completed may have the same length and format as the normal PDCCH, and an additional bit allocation is made for the general PDCCH or the same length as the general PDCCH, but some bitfields have been changed. It may be in the form. At this time, during the bundled subframe, a separate bundling PDCCH for the UE may be transmitted or may not be transmitted. The separate bundling PDCCH may be transmitted, for example, for the bundled PUSCH separately from the bundled PDSCH.

If a separate bundling PDCCH is not transmitted, the UE may not perform PDCCH blind decoding. However, after the bundled subframes have elapsed, the UE may start performing blind decoding to receive the bundled PDCCH again. In this case, the PDCCH bundling mode already set by the higher layer signaling is applied as it is. When the bundling PDCCH is received, the bundled PDSCHs are received during the bundled subframe from that point in time.

As another example, the PDCCH bundling control information includes all of the mode indicator, the corresponding information, and the bundling length indicator. In this case, the mode indicator and the corresponding information may be an upper layer message, and the bundling length indicator may be lower layer information. This is to compensate for the static signaling when the PDCCH bundling information is all higher layer messages. The mode indicator may be specifically signaled to the UE so that the UE is set to the PDCCH bundling mode, and the number of bundled subframes may be dynamically indicated by the bundling length indicator. At this time, the bundling length indicator is included in the DCI mapped to the bundling PDCCH. For example, the DCI including the bundling length indicator may be a DCI of a new format.

If the bundling length indicator is 1 bit, a value of 0 indicates that the bundling PDCCH is applied to only one subframe as before, and a value of 1 indicates a number of bundles determined by higher layer signaling (ie, corresponding information). This indicates that the bundling PDCCH continues to be applied as many as the subframe. When the bundling length indicator is 2 bits, the correspondence between the value of the bundling length indicator and the number of bundled subframes is indicated by the corresponding information as shown in Table 4 below.

Table 4

Bundling Length Indicator	Explanation
00	Number of bundled subframes = 1
01	Number of bundled subframes = 2
10	Number of bundled subframes = 4
11	Number of bundled subframes = 8

Referring to Table 4, if the bundling length indicator is 00, this indicates that the number of bundled subframes is one. That is, the bundling PDCCH corresponds only to a subframe including the bundling PDCCH. Even in the PDCCH bundling mode by the mode indicator, there is substantially no bundled subframe. On the other hand, if the bundling length indicators are 01, 10, and 11, this means that the number of bundled subframes is 2, 4, and 8, respectively.

When the bundling length indicator is 3 bits, the corresponding information may be defined as shown in the following table.

Table 5

Bundling Length Indicator	Scheduling	Explanation
000	Downlink scheduling (bundled PDSCHs)	Number of bundled subframes = 1
001	Downlink scheduling (bundled PDSCHs)	Number of bundled subframes = 2
010	Downlink scheduling (bundled PDSCHs)	Number of bundled subframes = 4
011	Downlink scheduling (bundled PDSCHs)	Number of bundled subframes = 8
100	UPlink scheduling (bundled PUSCHs)	Number of bundled subframes = 1
101	UPlink scheduling (bundled PUSCHs)	Number of bundled subframes = 2
110	UPlink scheduling (bundled PUSCHs)	Number of bundled subframes = 4
111	UPlink scheduling (bundled PUSCHs)	Number of bundled subframes = 8

Referring to Table 5, the bundling length indicator indicates not only the number of bundled subframes, but also whether a channel corresponding to a bundling PDCCH is a bundled PDSCH or a bundled PUSCH. For example, if the bundling length indicator is 000, this indicates that the PDCCH bundling mode is not. If the bundling length indicators are 000, 001, 010, and 011, this indicates that the PDCCH bundling mode is used in downlink scheduling, and that the number of bundled subframes is 1, 2, 4, and 8, respectively. At this time, the bundled PDSCHs correspond to the bundled PDCCH. When the bundling length indicators are 100, 101, 110, and 111, this indicates a PDCCH bundling mode in uplink scheduling, and means that the number of bundled subframes is 1, 2, 4, and 8, respectively. At this time, the bundled PUSCHs correspond to the bundled PDCCH. The mapping relations regarding the values of the bundling length indicators shown in Table 5 and the number of subframes indicated by the values are transmitted to the terminal as corresponding information.

When the indication of the bundling length indicator is defined by the corresponding information as the higher layer message as shown in Tables 3 to 5, the number of bundled subframes may be dynamically changed using the bundling length indicator as the lower layer information. This may compensate for the PDCCH bundling which is not dynamic when both the corresponding information and the bundling length indicator are upper layer messages.

As another example, the PDCCH bundling control information includes a mode indicator and a bundling flag. In this case, the bundling length indicator and the corresponding information may not be separately defined or used. The mode indicator is an upper layer message, and the bundling flag is lower layer information generated at the physical layer level. When the bundling flag is lower layer information, since the signaling delay is relatively short, the PDCCH bundling may operate dynamically. In the case where the bundling flag is lower layer information, a DCI format including the bundling flag may be newly defined. For example, the bundling flag is 1 bit and may be defined as shown in the following table.

Table 6

Bundling Flag	Explanation
0	Current subframe is not in PDCCH bundling mode
One	The current subframe is in PDCCH bundling mode

Referring to Table 6, the bundling flag indicates a state change by toggling its value from 0-> 1 or from 1-> 0. For example, the bundling flag defines whether or not the current subframe is in PDCCH bundling mode. If the bundling flag is 0, it indicates that the current subframe is a subframe in which PDCCH bundling is not applied (that is, it is not PDCCH bundling mode). If the bundling flag is 1, it indicates that the subframe is applied to PDCCH bundling from the current subframe. (Ie, in PDCCH bundling mode). After the bundling flag is set to 1, the UE recognizes that the bundling subframe continues until the PDCCH having the bundling flag = 0 is received again. In this case, the transmission point may not transmit a separate bundling PDCCH including a bundling flag = 1 in every subframe.

For example, the value of the bundling flag in the PDCCH of each subframe is 0-> 1-> x-> x-> over subframe # 0-> # 1-> # 2-> # 3-> # 4. Let's say zero. Here, x indicates that a PDCCH including a bundling flag is not transmitted. In subframe # 0, not PDCCH bundling mode, but subframes # 1 to # 3 are PDCCH bundling mode. Therefore, the PDCCH transmitted in subframe # 1 corresponds to the subframes # 1, # 2, and # 3 as the bundling PDCCH. Since a bundling flag having a value of 0 is transmitted in subframe # 4, PDCCH bundling is terminated. The PDCCH including the bundling flag of 0 in subframe # 4 may be used only for indicating that the bundling flag is changed to 0 or may be used for other purposes than the transfer of the bundling flag value. For example, resource allocation and other control information as in previous bundling or new resource allocation and other control information may be transmitted. UE decodes the PDCCH of a subframe and then analyzes the bundling flag to know whether the corresponding subframe is applied to the PDCCH bundling mode. By using the bundling flag, the start and end of the PDCCH bundling can be dynamically indicated to the UE.

As another example, the PDCCH bundling control information may include a mode indicator, and the mode indicator may be lower layer information. The method of semi-persistent scheduling (SPS) may be readjusted specifically for the PDCCH bundling mode. Ring-less scheduling is a manner in which scheduling through one activation signaling continues until release signaling is received. Here, the application of the PDCCH bundling mode corresponds to the activation of the ring scheduling, and the non-application of the PDCCH bundling mode corresponds to the release of the ring scheduling. At this time, the identifier scrambled on the PDCCH may be a Cell-Radio Network Temporary Identifier (SPS-C-RNTI). The DCI mapped to the bundling PDCCH has two forms depending on the activation or deactivation of the ring scheduling. The table below is defined for activation / release for SPS but can be utilized to indicate the application of bundling PDCCH mode. That is, in the SPS scheme, PDCCH bundling can be implemented by adjusting the period in which the SPS PDCCH can be transmitted from one large existing value (at least 10 subframes) to one subframe.

TABLE 7

DCI Field	DCI format	0	DCI format 1 / 1A	DCI format	2 / 2A / 2B
Transmit Power Control Command for Scheduled PUSCH	Set to '00'	N / A	N / A
Cyclic Shift for Demodulation Reference Signals	Set to '000'	N / A	N / A
Modulation and Coding Schemes and Iterative Versions	MSB is set to '0'	N / A	N / A
HARQ process number	N / A	FDD: set to '000' TDD: set to '0000'	FDD: set to '000' TDD: set to '0000'
Modulation and Coding Scheme	N / A	MSB is set to '0'	MSB is set to 0 for possible transport blocks
Repeat version	N / A	Set to '00'	Set to 00 for a possible transport block

Referring to Table 7, it can be seen that a value of a specific field is set to a specific value according to the DCI format. For example, in DCI format 0, the 2-bit field for the TPC command is set to '00', and the 3-bit field for the cyclic shift DM RS is set to '000', and the modulation and coding scheme and iteration version (Modulation and coding). The MSB is set to zero in a 5-bit field for scheme and redundancy version. When each field receives the DCI format 0/1 / 1A / 2 / 2A / 2B set as shown in Table 5, the UE may recognize that the received DCI is a DCI applying the PDCCH bundling mode. Accordingly, the UE operates according to PDCCH bundling. At this time, the period of the ring scheduling specified by the higher layer message is set short.

Meanwhile, the DCI set to indicate non-application of the PDCCH bundling mode is also set differently according to the format. This is illustrated in the following table.

Table 8

DCI Field	DCI format	0	DCI format 1A
Transmit Power Control Command for Scheduled PUSCH	Set to '00'	N / A
Cyclic Shift for Demodulation Reference Signals	Set to '000'	N / A
Modulation and Coding Schemes and Iterative Versions	Set to '11111'	N / A
Resource block allocation and hopping resource allocation	All set to '1'	N / A
HARQ process number	N / A	FDD: set to '000' TDD: set to '0000'
Modulation and Coding Scheme	N / A	Set to '11111'
Repeat version	N / A	Set to '00'

Referring to Table 8, it can be seen that the value of a specific field is set to a specific value according to the DCI format. For example, in DCI format 0, the 2-bit field for the TPC command is set to '00', and the 3-bit field for the cyclic shift DM RS is set to '000', and the modulation and coding scheme and iteration version (Modulation and coding). The 5-bit fields for the scheme and redundancy version are all set to one. When each field receives the DCI format 0 or 1A set as shown in Table 6, the UE may recognize that the received DCI is a DCI indicating the non-application of the PDCCH bundling mode. Accordingly, the UE releases the PDCCH bundling mode. The UE has a burden of continuously blind decoding the PDCCH in order to determine whether the current subframe is a subframe in which the PDCCH bundling mode is released.

As another example, the ring scheduling activation may be applied as it is. For example, a PDCCH bundling operation may be performed by maintaining a ring scheduling scheme but using a mode indicator or a bundling flag together. In this case, the effect in terms of PDCCH misdetection probability may be increased.

The UE checks whether the PDCCH bundling mode is applied from the mode indicator (S805). In step S805, it is determined whether the PDCCH bundling mode is applied. If the PDCCH bundling mode is already applied between the UE and the transmission point, the determination of the PDCCH bundling mode is unnecessary, so steps S800 and S805 may be omitted. If it is confirmed that the PDCCH bundling mode is applied, the UE determines the bundled subframes based on the PDCCH bundling control information (eg, at least one of corresponding information, a bundling length indicator, and a bundling flag) (S810). The terminal receives the bundled PDSCHs in the bundled subframes using the DCI mapped to the bundling PDCCH (S815). Upon receiving the bundled PDSCH, the terminal performs an HARQ operation as described in FIG. 7 and transmits an ACK / NACK signal to a transmission point (S820).

In step S805, if the PDCCH bundling mode is not applied, the UE decodes the PDCCH in a subframe and receives the PDSCH in the subframe according to the indication of the decoded PDCCH. Upon receiving the PDSCH, the terminal transmits an ACK / NACK signal to the transmission point according to the existing HARQ operation.

When considering a DCI of a new format including a bundling length indicator or a bundling flag as described above for PDCCH bundling, a burden of blind decoding of a UE may be increased. Accordingly, there is a need for a method of maintaining the DCI format as it is, but using a certain constraint so that the DCI format includes a bundling length indicator or a bundling flag.

10 is a flowchart illustrating a method of transmitting a control channel corresponding to a plurality of data channels according to another embodiment of the present invention. Each step of FIG. 10 may be included in step S800 of FIG. 8 or performed before it.

Referring to FIG. 10, the base station sets a restriction on resource allocation for the PDSCH (S1000). Restriction of resource allocation may mean limiting a pattern of resource blocks allocated to the terminal. Alternatively, limiting resource allocation may mean reducing the degree of freedom to which resource blocks are allocated. Alternatively, limiting resource allocation may mean reducing the number of resource blocks allocated to the terminal. Alternatively, limiting resource allocation may mean increasing the number of resource blocks included in the resource block group. Restriction of resource allocation may be set in a communication environment in which a large number of terminals exist while mainly requiring less resources (or bandwidth), such as a voice call. In this case, the cluster length does not have to be large in consecutive resource allocation.

As an example, in a resource allocation such as type 2, the base station may set the maximum length of the cluster not to exceed k. Where k ≦ N _RB . N _RB is the maximum number of resource blocks allocable to the terminal according to the system bandwidth. Alternatively, the base station may set the maximum length of the cluster not to exceed N _RB / 2. DCI supported with continuous resource allocation may be Format 0 or Format 1A.

According to the continuous resource allocation, a cluster consisting of at least one resource block is allocated to the terminal. One cluster may be represented by an offset and a length, and the offset and the length may have a variable value. The number of all cases of clusters that can be represented by various offsets and lengths can be obtained by Equation 1 above.

For example, in case of allocating 100 resource blocks to a terminal by consecutive resource allocation, the number of all cases of the cluster that can be represented is 5050 according to Equation (1). Resource allocation information should be able to represent all 5050 cases. Therefore, the number of bits needed for resource allocation information

Bit, that is, 13 bits. However, if the base station limits the cluster length to 1, each of the 100 resource blocks becomes one cluster. At this time, each cluster may be specified by the size of the offset. That is, the number of all cases of the cluster that can be represented is 100. If an index is assigned to each cluster, the index has a value from 0 to 99. 100 indexes may be represented by 7 bits. Accordingly, 13-7 = 6 bits in the resource allocation information can be used as the PDCCH bundling control information. If the base station restricts the length of the cluster to 2, the number of all cases of the cluster that can be represented is 199, and when expressed as an index, 0 to 198. These indices can be represented by 8 bits. In this case, 13-8 = 5 bits in the resource allocation information can be used as the PDCCH bundling control information.

As another example, in a resource allocation such as type 0, the base station may limit the maximum number of clusters not to exceed m. For example, when 100 resource blocks are allocated in units of 25 resource block groups (RBGs) in a 20 MHz band, 25 bits of resource allocation information are required. At this time, up to 13 clusters may be allocated. If the maximum number of assignable clusters is reduced to six, the number of bits required is 23 in total as shown in Equation 3 below.

Equation 3

Therefore, 25-23 = 2 bits in the resource allocation information can be used as the PDCCH bundling control information. Here, a discontinuous resource allocation algorithm using uplink enumerated source coding may be applied to express resource allocation by type 0.

If the length of the cluster is basically already limited to the predetermined length by the communication protocol, the procedure of step S1000 may be omitted.

The base station divides the resource allocation information into a first bit region and a second bit region as shown in FIG. 9, sets the first bit region to an index value of a specific resource allocation, and controls the PDCCH bundling of the second bit region of the resource allocation field. Information is set (S1005). That is, the second bit area does not represent resource allocation and is used for a purpose different from resource allocation.

The number of bits in the second bit area may vary depending on the degree of limitation of resource allocation.

For example, in the resource allocation of type 0, if the cluster length is limited to 2, as described above, the index is 199 in total and can be represented by 8 bits. If the resource allocation field is 8 bits or more, the base station sets 8 bits, which is the least significant bit, as the first bit area, and divides the most significant bit (MSB) bit area exceeding the 8 bits into the second bit area. Can be. If the resource allocation field is 13 bits, 8 bits are the first bit area and the remaining 5 bits are the second bit area. Of course, the first bit region may include the MSB and the second bit region may include the LSB.

The base station attaches the CRC bit obtained from the DCI including the resource allocation field divided into the first bit region and the second bit region to the DCI (S1010). The CRC bit is calculated by substituting the information bits constituting the DCI into cyclic generator polynomials. Here, the specific value preset in the second bit area is reflected in the calculation of the CRC bit.

The transmission point scrambles the specific RNTI in the CRC bit (S1015), maps the DCI to which the specific RNTI is scrambled CRC bit to the bundling PDCCH, and transmits the bundling PDCCH to the UE (S1020). Here, scrambling may be referred to as masking.

Referring to FIG. 11, the terminal receives PDCCH bundling control information from a transmission point (S1100). According to an embodiment, the PDCCH bundling information may include any one or all combinations of a mode indicator, corresponding information, a bundling length indicator, and a bundling flag. The embodiment described in FIG. 8 may be applied to the embodiment of the PDCCH bundling information. On the other hand, with respect to which layer of the PDCCH bundling information is a message, there are the following embodiments.

As an example, all of the PDCCH bundling control information may be higher layer messages.

As another example, all of the PDCCH bundling control information may be lower layer information. In this case, the PDCCH bundling control information is included in the DCI mapped to the bundling PDCCH. In operation S1100, the UE receiving the PDCCH bundling control information includes blind decoding on the bundling PDCCH. Blind decoding may be called descrambling. Blind decoding is a decoding method that defines a constant decoding start point in a predetermined control region, performs decoding on all possible DCI formats in a given transmission mode, and distinguishes a user from specific RNTI information scrambled in CRC bits. For example, blind decoding includes performing a XOR operation on a specific RNTI in the CRC bit of the DCI received by the UE.

As another example, the PDCCH bundling control information may be divided into an upper layer message and lower layer information. For example, the mode indicator and the corresponding information may be an upper layer message, and the bundling length indicator and the bundling flag may be lower layer information. The bundling length indicator or the bundling flag is included in the DCI mapped to the bundling PDCCH, and the indication of the bundling length indicator may be defined as shown in Tables 3 to 5 based on corresponding information, for example. The DCI mapped to the bundling PDCCH may include a bundling length indicator or a bundling flag as a new field, or may be configured as a second bit area of resource allocation information. Herein, in operation S1100, the UE receiving the PDCCH bundling control information includes blind decoding on the bundling PDCCH.

The UE checks whether the PDCCH bundling mode is applied from the mode indicator (S1105). Step S1105 is a step of determining whether to apply the PDCCH bundling mode. In the case where the PDCCH bundling mode is already applied between the UE and the transmission point, steps S1100 and S1105 may be omitted since the determination of the PDCCH bundling mode is unnecessary. If it is confirmed that the PDCCH bundling mode is applied, the UE determines the bundled subframes based on the corresponding information, the bundling length indicator, and / or the bundling flag (S1110). The terminal receives the bundled PDSCHs in the bundled subframes using the DCI mapped to the bundling PDCCH (S1115). Upon receiving the bundled PDSCH, the terminal performs an HARQ operation as described in FIG. 7 and transmits an ACK / NACK signal to a transmission point (S1120).

In step S1105, if the PDCCH bundling mode is not applied, the UE decodes the PDCCH in the subframe and receives the PDSCH in the subframe according to the indication of the decoded PDCCH (S1125). Upon receiving the PDSCH, the terminal transmits an ACK / NACK signal to the transmission point according to the existing HARQ operation (S1120).

Referring to FIG. 12, the transmission point transmits PDCCH bundling control information to the terminal (S1200). According to an embodiment, the PDCCH bundling information may include any one or all combinations of a mode indicator, corresponding information, a bundling length indicator, and a bundling flag. The embodiment described in FIG. 8 may be applied to the embodiment of the PDCCH bundling information. On the other hand, with respect to which layer of the PDCCH bundling information is a message, there are the following embodiments.

As another example, all of the PDCCH bundling control information may be lower layer information. In this case, the PDCCH bundling control information may be included in the DCI mapped to the bundling PDCCH and transmitted.

As another example, the PDCCH bundling control information may be divided into an upper layer message and lower layer information. For example, the mode indicator and the corresponding information may be an upper layer message, and the bundling length indicator and the bundling flag may be lower layer information. The bundling length indicator or the bundling flag is included in the DCI mapped to the bundling PDCCH, and the indication of the bundling length indicator may be defined as shown in Tables 3 to 5 based on corresponding information, for example. The DCI mapped to the bundling PDCCH may include a bundling length indicator or a bundling flag as a new field, or may be configured as a second bit area of resource allocation information.

The transmission point transmits the bundled PDSCHs to the UE in the number of bundled subframes set according to the corresponding information, the bundling length indicator, and / or the bundling flag (S1205). At this time, the transmission parameters of the bundled PDSCHs are uniformly determined by the DCI mapped to the bundling PDCCH.

The transmission point receives an ACK / NACK signal from the terminal based on the HARQ operation as described in FIG. 7 (S1210).

Referring to FIG. 13, the terminal 1300 includes a terminal transceiver 1305 and a terminal processor 1310. The transmission point 1350 includes a transmission point processor 1355 and a transmission point transceiver 1360.

The transmission point processor 1355 generates PDCCH bundling control information and sends the same to the transmission point transceiver 1360. According to an embodiment, the PDCCH bundling information may include any one or all possible combinations of a mode indicator, corresponding information, a bundling length indicator, and a bundling flag. The embodiment described in FIG. 8 may be applied to the embodiment of the PDCCH bundling information.

As an example, all of the PDCCH bundling control information may be higher layer messages. As another example, all of the PDCCH bundling control information may be lower layer information. In this case, the transmission point transceiver 1360 may include PDCCH bundling control information in a DCI mapped to the bundling PDCCH and transmit the same. As another example, the PDCCH bundling control information may be divided into an upper layer message and lower layer information. For example, the mode indicator and the corresponding information may be an upper layer message, and the bundling length indicator and the bundling flag may be lower layer information. The transmission point transceiver 1360 includes a bundling length indicator or a bundling flag in a DCI mapped to the bundling PDCCH, and the bundling length indicator is defined as shown in Tables 3 to 5 based on corresponding information, for example. Can be. The transmission point transceiver 1360 may include a bundling length indicator or a bundling flag as a new field in the DCI mapped to the bundling PDCCH, or may configure the second bit area of the resource allocation information.

The transmission point transceiver 1360 transmits the PDCCH bundling control information to the terminal 1300. In addition, the transmission point transceiver 1360 transmits the bundled PDSCHs to the UE 1300 in the number of bundled subframes set according to the corresponding information, the bundling length indicator, and / or the bundling flag. At this time, the transmission parameters of the bundled PDSCHs are uniformly determined by the DCI mapped to the bundling PDCCH.

The terminal transceiver 1305 receives the PDCCH bundling control information from the transmission point 1350. At this time, the operation of the UE transceiver 1305 to receive the PDCCH bundling control information includes blind decoding on the bundling PDCCH.

The terminal processor 1310 checks whether the PDCCH bundling mode is applied from the mode indicator. However, when the PDCCH bundling mode is already applied between the terminal 1300 and the transmission point 1350, the determination of the PDCCH bundling mode is unnecessary, and thus the terminal processor 1310 may not perform the checking process. . Upon confirming that the PDCCH bundling mode is applied, the terminal processor 1310 determines the bundled subframes based on the corresponding information.

The UE transceiver 1305 receives the bundled PDSCHs in the bundled subframes using the DCI mapped to the bundling PDCCH. Upon receiving the bundled PDSCH, the terminal processor 1310 generates an ACK / NACK signal by performing an HARQ operation as described in FIG. 7 and transmits the ACK / NACK signal to the terminal transceiver 1305. The ACK / NACK signal is transmitted to the transmission point 1350.

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

Claims

In the method of receiving a control channel performed by a terminal,

Receiving a mode indicator from a transmission point indicating that a physical downlink control channel is in a one-to-many mode corresponding to a plurality of physical downlink shared channels;

Receiving, from the transmission point, downlink control information mapped to the physical downlink control channel and including downlink transmission parameters for the plurality of physical downlink shared channels;

Receiving the plurality of physical downlink shared channels from the transmission point based on the transmission parameter; And

And transmitting an ACK / NACK signal for the plurality of physical downlink shared channels to the transmission point.
The method of claim 1,

And the mode indicator is included in a higher layer message generated in a higher layer.
The method of claim 1,

Receiving from the transmission point a bundling length indicator indicating the number of the plurality of physical downlink shared channels,

And the bundling length indicator is included in the downlink control information.
The method of claim 1,

And a cyclic redundancy check (CRC) bit is added only to the last received one of the plurality of physical downlink shared channels.
The method of claim 1,

In the case where the mode indicator indicates that the physical downlink control channel is a mode capable of one-to-many correspondence with the plurality of physical downlink shared channels,

The downlink control information further includes a bundling flag indicating whether the physical downlink control channel currently corresponds to the plurality of physical downlink shared channels one-to-many. How to receive.
In the transmission method of the control channel performed by the transmission point,

Transmitting a mode indicator to the terminal indicating that the physical downlink control channel is a mode capable of one-to-many correspondence with a plurality of physical downlink shared channels;

Transmitting downlink control information mapped to the physical downlink control channel and including downlink control information for the plurality of physical downlink shared channels, to the terminal;

Transmitting the plurality of physical downlink shared channels to the terminal based on the transmission parameter; And

And receiving an ACK / NACK signal for the plurality of physical downlink shared channels from the terminal.
The method of claim 6,

And the mode indicator is included in an upper layer message generated in an upper layer.
The method of claim 6,

The method may further include transmitting a bundling length indicator indicating the number of the plurality of physical downlink shared channels to the terminal.

And the bundling length indicator is included in the downlink control information.
The method of claim 6,

The ACK / NACK signal is characterized in that the cyclic repetition check bit is added only to the last received of the plurality of physical downlink shared channels, control channel transmission method.
In a terminal receiving a control channel,

Receive a mode indicator from a transmission point indicating that a physical downlink control channel is a one-to-many mode compatible with a plurality of physical downlink shared channels, mapped to the physical downlink control channel and the plurality of physical downlink shared channels Receiving downlink control information including common transmission parameters for the plurality of devices from the transmission point, receiving the plurality of physical downlink shared channels from the transmission point based on the transmission parameter, and transmitting the plurality of physical downlinks A terminal transceiver for transmitting an ACK / NACK signal on a common channel to the transmission point; And

And a terminal processor for determining the plurality of physical downlink shared channels based on the mode indicator and generating the ACK / NACK signal.
The method of claim 10, wherein the terminal transceiver unit,

And a bundling length indicator included in the downlink control information and indicating the number of the plurality of physical downlink shared channels from the transmission point.
The method of claim 10,

In the case where the mode indicator indicates that the physical downlink control channel is a mode capable of one-to-many correspondence with the plurality of physical downlink shared channels,

The terminal transceiver unit transmits the downlink control information further including a bundling flag indicating whether the physical downlink control channel currently corresponds to the plurality of physical downlink shared channels in a one-to-many manner. Terminal, characterized in that receiving from the point.
The method of claim 10, wherein the transceiver unit,

And the ACK / NACK signal generated based on a cyclic repetition check bit added to the last received one of the plurality of physical downlink shared channels as the transmission point.
In the transmission point for transmitting the control channel,

Transmitting a mode indicator to the terminal indicating that a physical downlink control channel is a mode capable of one-to-one correspondence with a plurality of physical downlink shared channels, mapped to the physical downlink control channel, and the plurality of physical downlink shared channels Downlink control information including a common transmission parameter for the terminal is transmitted to the terminal, the plurality of physical downlink shared channels are transmitted to the terminal based on the transmission parameter, and the plurality of physical downlink shared channels are transmitted to the terminal. A transmission point transceiver for receiving an ACK / NACK signal from the terminal; And

And a transmission point processor for generating the mode indicator and transmitting the generated mode indicator to the transmission point transceiver.
The method of claim 14,

In the case where the mode indicator indicates that the physical downlink control channel is a mode capable of one-to-many correspondence with the plurality of physical downlink shared channels,

The base station transceiver unit further includes the downlink control information including a bundling flag indicating whether the physical downlink control channel currently corresponds to the plurality of physical downlink shared channels in a one-to-many manner. Characterized in that the transmission point.