KR20150007391A - Apparatus and method for transmitting and receiving control channel in wireless communication system based on nct - Google Patents

Abstract

Provided are an apparatus and a method for transmitting a control channel, and an apparatus and a method for receiving the control channel in a wireless communications system based on a new carrier type (NCT). In the wireless communications system based on the NCT, a base station transmitting the control channel comprises: a cluster configuring unit clustering a pair of clustering physical resource blocks (PRB) to configure a cluster; and a transmission unit transmitting an enhanced physical downlink control channel (EPDCCH) to a terminal on the basis of the configured cluster.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a control channel transmission apparatus, a transmission method, a receiving apparatus, and a receiving method in a wireless communication system based on NCT,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication, and more particularly, to a wireless communication system based on a New Carrier Type (NCT), in which a control on a special subframe having a relatively small number of Orthogonal Frequency Division Multiplexing A channel transmitting apparatus, a transmitting method, a receiving apparatus, and a receiving method.

In a time division duplex (TDD) system, one frame may be composed of ten subframes each having a length of 1 millisecond, and each subframe includes a downlink subframe, , An uplink subframe, and a special subframe. Here, a subframe other than a special subframe is called a normal subframe by distinguishing it from a special subframe. For example, a normal subframe includes a downlink subframe and an uplink subframe in a TDD system, and includes a subframe in a Frequency Division Duplex (FDD) system. The special subframe includes a Downlink Pilot Time Slot (DwPTS), a Guard Period (GP), and an Uplink Pilot Time Slot (UpPTS) field.

Meanwhile, in the wireless communication system, an extended physical downlink control channel (EPDCCH: Extended-PDCCH) may be used for the purpose of extending the capacity of the PDCCH in addition to the physical downlink control channel (PDCCH) have. EPDCCH may also be referred to as an enhanced physical downlink control channel.

Like the PDCCH, the EPDCCH can be transmitted not only in a normal subframe but also in a special subframe. However, since there is a configuration in which the number of REs (Resource Elements) available for transmitting the EPDCCH is very small during the special subframe configuration, PDSCH and EPDCCH can not be transmitted in the special subframe configuration Only the PDCCH can be transmitted.

On the other hand, in a conventional multiple component carrier system using an element carrier (CC), the versatility of the physical layer is emphasized. Therefore, in the multi-element carrier system, there is still a problem such that control area redundancy and common signal overhead still exist, thereby reducing resources for the data signal and unnecessary loss in terms of spectral efficiency. Accordingly, new carrier types (NCTs) are being considered for efficient operation in next generation wireless communication systems.

In the NCT, a reference signal (RS) for downlink control channel or channel estimation is provided within a range where performance is not degraded or minimized compared with a legacy carrier type (LCT) Can be removed or reduced. This is to obtain maximum data transmission efficiency. An existing carrier wave is called a backward compatible carrier type (BCCT) by distinguishing it from this NCT.

The NCT may include a non-standalone NCT and a standalone NCT. A non-standalone NCT is an NCT that can not exist in a single cell form and can exist in the form of a secondary serving cell (SCell) when a primary serving cell (PCell) exists. On the other hand, a standalone NCT is an NCT that can exist in the form of a single cell (e.g., an order cell).

In this NCT, a CRS for demodulation other than a reference signal (TRS: Tracking RS or RCRS: Reduced CRS) used for synchronization may not be transmitted, and a physical downlink control channel (PDCCH) , A Physical HARQ Indicator CHannel (PHICH), and a Physical Control Format Indicator CHannel (PCFICH) may be removed or replaced with other types of channels.

Since the PDCCH may not be transmitted in the NCT, the EPDCCH can be transmitted in the special subframe by using the resource elements used for transmitting the PDCCH in the existing LCT.

However, there may be a case where resources for EPDCCH transmission are relatively small. For example, the special subframe configuration may have a relatively small number of resource elements for EPDCCH transmission as compared to the normal subframe. In this case, there are practically a lot of restrictions on transmitting the EPDCCH in the special subframe configuration. The same is true when the number of resource elements for EPDCCH transmission is small.

Therefore, there is a need for a method capable of effectively transmitting an EPDCCH even in a situation where the NCT has a relatively small number of resource elements.

SUMMARY OF THE INVENTION The present invention provides a control channel transmitting apparatus, a transmitting method, a receiving apparatus, and a receiving method in a wireless communication system based on NCT in a wireless communication system.

According to an aspect of the present invention, a base station for transmitting a control channel in a NCT (New Carrier Type) based wireless communication system includes a plurality of clusters of PRB (Physical Resource Block) And a transmitter for transmitting an Enhanced Physical Downlink Control Channel (EPDCCH) to the AT based on the configuration unit and the cluster.

In an exemplary embodiment, the cluster unit may map a resource element to an EREG (Enhanced Resource Element Group) for the EPDCCH on a cluster-by-cluster basis.

In another embodiment, the cluster unit may form the cluster by clustering a PRB pair constituting one EPDCCH set and at least one PRB pair adjacent to the PRB pair.

In another embodiment, the cluster unit may configure the cluster by clustering at least one pair of PRBs consecutively located on the frequency from a PRB pair constituting the EPDCCH set and a PRB pair constituting the EPDCCH set.

In another embodiment, the cluster unit sets a PRB pair indicating a start and a PRB pair indicating an end of a pair of PRBs constituting one EPDCCH set, respectively, and a pair of PRBs indicating the start and the end The PRB pairs located between PRB pairs can be clustered to form the cluster.

In another embodiment, the transmitter may transmit an RRC (Radio Resource Control) signal including information on the number of pairs of PRBs constituting the cluster to the terminal.

In another embodiment, the transmitter may transmit an RRC (Radio Resource Control) signal including information indicating a location of the cluster to the terminal.

According to another aspect of the present invention, in a method of transmitting a control channel by a base station in a NCT (New Carrier Type) based wireless communication system, a plurality of PRB (Physical Resource Block) pairs are clustered to form a cluster And transmitting the Enhanced Physical Downlink Control Channel (EPDCCH) to the AT based on the cluster.

According to another aspect of the present invention, a terminal receiving a control channel in a NCT (New Carrier Type) based wireless communication system includes a receiver for receiving an RRC (Radio Resource Control) signal and an EPDCCH The EPDCCH can be transmitted on the basis of a cluster formed by clustering a plurality of pairs of Physical Resource Block (PRB) pairs.

According to another aspect of the present invention, there is provided a method of receiving a control channel by a terminal in a NCT (New Carrier Type) based wireless communication system, the method comprising: receiving an RRC (Radio Resource Control) The EPDCCH may be transmitted based on a cluster configured by clustering a plurality of pairs of Physical Resource Blocks (PRBs).

It is possible to support more effective Extended Physical Downlink Control Channel (EPDCCH) transmission on the NCT (New Carrier Type).

1 is a block diagram illustrating a wireless communication system.
2 is a diagram showing RRC parameters for setting the number of PRB pairs defined in each EPDCCH set.
Figures 3A-3E illustrate examples of pairs of PRBs according to one embodiment.
4A is an exemplary diagram illustrating local transmission of an EPDCCH, and FIG. 4B is an exemplary diagram illustrating distributed transmission of an EPDCCH.
5 is a diagram showing an FDD frame structure.
6 is a diagram showing a TDD frame structure.
7 is a diagram illustrating a case where an EPDCCH is transmitted in a special subframe.
8A to 8D are diagrams showing the configuration of a cluster according to an example of the present invention.
9A to 9F are diagrams showing the configuration of a cluster according to another example of the present invention.
10A and 10B are diagrams showing the configuration of a cluster according to another example of the present invention.
11A and 11D are diagrams showing the configuration of a cluster according to another example of the present invention.
12A to 12D are diagrams illustrating EREG mapping according to an example of the present invention.
13 is a diagram showing an EREG mapping according to another example of the present invention.
14A and 14B are diagrams illustrating EREG mapping according to another example of the present invention.
15 is a diagram illustrating an EREG mapping according to another example of the present invention.
16 is a diagram illustrating an EREG mapping according to another example of the present invention.
17 is a flowchart illustrating a process in which an EPDCCH is transmitted and received between a terminal and a base station according to an exemplary embodiment of the present invention.
18 is a block diagram illustrating a terminal and a base station according to an example of the present invention.

Hereinafter, some embodiments 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 numerals even though they are shown in different drawings. In the following description of the embodiments 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 disclosure rather unclear.

The present invention will be described in the context of a communication network. A task in a communication network may be performed in a process of controlling a network and transmitting data in a system (e.g., a base station) that manages the communication network, Work can be done.

According to one embodiment of the present invention, 'transmitting a control channel' can be interpreted as meaning that control information is transmitted through a specific channel. Here, the control channel includes, for example, a physical downlink control channel (PDCCH), an extended PDCCH (EPDCCH), or a physical uplink control channel (PUCCH) .

1 is a block diagram illustrating a wireless communication system. This may be a network structure of an Evolved-Universal Mobile Telecommunications System (E-UMTS). The E-UMTS system may be called LTE (Long Term Evolution) or LTE-A (advanced) system. Wireless communication systems are widely deployed to provide various communication services such as voice transmission, packet data transmission, and the like.

On the other hand, there is no limitation on a multiple access technique applied to a wireless communication system. (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA , OFDM-CDMA, and the like can be used.

Here, TDD (Time Division Duplex) scheme in which uplink and downlink transmission are transmitted using different time periods or FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies may be used .

Referring to FIG. 1, a wireless communication system includes at least one base station (BS) 20 that provides a control plane and a user plane to a terminal.

A user equipment (UE) 10 may be fixed or mobile and may be a mobile station, an AMS (advanced MS), a user terminal (UT), a subscriber station (SS) It can be called a term.

The base station 20 generally refers to a point of communication with the terminal 10 and includes an evolved-NodeB (eNodeB), a base transceiver system (BTS), an access point, a femto-eNB, a pico-eNB, a home eNB, and a relay. The base station 20 may provide at least one cell to the terminal 10. [ The cell may mean a geographical area where the base station 20 provides communication services, or may refer to a specific frequency band. A cell may denote a downlink frequency resource and an uplink frequency resource. Or a cell may mean a combination of a downlink frequency resource and an optional uplink frequency resource. Also, in general, when one does not consider CA (Carrier Aggregation), uplink and downlink frequency resources always exist in one cell.

An interface for transmitting user traffic or control traffic may be used between the base stations 20. The source BS 21 refers to a base station in which a radio bearer is established with the current MS 10 and the target BS 22 has a function of terminating the radio bearer with the source BS 21 and newly Means a base station to perform a handover in order to set up a radio bearer.

The base stations 20 may be interconnected via an X2 interface. The X2 interface is used for exchanging messages between the base stations 20. Meanwhile, the base station 20 is connected to an Evolved Packet System (EPS), more specifically a Mobility Management Entity (MME) / Serving Gateway (S-GW) 30 via an S1 interface. S1 interface supports many-to-many-relations between the base station 20 and the MME / S-GW 30.

The PDN-GW 40 is used to provide packet data service to the MME / S-GW 30. [ The PDN-GW 40 is changed depending on the purpose of communication or the service, and the PDN-GW 40 supporting the specific service can be found using APN (Access Point Name) information.

A new carrier type (NCT: New Carrier Type) may be applied to such a wireless communication system. In the NCT, for example, signals such as PBCH (Physical Broadcast Channel), PDCCH (Physical Downlink Control Channel), PHICH (Physical HARQ Indicator CHannel) and PCFICH (Physical Control Format Indicator CHannel) may not be transmitted. Transmission modes (TM) 1 to 8 may not be supported in the NCT. That is, TM 9 or TM 10 can be supported in the NCT. In the NCT, a PDSCH transmission method having a maximum of 8 layers can be supported, and a DCT (Downlink Control Information) format 1A / 2D (or 2C) can be used for PDSCH (Physical Downlink Shared CHannel) transmission on the NCT. The DCI formats 1A / 2D (or 2C) may be indicated via the EPDCCH on the NCT and may be indicated through cross-carrier scheduling from the LCT (Legacy Carrier Type). DCI format 0/4 can also be used for EPDCCH transmission on the NCT. Since the TM 9 or TM 10 can be supported by the NCT, a CSI-RS (CSI-RS) for supporting channel state information (CSI) feedback can be supported on the NCT.

Specifically, an NCT may include a non-standalone NCT and a standalone NCT and an NCT having a dormant mode.

First, a non-standalone NCT can not exist in a single cell form and can exist in the form of a secondary serving cell (SCell) when a primary serving cell (PCell) exists . For example, a non-standalone NCT can be aggregated with an existing carrier type (LCT: Legacy Carrier Type) set to PCell by setting SCell to a terminal configured with CA (Carrier Aggregation).

Non-standalone NCTs can be classified into synchronized carrier types and unsynchronized carrier types. Synchronous NCT refers to an NCT operating with reference to the synchronization of other carriers (e.g., legacy carriers). In other words, the synchronous NCT may be an NCT that is synchronized in time and frequency with other carriers and does not require a separate synchronization procedure at the terminal. In the synchronous NCT, a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Common Reference Signal (CRS) may not be transmitted. This allows overhead reduction of CRS, PSS and SSS. In the synchronous NCT, there may be advantages such as interference mitigation, energy saving, and improved spectral efficiency for adjacent cells due to the reduction of the overhead, The network provider can more freely utilize the frequency bandwidth.

An asynchronous NCT is an NCT that can operate independently by acquiring independent synchronization independent of other carriers (e.g., legacy carriers). For the asynchronous NCT, the PSS and the SSS transmit the same as the legacy carrier type, but the CRS transmission frequency and transmission bandwidth may be small. For example, in an asynchronous NCT, a CRS may be transmitted with a certain period, in which case the CRS may be referred to as reduced CRS (reduced CRS) or may be referred to as a TRS (Tracking RS) since it can only be used for synchronization purposes. Specifically, for example, the TRS can be transmitted based on the CRS antenna port 0 with a 5 ms period on the time axis. The TRS can also be transmitted over the entire system bandwidth on the frequency axis, or only on some system bandwidths.

Second, the standalone NCT is an NCT that can exist in a single cell form. For example, a standalone NCT can exist in the form of a main serving cell. Standalone NCTs Like the non-standalone NCTs, the CRS can be removed, but the TRS mentioned above can be transmitted. Accordingly, the existing PDCCH, PHICH, and PCFICH, which are CRS-based control channels, can be removed or replaced with other types of channels. The demodulation of EPDCCH and PDSCH in the standalone NCT can be performed based on a demodulation reference signal (DMRS).

Hereinafter, a control channel for carrying common DL control information such as system information, paging information, and transmission power control information in a Common Search Space (CSS) based on the DMRS is referred to as a common EPDCCH, A control channel for carrying downlink control information in USS (UE Specific Search Space) is referred to as a UE-specific EPDCCH. The simple EPDCCH includes both the common EPDCCH and the UE-specific EPDCCH.

2 is a diagram showing RRC parameters for setting the number of PRB pairs defined in each EPDCCH set. Hereinafter, an EPDCCH set for EPDCCH transmission will be described with reference to FIG.

One EPDCCH set p is defined as a group including N PRBs (Physical Resource Block) pairs, for example, 1 = K = 2, . The EPDCCH set may also be referred to as the EPDCCH PRB set. Here, one PRB pair may be defined as a resource region corresponding to one RB (Resource Block) on the frequency axis and two slots on the time axis. Or one PRB pair may mean an area corresponding to 12 resource elements (RE) having a bandwidth of, for example, 180 KHz and a 15KHz subcarrier spacing in a normal subframe.

As shown in FIG. 2, the RRC (Radio Resource Control) setting for each EPDCCH set includes information on the transmission type (distributed transmission or local transmission) of the EPDCCH and the number N of PRB pairs used for the EPDCCH set And the like. The EPDCCH set may be composed of two, four or eight PRB pairs each, and each EPDCCH set need not have the same N value to each other. The PRB pairs may be overlapped, partially overlapped, or may not overlap at all between different EPDCCH sets. The PRB pair in each EPDCCH set may be indicated by resourceBlockAssignment-r11 and numberPRBPairs-r11 among the parameters shown in FIG.

Figures 3A-3E illustrate examples of pairs of PRBs according to one embodiment.

Referring to FIGS. 3A to 3E, sixteen Enhanced Resource Element Groups (EREGs) are included in one PRB pair. That is, all EREGs belonging to one PRB pair can be represented by indices 0 to 15.

In FIGS. 3A to 3E, 0, 1, 2,..., And 15 denoted in each resource element represent an index of an EREG to which each resource element belongs (or is mapped). Within the pair of PRBs, indexes 0, 1, 2, ..., 15 of the EREG for each resource element can be indexed in ascending order from the first subcarrier on the first OFDM symbol along the frequency axis on the time axis. When EREG indexing is completed for the first OFDM symbol within a pair of PRBs, EREG indexing for each resource element can be performed sequentially from the first subcarrier along the frequency axis in the next time axis OFDM symbol. Meanwhile, the resource element indicated by R in Figs. 3A to 3E is a resource element used for transmission of the DMRS. Resource elements used for transmission of DMRS can be excluded from EREG indexing.

The arrangement and the number of DMRSs in the PRB pair may be different from each other in each of the embodiments as shown in FIG. 3A to FIG. 3E. For example, in FIG. 3A, since 24 resource elements are used for the DMRS, 16 EREGs are generated from 144 resource elements excluding 24 resource elements. In this case, one EREG may contain nine resource elements. However, in addition to the DMRS, a CSI-RS or CRS may be placed in one PRB pair. In this case, the number of resource elements included in the EREG can be reduced because the number of available resource elements (available REs) in the PRB pair is reduced due to CSI-RS or CRS. In addition, since the number of resource elements available varies depending on the CP type, the number of resource elements included in the EREG can also be changed. Also, since the number of available resource elements varies depending on the type of the subframe, the number of resource elements included in the EREG can also be changed.

For example, FIG. 3A shows that sixteen EREGs are formed from the remaining 144 resource elements excluding the 24 DMRS resource elements out of 168 total resource elements in the PRB pair composed of the normal sub-frame and the normal CP.

In another example, FIG. 3B shows that sixteen EREGs are formed from the remaining 128 resource elements excluding the sixteen DMRS resource elements out of the total 144 resource elements in the PRB pair composed of the normal subframe and the extended CP. In this case, 0 EREG contains 8 resource elements.

In another example, FIG. 3C shows a PRB pair composed of special subframes 1 (9 OFDM symbols), 2 (10 OFDM symbols), 6 (9 OFDM symbols) In the configurations 1 and 6 (Embodiment A), 16 EREGs are formed from the remaining 84 resource elements excluding the 24 resource elements for the DM-RS among 108 resource elements available in the downlink, and special subframe configurations 2 and 7 (Embodiment B) shows that sixteen EREGs are formed from the remaining 96 resource elements excluding the 24 resource elements for the DM-RS among the 120 available resource elements in the downlink.

In another example, FIG. 3D shows a case where in a PRB pair composed of special subframe configurations 3 (11 OFDM symbols), 4 (12 OFDM symbols), 8 (11 OFDM symbols) In the configurations 3 and 8 (Embodiment A), 16 EREGs are formed from the remaining 108 resource elements excluding the 24 resource elements for the DM-RS among 132 resource elements available in the downlink, and a special subframe configuration 4 In the example B), 16 EREGs are formed from the remaining 120 resource elements excluding the 24 resource elements for the DM-RS among the 144 available resource elements in the downlink, and in the special subframe structure 9 (not shown) Indicates that 16 EREGs are formed from 60 resource elements except for 12 DM-RS resource elements out of 72 available resource elements.

As another example, FIG. 3E shows a configuration of a special subframe consisting of 8 OFDM symbols, 2 OFDM symbols, 3 OFDM symbols, 5 OFDM symbols, 6 OFDM symbols, In the PRB pair, sixteen EREGs are formed from the remaining 88 resource elements excluding the eight resource elements for the DM-RS among the 96 available resource elements in the downlink in the special subframe configurations 1 and 5 (Embodiment A) And 16 EREGs are formed from the remaining 100 resource elements excluding the 8 resource elements for the DM-RS among the 108 resource elements available in the downlink in the special subframe configurations 2 and 6 (Embodiment B) And in the special subframe structure 3 (not shown), 16 EREGs are formed from the remaining 112 resource elements excluding the DM-RS resource elements out of 120 available resource elements in the downlink.

Thus, although the number of resource elements included in the EREG may depend on the type of the reference signal, the CP type, and the subframe type, the number 16 of EREG included in one PRB pair may be fixed.

In the special subframe configuration of FIGS. 3C to 3E, the resource elements indicated by oblique lines to the right of the slot 1 correspond to a Guard Period (GP) and an Uplink Pilot Time Slot (UpPTS). The number of Orthogonal Frequency Division Multiplexing (OFDM) symbols for the Downlink Pilot Time Slot (DwPTS) varies depending on the particular subframe configuration and the associated CP type.

The EPDCCH is transmitted based on one or more Enhanced Control Channel Elements (ECCE). An ECCE is a basic unit through which EPDCCH is transmitted. For example, one EPDCCH can be mapped to one ECCE, two ECCEs, four ECCEs, or eight ECCEs. Therefore, the EPDCCH for transmitting downlink control information (DCI) is transmitted in a manner of aggregating one ECCE or a plurality of ECCEs.

An ECCE may include a plurality of EREGs. For example, an ECCE may include four EREGs or eight EREGs. Here, one EREG is a group composed of at least one resource element.

How many EREGs are included in the ECCE may depend on the type of subframe (e.g., normal subframe or special subframe), and CP type. For example, an ECCE may include four EREGs in a normal CP (cyclic prefix) and a normal or special subframe configuration 3, 4, 8, an extended CP, a normal CP, and a special And 8 EREGs in subframe configurations 1, 2, 6, 7, and 9. That is, one ECCE may include one or more EREGs. For example, the number of EREGs included in each ECCE can be defined as shown in Table 1 below.

Normal CP Expanded CP The normal subframe Special subframe configurations 3,4,8 Special subframe configuration 1,2,6,7,9 The normal subframe Special subframe structure 1,2,3,5,6 4 8

Referring to Table 1, N ^ECCE _{EREG, which} is the number of EREGs constituting one ECCE, is defined according to the type and CP type of each subframe. For example, in a PRB pair consisting of a normal CP and a normal subframe or a normal CP and a special subframe configuration 3, 4, and 8, N ^ECCE _EREG is 4, and an extended CP and a normal subframe or a normal CP and a special subframe configuration 1 , 2, 6, 7, 9, or 8, where N ^ECCE _EREG is 8 in the PRB pair consisting of extended CPs and special subframe configurations 1, On the other hand, the number of _ECCEs per one PRB pair N ^RB _ECCE ^E can be determined through N ^ECCE _EREG . Where N ^RB _ECCE = 16 / N ^ECCE _EREG . N ^{ECCE When} _EREG = 4, the number of _ECCEs included in one PRB pair is N ^RB _ECCE = _16/4 = 4. When N ^ECCE _EREG = 8, the number of _ECCEs included in one PRB pair is N ^RB _ECCE = _16/8 = 2. On the other hand, the number of ECCEs constituting one EPDCCH N ^EPDCCH _ECCE can be defined as shown in Table 2 according to the format of EPDCCH as an example.

EPDCCH format Number of ECCEs constituting one EPDCCH N ^EPDCCH _ECCE Casea Case B Local transmission Distributed transmission Local transmission Distributed transmission 0 2 2 One One One 4 4 2 2 2 8 8 4 4 3 16 16 8 8 4 - 32 - 16

The index (i.e., position) of the EREGs belonging to the ECCE can be defined by a certain rule, which can be referred to as an ECCE-to-EREG mapping. There are two types of ECCE-to-EREG mapping: localized transmission and distributed transmission. 4A is an exemplary diagram illustrating local transmission of an EPDCCH, and FIG. 4B is an exemplary diagram illustrating distributed transmission of an EPDCCH. An EREG group constituting one ECCE in the local transmission is selected in the EREG in one PRB pair.

For example, suppose that one ECCE includes four EREGs, and one EPDCCH set is configured to include four PRB pairs.

EREG 1, EREG 5, EREG 9, and EREG 13 in the PRB pair # 0, as shown in FIG. 4A. , ECCE # 2 = {EREG 2, EREG 6, EREG 10, EREG 14}, ECCE # 3 = {EREG 3, EREG 7, EREG 11, EREG 15}. This also applies to PRB pairs # 1, # 2 and # 3. Or one ECCE is configured to include eight EREGs, ECCE # 0 = {EREG 0, EREG 2, EREG 4, EREG 6, EREG 8, EREG 10, EREG 12, EREG 14} EREG 1, EREG 3, EREG 5, EREG 7, EREG 9, EREG 11, EREG 13, EREG 15}.

On the other hand, according to the distributed transmission, as shown in FIG. 4B, an EREG group constituting one ECCE is selected from EREGs of different PRB pairs. For example, ECCE # 0 = EREG 0 of {PRB pair # 0, EREG 4 of PRB pair # 1, EREG 8 of PRB pair # 2, EREG 12 of PRB pair # 3). This applies equally to other ECCEs.

EPDCCH based on local transmission may be referred to as local EPDCCH, and EPDCCH based on distributed transmission may be referred to as distributed EPDCCH. The distributed EPDCCH can obtain a diversity gain, and the local EPDCCH can be used for control information transmission through preferred precoding for a specific terminal with frequency selective characteristics.

The base station can transmit a plurality of EPDCCHs in one subframe. The terminal monitors at least one common EPDCCH in a common search space (CSS) for each subframe, or searches for a terminal specific search space (USS) At least one UE-specific EPDCCH may be monitored. Here, monitoring means that the UE attempts to decode the EPDCCH according to the EPDCCH format. Monitoring may also be referred to as blind decoding.

The blind decoding demasking a cyclic redundancy check (CRC) of the received EPDCCH (referred to as an EPDCCH candidate) by an identifier related to the common control information, checks the CRC error, Is a control channel. The reason for performing blind decoding is that the UE does not know in advance where the EPDCCH is transmitted in the common search space or in the UE-specific search space and in which aggregation unit or DCI format.

A search space (SS) can be used. The search space is a monitoring set of the ECCE for EPDCCH. The search space is divided into a common search space and a terminal-specific search space. The terminal monitors the EPDCCH within the search space. The common search space is a space for searching an EPDCCH having common downlink control information such as system information, paging information, random access grant, MCCH change notification, transmission power control information, and the like. The UE-specific search space is a space for searching an EPDCCH having dedicated downlink control information for each UE.

The starting point of the search space may be defined differently from the common search space and the terminal specific search space. For example, although the starting point of the common search space is fixed regardless of the sub-frame, the starting point of the UE-specific search space may be a terminal identifier (for example, a Cell-Radio Network Temporary Identifier (C-RNTI) Or a slot number in a radio frame. When the starting point of the UE-specific search space is within the common search space, the UE-specific search space and the common search space may overlap.

In order for the UE to monitor the EPDCCH in the common search space and / or the UE-specific search space, the amount of the ECCE constituting the common search space or the UE-specific search space, the aggregation level of the ECCE, The number of EPDCCH candidates according to a predetermined rule or a combination thereof must be defined according to a certain rule. The definition of these rules is called an EPDCCH assignment rule (EPDCCH assignment rule). The EPDCCH allocation rule is a communication protocol in which the BS and the MS promise to each other. That is, a procedure for the base station to transmit the EPDCCH to the UE, the number of monitoring times of the UE, and the like are determined according to the EPDCCH allocation rule.

The EPDCCH allocation rule can be classified into, for example, Case 1 to Case 3. This is because the number of resource elements constituting one ECCE existing in one PRB pair may vary depending on various settings (for example, RS overhead, legacy control region, etc.) Therefore, from the viewpoint of link adaptation, the link performance experienced by one EPDCCH needs to be uniform regardless of other settings.

이거나, 또는 ii) 노멀 CP 및 특별 서브프레임 설정 3,4,8 이고 DCI 2/2A/2B/2C/2D가 모니터링되며 모니터링되는 셀의 하향링크 전체 PRB 쌍의 수가

이거나, 또는 iii) 노멀 CP 및 노멀 서브프레임이고 DCI 1A/1B/1D/1/2/2A/2B/2C/2D/0/4 모니터링되며 n_EPDCCH<104인 경우, 또는 iv) 노멀 CP 및 특별 서브프레임 설정 3,4,8이고 DCI 1A/1B/1D/1/2/2A/2B/2C/2D/0/4가 모니터링되며 n_EPDCCH<104인 경우를 포함한다. 이 경우 하나의 PRB 쌍 내에서 4개의 ECCE가 구성될 수 있다.Case 1 includes i) a normal CP and a normal subframe, where DCI 2 / 2A / 2B / 2C / 2D is monitored and the number of downlink total PRB pairs

Or ii) DCI 2 / 2A / 2B / 2C / 2D is monitored with the normal CP and special subframe settings 3, 4, 8 and the number of downlink total PRB pairs of the monitored cells

Or iii) is a normal CP and a normal subframe and monitored by DCI 1A / 1B / 1D / 1/2 / 2A / 2B / 2C / 2D / _0/4 and n _EPDCCH <104; or iv) Subframe settings 3, 4, 8 and DCI 1A / 1B / 1D / 1/2 / 2A / 2B / 2C / 2D / _0/4 are monitored and n _EPDCCH <104. In this case, four ECCEs can be constructed within one PRB pair.

  In Case 2, i) extended CP and normal subframe and DCI 1A / 1B / 1D / 1/2 / 2B / 2C / 2D / 0/4 are monitored, or ii) 2, 6, 7, 9 and DCI 1A / 1B / 1D / 1/2 / 2B / 2C / 2D / 0/4 are monitored, or iii) , 6, and DCI 1A / 1B / 1D / 1/2 / 2B / 2C / 2D / 0/4 are monitored. Case 3 can be applied to cases other than Case 1 and Case 2.

FIG. 5 is a diagram showing an FDD frame structure, and FIG. 6 is a diagram showing a TDD frame structure.

Referring to FIG. 5, in the FDD, the terminal-specific EPDCCH is not transmitted to the central 6PRB pair in which the PBCH and the PSS / SSS are transmitted. The PBCH is transmitted on the first four OFDM symbols in the second slot of the FDD / TDD subframe # 0. In the FDD, PSS and SSS are transmitted on the last two OFDM symbols in the first slot in subframe # 0 and subframe # 5. In FIG. 5, the CRS indicates that the CRS is transmitted on the entire band, and actually does not indicate that all subcarriers in one OFDM symbol are used as a CRS.

6, SSS is transmitted on the last OFDM symbol of subframe # 0 and subframe # 5, and PSS is transmitted on the third OFDM symbol of subframe # 1 and subframe # 6, unlike FDD in TDD. do.

In TDD, each subframe may be composed of a downlink subframe, an uplink subframe, and a special subframe. A subframe other than a special subframe is called a normal subframe by distinguishing it from a special subframe. For example, a normal subframe includes a downlink subframe in TDD, an uplink subframe, and a subframe in the FDD.

The special subframe includes three fields: DwPTS, GP, and UpPTS. Depending on the length of each field, the TDD configuration of a particular subframe may be defined to a maximum of nine according to the CP type, have.

TDD configuration of special subframe Normal CP Extended CP DwPTS UpPTS DwPTS UpPTS In the uplink, the normal CP In the uplink, the extended CP In the uplink, the normal CP In the uplink, the extended CP 0 6592Ts 2192Ts 2560Ts 7680Ts 2192Ts 2560Ts One 19760Ts 20480Ts 2 21952Ts 23040Ts 3 24144Ts 25600Ts 4 26336Ts 7680Ts 4384Ts 5120Ts 5 6592Ts 4384Ts 5120Ts 20480Ts 6 19760Ts 23040Ts 7 21952Ts 12800Ts 8 24144Ts - - - 9 13168Ts - - -

Referring to Table 3, the TDD configuration of the special subframe may be different depending on whether the CP type is a normal CP or an extended CP. Here, Ts is a unit time indicating the size of the field on the time axis of the frame, and may be, for example, Ts = 1 / (15000 * 2048) sec.

On the other hand, the uplink-downlink configuration in TDD is shown in Table 4 below.

Uplink-downlink configuration Uplink - Downlink
Cycle of turning point Sub-frame number 0 One 2 3 4 5 6 7 8 9 0 5ms D S U U U D S U U U One 5ms D S U U D D S U U D 2 5ms D S U D D D S U D D 3 10ms D S U U U D D D D D 4 10ms D S U U D D D D D D 5 10ms D S U D D D D D D D 6 5ms D S U U U D S U U D

In Table 4, D denotes a downlink subframe, U denotes an uplink subframe, and S denotes a special subframe.

7 is a diagram illustrating a case where an EPDCCH is transmitted in a special subframe.

If the EPDCCH is transmitted in one example (normal CP + special subframe configurations # 0 and # 5) and (extended CP + special subframe configurations # 0, # 4 and # 7), a resource element for EPDCCH transmission Mapping is possible. FIG. 7 shows possible resource element mapping for EPDCCH transmission in the normal CP and special subframe configurations # 0 and # 5 as an example. However, as shown in FIG. 7, in the special subframe structure, since the number of resource elements available for one ECCE or EREG in one PRB pair is very small, PDSCH and / or EPDCCH are transmitted Or only the PDCCH may be transmittable.

Also, in the case of subframe numbers # 1 and # 6 in TDD, a resource element is required for PSS transmission within a central 6 PRB pair. Therefore, the number of resource elements available for EPDCCH transmission per one PRB pair according to the special subframe configuration and CP type is as shown in Table 5 below.

CP type Normal CP Expanded CP Subframe type Sp 0 Sp 5 Sp 0 Sp 4 Sp 7 DwPTS length (symbol) 3 3 3 3 5 Number of Support Elements Available if PSS is Included
DMRS (AP7-10 with time moving using symbol # 0, 1) 12 12 16 16 40 Number of Support Elements Available if PSS is Included
DMRS (AP7-8 with time moving using symbol # 0, 1) 18 18 16 16 40 Number of Support Elements Available Without PSS
DMRS (AP 7-10 with time moving using symbol # 0, 1) 24 24 28 28 52 Number of Support Elements Available if PSS is Included
DMRS (AP 7-8 with time moving using symbol # 0, 1) 30 30 28 28 52

In Table 5, Sp x denotes a special subframe configuration, and AP denotes an antenna port. The number of resource elements for the DMRS is assumed to be 12 in the case of using AP 7-10 in one PRB pair and 6 (normal CP) or 8 (extended CP) in case of using only AP 7-8. Of course, the number of resource elements for different numbers of DMRSs can be assumed through other assumptions.

Since the number of resource elements available for EPDCCH transmission in the corresponding subframe configuration is very small, it is necessary to force a very high aggregation unit to maintain the EPDCCH link performance. This means that the number of UEs (i.e., EPDCCH capacity) that the BS can schedule can be reduced. Therefore, a method for reducing the influence of the capacity of resources available for EPDCCH transmission is required.

FIGS. 8A to 8D are diagrams showing the configuration of a cluster according to an example of the present invention, FIGS. 9A to 9F are views showing the configuration of a cluster according to another example of the present invention, FIG. 8 is a diagram showing the configuration of a cluster according to another example. FIG. 11A and 11D are diagrams showing the configuration of a cluster according to another example of the present invention.

The base station according to the present invention may form a cluster by clustering a plurality of PRB pairs to support more efficient EPDCCH transmission on the NCT. Then, the EPDCCH can be transmitted to the UE based on the configured cluster. To this end, the base station according to the present invention may map resource elements to EREGs for EPDCCH on a cluster basis. This can have the same meaning as the numbering of resource elements constituting one EREG in a cluster unit and the numbering of an EREG constituting one ECCE in a cluster unit. The numbering does not limit local transmission and distributed transmission.

First Embodiment

As a first embodiment, a base station according to the present invention may be configured such that at least one second PRB pair adjacent on the frequency from a first PRB pair constituting one EPDCCH set, as shown in Figs. 8A to 8E, And the like. For example, when there are PRB pairs A and B constituting an EPDCCH set, cluster 1 including PRB pair A and cluster 2 including PRB pair B can be respectively configured. At this time, the number X (for example, 2, 4, or 8) of PRB pairs constituting one cluster can be RRC signaled through the EPDCCH set-up. Specifically, the base station includes an X value in an EPDCCH set configuration including information (for example, resourceBlockAssignment-r11) for a pair of PRBs constituting one EPDCCH set as shown in FIG. 2 to generate PRB Information about the pair can be transmitted to the terminal.

For example, when the number N of PRB pairs constituting one EPDCCH set is 2 and the number X of PRB pairs constituting one cluster is 2, P0 (PRB pair # 0, for example) and P0 The cluster # 0 = {P0, P1}, the cluster # 1 = {P10, P11} may be indicated as the value of X = 2 is additionally signaled according to the present invention have. 1, ..., P10 + (X-1)}, when the value of X is an arbitrary value, the cluster # 0 = {P0, P0 + -1)}. Through such a method, a combination as shown in Table 6 below can be made. However, the combination of clusters in this embodiment is not limited to the following values.

Combination N X Number of PRB pairs required Number of clusters 0 2 2 4 2 One 2 4 8 2 2 2 8 16 2 3 4 2 8 4 4 4 4 16 4 5 4 8 32 4 6 8 2 16 8 7 8 4 32 8 8 8 8 64 8

Referring to Table 6, the number of clusters is equal to the number N of PRB pairs constituting one EPDCCH. That is, clusters can be constructed by the number of PRB pairs constituting the EPDCCH.

At this time, the base station can prevent the settings for the PRB pairs constituting the N clusters from overlapping each other.

8A shows a case in which the number N of PRB pairs constituting one EPDCCH set is 4 and the number X of PRB pairs constituting one cluster is 2, for example.

8B shows a case where the number N of PRB pairs constituting one EPDCCH set is 2 and the number X of PRB pairs constituting one cluster is 4, for example.

8C shows a case where the number N of PRB pairs constituting one EPDCCH set is 4 and the number X of PRB pairs constituting one cluster is 4, for example.

FIG. 8D shows a case where the number N of PRB pairs constituting one EPDCCH set is 2, and the number X of PRB pairs constituting one cluster is 8.

Second Embodiment

As a second embodiment, a base station according to the present invention may be configured such that a plurality of PRB pairs constituting one EPDCCH set are configured such that each PRB pair is the start or end of a unique cluster. The base station can construct a cluster by clustering consecutive PRB pairs located between a PRB pair indicating the start of a specific cluster on the frequency and a PRB pair indicating an end of the specific cluster. The start and end of the cluster may be implicitly indicated by signaling (e.g., resourceBlockAssignment-r11) indicating the PRB pair belonging to the EPDCCH set.

For example, when a plurality of PRB pairs N constituting one EPDCCH set are four (P0, P1, P2, P3), P0 (for example, PRB pair # # 3), P2 (for example, PRB pair # 8), and P3 (for example, PRB pair # 11) are indicated by conventional signaling. The terminal recognizes P0 and P1 as the start and end of cluster # 0, respectively, and recognizes P2 and P3 as the start and end of cluster # 1, respectively. The terminal can be interpreted as cluster # 0 = {P0, P0 + 1, ..., P1}, cluster # 1 = {P2, P2 + 1, ..., P3}. Through such a method, a combination as shown in Table 7 below can be made. However, the combination of clusters in this embodiment is not limited to the following values.

Combination N Number of PRB pairs per cluster Number of clusters 0 2 Determined by pairs of PRBs indicating start and end, depending on the configuration One One 2 Determined by pairs of PRBs indicating start and end, depending on the configuration One 2 4 Determined by pairs of PRBs indicating start and end, depending on the configuration 2 3 4 Determined by pairs of PRBs indicating start and end, depending on the configuration 2 4 8 Determined by pairs of PRBs indicating start and end, depending on the configuration 4 5 8 Determined by pairs of PRBs indicating start and end, depending on the configuration 4

In Table 7, the number of clusters is equal to 1/2 of the number N of PRB pairs constituting one EPDCCH set. At this time, the base station can prevent the settings for the PRB pairs constituting N / 2 clusters from overlapping each other.

9A and 9C show a case in which the number N of PRB pairs constituting one EPDCCH set is 8. In FIGS. 9B and 9D, the number N of PRB pairs constituting one EPDCCH set is 4 Fig. In the case of FIG. 9A, it is shown that one cluster is composed of only two PRB pairs as the PRB pairs indicating start and end for one cluster are consecutively located on the frequency, and in the case of FIG. 9C, It is shown that one cluster consists of four PRB pairs as there are two PRB pairs in frequency between the PRB pair indicating the end. Similarly, in the case of FIG. 9B, it is shown that one cluster is composed of four PRB pairs as there are two PRB pairs in frequency between PRB pairs indicating start and end for one cluster, and one cluster There are six pairs of PRBs in the frequency band between the pair of PRBs indicating the start and the end of the PRB pair, so that one cluster is composed of eight pairs of PRBs.

9E and 9F illustrate a case where the number N of PRB pairs constituting one EPDCCH set is two.

In the case of FIG. 9E, it is shown that one cluster is composed of 8 PRB pairs as there are 6 PRB pairs on the frequency between PRB pairs indicating start and end for one cluster, and FIG. And two pairs of PRBs are present on the frequency band between the pair of PRBs indicating the end, one cluster is composed of four pairs of PRBs.

Third Embodiment

As in the third embodiment, the base station according to the present invention clusters at least one PRB pair adjacent on the frequency from a pair of PRBs constituting one EPDCCH set to a pair of PRBs constituting the EPDCCH set, as in the first embodiment, And can perform EPDCCH transmission using the configured cluster. However, in this case, unlike the first embodiment, a predetermined value between the BS and the MS can be used as an X value, which is the number of PRB pairs constituting one cluster. In this case, no additional RRC signaling between the base station and the terminal is required. In the second embodiment, the cluster can be configured as shown in Figs. 8A to 8D according to a predetermined value between the base station and the terminal, as in the first embodiment.

Fourth Embodiment

As a fourth embodiment, the base station according to the present invention can add information for indicating a cluster within the EPDCCH set-up and transmit it to the terminal. Here, the number X of pairs of PRBs constituting one cluster may be included in the EPDCCH set-up or may be predetermined between the BS and the MS. The numbering of the clusters can be performed according to the number of PRB pairs sequentially determined from a low frequency on the entire bandwidth, such as the numbering of existing PRB pairs.

For example, the number of clusters may be indicated by including numberCluster- {n2, n4, n8} within the EPDCCH set-up and the location of the cluster may be indicated by including clusterAssignment in the EPDCCH set-up. That is, the unit constituting the EPDCCH set is a cluster, not a PRB pair. The location of the cluster may be determined via RRC signaling comprising the EPDCCH set-up and r in Equation (1).

는

,

및

는 하나의 클러스터를 구성하는 PRB 쌍의 수,

는 하나의 EPDCCH 셋을 구성하는 클러스터의 수, p는 EPDCCH 셋 인덱스를 각각 나타낸다. 한편,

은 고유 라벨

로부터 확장된 이항 계수(extended binomial coefficient)이다.here,

The

,

And

The number of PRB pairs constituting one cluster,

Denotes the number of clusters constituting one EPDCCH set, and p denotes an EPDCCH set index. Meanwhile,

Is a unique label

Is an extended binomial coefficient.

10A shows a case where two clusters constitute one EPDCCH set and four PRB pairs constitute one cluster. In FIG. 10B, two clusters constitute one EPDCCH set, and two clusters constitute one EPDCCH set. PRB pairs constitute one cluster.

Fifth Embodiment

Fifth Embodiment The numbering for the EREG can also be performed on a cluster-by-cluster basis. However, in this case, the base station can signal that the PRB pairs constituting one cluster may be scattered without being mapped to successive PRB pairs.

For this purpose, the base station RRC signals the number N (e.g., 2, 4, or 8) of the PRB pairs constituting one cluster through the EPDCCH set-up, while signaling for the existing PRB pair in the EPDCCH set- (E.g., resourceBlockAssignment-r11) can be signaled in conjunction with the cluster ID. That is, it is possible to indicate explicitly which PRB pair each cluster includes by associating a cluster ID (IDentifier) with each signaling for an existing PRB pair. At this time, the number of clusters can also be signaled. As an example, the resourceBlockAssignment value in the EPDCCH set-up may be indicated for each cluster as follows. resourceBlockAssignment-r11 BIT STRING (SIZE (4..38)) for cluster # 0, ..., resourceBlockAssignment-r11 BIT STRING (SIZE

E.g. When the number N of PRB pairs constituting one cluster is 2 and the number of cluster IDs is 2 (# 0, # 1), the corresponding PRB pair can be configured according to the N value set for each cluster. In this case, since cluster ID # 0 is N = 2, P0 (for example, PRB pair # 0) and P1 (for example, PRB pair # 10) are indicated by existing signaling and cluster ID # 1 is N = 2 Based on P2 and P3. Therefore, cluster # 0 can be composed of {P0, P1} and cluster # 1 can be composed of {P2, P3}. Through such a method, a combination as shown in the following Table 8 or Table 9 can be made. However, the combination of clusters in this embodiment is not limited to the following values. Only some of them may be used.

Combination N Number of clusters Number of PRB pairs required 0 2 2 4 One 2 4 8 2 4 2 8 3 4 4 16 4 8 2 16 5 8 4 32

Combination N Number of clusters Number of PRB pairs required 0 2 2 4 One 2 4 8 2 2 8 16 3 4 2 8 4 4 4 16 5 4 8 32 6 8 2 16 7 8 4 32 8 8 8 64

In Tables 8 and 9, the number of clusters may be indicated separately or may be predetermined between the base station and the terminal. Depending on the number of clusters, the cluster ID may also be indicated.

11A shows a case where the number N of PRB pairs constituting one cluster is 2 and the number of clusters constituting one EPDCCH set is 2, and in FIG. 11B, the number of PRB pairs constituting one cluster The number N is 4 and the number of clusters constituting one EPDCCH set is two. 11C shows a case where the number N of PRB pairs constituting one cluster is 4 and the number of clusters constituting one EPDCCH is 4, and in FIG. 11D, the number N of pairs of PRB constituting one cluster Is 8 and the number of clusters constituting one EPDCCH is 2 is shown. As described above, according to the present embodiment, pairs of PRBs constituting one cluster can be mapped continuously or mapped on a frequency basis using a cluster ID.

In the above description, a method of forming a cluster and a method of signaling a cluster configuration have been described. When EPDCCH is transmitted on a cluster, the basic unit of transmission is ECCE and the ECCE is composed of EREG. However, as the concept of cluster is introduced, EREG needs to be newly defined at the cluster level. Hereinafter, a method of mapping each EREG to a cluster will be described.

FIGS. 12A to 12D are diagrams illustrating EREG mapping according to an exemplary embodiment of the present invention. FIG. 13 is a diagram illustrating an EREG mapping according to another example of the present invention. FIGS. 14A, 14B, 15, Fig. 8 is a diagram showing an EREG mapping according to another example. Fig.

The base station according to the present invention can number 0 to 15 EREGs for EPDCCH transmission on a cluster basis in a special subframe. EREG numbering excludes resource elements for DMRS (AP 7-10 in normal CP or AP 7-8 in extended CP). The resource element numbered by the index i is the resource element constituting the EREG index i. The resource element is included in the EREG allocated for the EPDCCH transmission. However, the resource element is not included in the PBCH or the PRB pair used for the synchronization signal transmission. Also, the resource element is not used for transmission of a UE-specific reference signal or a CSI reference signal. The number of resource elements that satisfy these conditions per cluster may be determined according to the sub-frame configuration and CP type as shown in Table 10 below.

CP type Normal CP Expanded CP Subframe Type Sp 0 Sp 5 Sp 0 Sp 4 Sp 7 DwPTS length (symbol) 3 3 3 3 5 Number of Support Elements Available if PSS is Included
DMRS (AP7-10 with time moving using symbol # 0, 1) 12 * X 12 * X 16 * X 16 * X 40 * X Number of Support Elements Available if PSS is Included
DMRS (AP7-8 with time moving using symbol # 0, 1) 18 * X 18 * X 16 * X 16 * X 40 * X Number of Support Elements Available Without PSS
DMRS (AP 7-10 with time moving using symbol # 0, 1) 24 * X 24 * X 28 * X 28 * X 52 * X Number of Support Elements Available if PSS is Included
DMRS (AP 7-8 with time moving using symbol # 0, 1) 30 * X 30 * X 28 * X 28 * X 52 * X

In Table 10, Sp numbers (e.g., SP0) represent special subframe configurations, AP represents an antenna port, and X represents the number of PRB pairs included in one cluster. The number of resource elements in Table 10 is determined by the resource elements for the DMRS and the PSS. There may be additional overheads (e.g., ZP / NZP, CSI-RS, CRS, or TRS).

For example, FIG. 12A shows a case where no PSS exists in the normal CP and the special subframe configuration # 0, the number of resource elements for the DMRS is 24, and one cluster is composed of two PRB pairs. And 16 EREGs are formed from the remaining 48 resource elements except for 24 resource elements.

In another example, FIG. 12B shows a case where PSS exists in the normal CP and special subframe configuration # 0, the number of resource elements for DMRS is 24, and one cluster is composed of two PRB pairs. 16 EREGs are formed from 36 resource elements excluding 24 resource elements and 12 resource elements for PSS.

12C shows a case where PSS does not exist in the normal CP and special subframe configuration # 0 and 12 resource elements for DMRS and one cluster is composed of two PRB pairs. In the case of DMRS And 16 EREGs are formed from 60 resource elements except for 12 resource elements.

In another example, FIG. 12D shows a case where PSS exists in the normal CP and special subframe configuration # 0, 12 resource elements for DMRS, and one cluster is composed of two PRB pairs. 16 EREGs are formed from the remaining 48 resource elements except for 12 resource elements for PSS and 12 resource elements for PSS.

13 shows a case where no PSS exists in the normal CP and the special subframe configuration # 0, and 48 resource elements for the DMRS and one cluster is composed of four PRB pairs. In the case of the DMRS 16 EREGs are formed from the remaining 96 resource elements except for 48 resource elements. Although the numbering for EREG is omitted in Fig. 13, it can be performed in the same manner as in Figs. 12A to 12D.

14A shows a case where PSS does not exist in the extended CP and the special subframe configuration # 0, and 16 resource elements for the DMRS and one cluster is composed of two PRB pairs. In the case of DMRS And 16 EREGs are formed from the remaining 56 resource elements except for 16 resource elements.

In another example, FIG. 14B shows a case where PSS exists in the extended CP and special subframe configuration # 0, 16 resource elements for DMRS and one cluster is composed of two PRB pairs. 16 EREGs are formed from 44 resource elements except for 16 resource elements for PSS and 12 resource elements for PSS.

In another example, FIG. 15 shows a case where PSS does not exist in the extended CP and special subframe configuration # 7, and 16 resource elements for DMRS and one cluster is composed of two PRB pairs. In case of DMRS And 16 EREGs are formed from the remaining 104 resource elements except for 16 resource elements for EREG.

On the other hand, FIG. 16 shows the EREG numbering when PRB pairs constituting one cluster may be scattered without being mapped to successive PRB pairs. In this case as well, the PRB pairs constituting one cluster can be numbered in cluster units as in the case of successive mapping.

17 is a flowchart illustrating a process in which an EPDCCH is transmitted and received between a terminal and a base station according to an exemplary embodiment of the present invention.

Referring to FIG. 17, the BS configures a cluster by clustering a plurality of PRB pairs (1710). For example, the base station may form a cluster for EPDCCH transmission by clustering PRB pairs constituting one EPDCCH set and at least one PRB pair adjacent to the PRB pair. Specifically, the base station can form a cluster by clustering at least one PRB pair continuously located on the frequency from the PRB pair constituting the EPDCCH set and the PRB pair constituting the EPDCCH set.

On the other hand, as another example, the base station sets a PRB pair indicating the start of the cluster and a PRB pair indicating the end of the cluster among the PRB pairs constituting one EPDCCH set, and sets PRB pair indicating the start and PRB pair indicating the end May be clustered to form a cluster. Here, the base station may map the resource element to the EREG on a cluster-by-cluster basis.

On the other hand, as another example, the base station may select a pair of PRBs included in each cluster to constitute a cluster.

Meanwhile, the BS may perform RRC signaling with the MS (1720). In this case, the BS may transmit an RRC message including an RRC message including information on the number of PRB pairs constituting the cluster and / or information indicating the location of the cluster to the MS. For example, an example of the RRC message may be defined as shown in the following table.

EPDCCH-SetConfig-r11 :: = SEQUENCE { epdcch-SetIdentity-r11 EPDCCH-SetIdentity-r11, epdcch-TransmissionType-r11 ENUMERATED {localized, distributed} numberPRBPairs-r11 ENUMERATED {n2, n4, n8} resourceBlockAssignment-r11 BITSTRING (SIZE (4..38)), dmrs-ScramblingSequenceInt-r11 INTEGER (0..503), pucch-ResourceStatOffset INTEGER (0..2047), re-MappingQCLConfigList-Id INTEGER (1..4) numberPRBPairsOfCluster INTEGER (1 ... 2)

Referring to Table 11, numberPRBPairsOfCluster is information about the number X of pairs of PRBs constituting the cluster, and may have a value of 1-4, which is only an example.

Or another example of the RRC message may be defined as shown in the following table.

EPDCCH-SetConfig-r11 :: = SEQUENCE { epdcch-SetIdentity-r11 EPDCCH-SetIdentity-r11, epdcch-TransmissionType-r11 ENUMERATED {localized, distributed} numberPRBPairs-r11 ENUMERATED {n2, n4, n8} resourceBlockAssignment-r11 BITSTRING (SIZE (4..38)), dmrs-ScramblingSequenceInt-r11 INTEGER (0..503), pucch-ResourceStatOffset INTEGER (0..2047), re-MappingQCLConfigList-Id INTEGER (1..4) numberOfCluster ENUMERATED {n2, n4, n8} clusterAssignment BITSTRING (SIZE (4..38)),

Referring to Table 12, numberOfCluster may be one of 2, 4, or 8 as the number of clusters, and this is only an example. Also, the clusterAssignment is information indicating the position of the cluster and may have a length of 4 to 38 bits, but this is only an example.

Alternatively, for example, another example of the RRC message may be defined as shown in the following table.

EPDCCH-SetConfig-r11 :: = SEQUENCE { epdcch-SetIdentity-r11 EPDCCH-SetIdentity-r11, epdcch-TransmissionType-r11 ENUMERATED {localized, distributed} numberPRBPairs-r11 ENUMERATED {n2, n4, n8} resourceBlockAssignment-r11 BITSTRING (SIZE (4..38)), dmrs-ScramblingSequenceInt-r11 INTEGER (0..503), pucch-ResourceStatOffset INTEGER (0..2047), re-MappingQCLConfigList-Id INTEGER (1..4) resourceBlockAssignment-r11 BIT STRING (SIZE (4..38)) for cluster # 0 resourceBlockAssignment-r11 BIT STRING (SIZE (4..38)) for cluster # N-1

Upon receiving the RRC message from the base station, the MS can recognize the resource element for the EPDCCH by analyzing the received RRC message (1730).

Thereafter, when the base station transmits the EPDCCH to the UE based on the cluster (1740), the UE can receive the EPDCCH based on the resource element for the EPDCCH recognized (1750).

18 is a block diagram illustrating a base station and a terminal according to an example of the present invention.

Referring to FIG. 18, a base station 1700 includes a base station processor 1710, a transmitter 1720, and a receiver 1730. The base station processor 1710 may include a cluster configuration unit 1711 and a data processing unit 1712.

The cluster configuration unit 1711 forms a cluster by clustering a plurality of PRB pairs. Then, resource elements can be mapped to EREGs for EPDCCH on a cluster-by-cluster basis.

For example, the cluster configuration unit 1711 may form a cluster by clustering a PRB pair constituting one EPDCCH set and at least one PRB pair adjacent to the PRB pair. Specifically, the cluster forming unit 17110 can form a cluster by clustering at least one PRB pair continuously located on the frequency from a PRB pair constituting the EPDCCH set and a PRB pair constituting the EPDCCH set. On the other hand, the cluster configuration unit 1711 sets PRB pair indicating the start and PRB pair indicating the end among the PRB pairs constituting one EPDCCH set, respectively, and is located between the PRB pair indicating the start and the PRB pair indicating the end PRB pairs may be clustered to form a cluster.

The data processing unit 1712 generates a DCI to be sent to the terminal 1800, and adds a CRC for error detection to the DCI. The data processing unit 2872 can generate the encoded data by performing channel coding on the control information to which the CRC is added.

The transmitter 1720 transmits an RRC message to the terminal 1800. Then, the EPDCCH is transmitted to the terminal 1800 based on the cluster constituted by the cluster configuration unit 1710. At this time, the RRC message may include information indicating the number of pairs of PRBs constituting the cluster and / or information indicating the position of the cluster.

The receiving unit 1730 can receive the serial link data from the terminal 1800.

The terminal 1800 includes a receiving unit 1810, a terminal processor 1820, and a transmitting unit 1830. The terminal processor 1820 may include a monitoring control unit 1821 and a data processing unit 1822.

The reception unit 1810 receives the RRC message from the base station 1700 and receives the EPDCCH, and monitors the EPDCCH received under the control of the monitoring control unit 1821. The EPDCCH can be transmitted on the basis of a cluster constituted by clustering a plurality of PRB pairs. For example, the cluster may be constituted by clustering a PRB pair constituting one EPDCCH set and at least one PRB pair adjacent to the PRB pair, or a PRB pair representing the beginning of the pair of PRB constituting one EPDCCH set and an end PRB pairs are respectively set and PRB pairs located between the PRB pair indicating the start and the PRB pair indicating the end are clustered. EREGs for EPDCCH can be mapped on a cluster-by-cluster basis.

Meanwhile, the process of monitoring the EPDCCH by the receiver 1810 includes demapping the resource element to the modulation symbol for the EPDCCH based on a predetermined EPDCCH allocation rule, a demodulation process for extracting the modulation symbol from the encoded data, A process of decoding DCI added to the DCI, a process of demasking the CRC added to the DCI, and an error detection process of detecting an error. Also, the receiver 1810 can monitor the EPDCCH based on a predetermined EPDCCH allocation rule between the terminal 1800 and the base station 1700.

The monitoring control unit 1821 controls the receiving unit 1810 to monitor the EPDCCH candidate according to each aggregation unit and transmits the DCI obtained as a result of decoding the EPDCCH in the receiving unit 1810 to the data processing unit 1822. [

The data processor 1822 analyzes the RRC message received from the receiver 1810 and recognizes the resource element for the EPDCCH. Then, it analyzes the DCI received from the monitoring control unit 1821 and controls the terminal 1800 to perform the control operation indicated by the DCI. At this time, the RRC message may include at least one of information on the number of PRB pairs constituting the cluster and information indicating the position of the cluster.

The transmission unit 1830 transmits the uplink data generated by the data processing unit 1822 to the base station 1700.

All of the functions described above may be performed by a processor such as a microprocessor, a controller, a microcontroller, an application specific integrated circuit (ASIC), etc. according to software or program code or the like coded to perform the function. The design, development and implementation of the above code will be apparent to those skilled in the art based on the description of the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention. You will understand. Therefore, it is intended that the present invention covers all embodiments falling within the scope of the following claims, rather than being limited to the above-described embodiments.

Claims (24)

1. A base station for transmitting a control channel in an NCT (New Carrier Type) based wireless communication system,
CLAIMS 1. A cluster system comprising: a cluster constituent unit for forming a cluster by clustering a plurality of PRB (Physical Resource Block) pairs; And
And a transmission unit for transmitting an Enhanced Physical Downlink Control Channel (EPDCCH)
/ RTI &gt; The method according to claim 1,
Wherein the cluster constituent part comprises:
And mapping the resource element to an Enhanced Resource Element Group (EREG) for the EPDCCH on a cluster-by-cluster basis. The method according to claim 1,
Wherein the cluster constituent part comprises:
Wherein the cluster is formed by clustering a pair of PRBs constituting one EPDCCH set and at least one pair of PRBs adjacent to the pair of PRBs. The method of claim 3,
Wherein the cluster constituent part comprises:
Wherein the cluster is formed by clustering at least one PRB pair continuously located on a frequency from a pair of PRBs constituting the EPDCCH set and a pair of PRBs constituting the EPDCCH set. The method according to claim 1,
Wherein the cluster constituent part comprises:
A pair of PRBs indicating the start and a pair of PRBs indicating the start and a pair of PRBs constituting one EPDCCH set are respectively set and the PRB pairs located between the PRB pair indicating the start and the ending PRB pair are clustered To form the cluster. The method according to claim 1,
Wherein the transmission unit comprises:
And transmits a Radio Resource Control (RRC) signal including information on the number of PRB pairs constituting the cluster to the MS. The method according to claim 1,
Wherein the transmission unit comprises:
And transmits a Radio Resource Control (RRC) signal including information indicating a location of the cluster to the terminal. A method for transmitting a control channel by a base station in an NCT (New Carrier Type) based wireless communication system,
Configuring a cluster by clustering a plurality of pairs of PRBs; And
Transmitting an Enhanced Physical Downlink Control Channel (EPDCCH) to the MS based on the cluster configured as described above
/ RTI &gt; 9. The method of claim 8,
After the constructing step,
And mapping the resource element to an EREG (Enhanced Resource Element Group) for the EPDCCH on a cluster-by-cluster basis. 9. The method of claim 8,
Wherein the configuring comprises:
Wherein the step of constructing the cluster comprises clustering a pair of PRBs constituting one EPDCCH set and at least one pair of PRBs adjacent to the pair of PRBs. 11. The method of claim 10,
Wherein the configuring comprises:
Wherein the cluster is formed by clustering at least one PRB pair continuously located on a frequency from a pair of PRBs constituting the EPDCCH set and a pair of PRBs constituting the EPDCCH set. 9. The method of claim 8,
Wherein the configuring comprises:
Setting a PRB pair indicating a start and a PRB pair indicating an end among PRB pairs constituting one EPDCCH set respectively; And
Clustering PRB pairs located between the PRB pair indicating the start and the PRB pair indicating the end to construct the cluster
And transmitting the control channel to the control channel. 9. The method of claim 8,
After the constructing step,
(RRC) signal including information on the number of pairs of PRBs constituting the cluster to the MS. 9. The method of claim 8,
After the constructing step,
Further comprising the step of transmitting a radio resource control (RRC) signal including information indicating a position of the cluster to the mobile station. A terminal for receiving a control channel in a new carrier type (NCT) based wireless communication system,
A receiver for receiving an RRC (Radio Resource Control) signal; And
A data processor for analyzing the received RRC message and recognizing a resource element for an Enhanced Physical Downlink Control Channel (EPDCCH)
Lt; / RTI &gt;
The EPDCCH includes:
Wherein a plurality of PRB (Physical Resource Block) pairs are transmitted based on clusters formed by clustering. 16. The method of claim 15,
In the EREG (Enhanced Resource Element Group) for the EPDCCH,
Wherein resource elements are mapped on a cluster-by-cluster basis. 16. The method of claim 15,
The cluster includes:
Wherein the PRB pair constituting one EPDCCH set and at least one PRB pair adjacent to the PRB pair are clustered. 18. The method of claim 17,
The cluster includes:
Wherein at least one pair of PRBs continuously located in the frequency domain is clustered from a pair of PRBs constituting the EPDCCH set and a pair of PRBs constituting the EPDCCH set. 16. The method of claim 15,
The cluster includes:
A PRB pair indicating the start and a PRB pair indicating the beginning are set respectively and a PRB pair positioned between the PRB pair indicating the start and the PRB pair indicating the end are set in a cluster . 16. The method of claim 15,
The RRC message includes:
Information on the number of pairs of PRBs constituting the cluster, and information indicating a position of the cluster. A method for receiving a control channel by a terminal in an NCT (New Carrier Type) based wireless communication system,
Receiving an RRC (Radio Resource Control) signal; And
Recognizing a resource element for an Enhanced Physical Downlink Control Channel (EPDCCH) by analyzing the received RRC message
Lt; / RTI &gt;
The EPDCCH includes:
Wherein a plurality of PRB (Physical Resource Block) pairs are transmitted based on clusters formed by clustering. 22. The method of claim 21,
In the EREG (Enhanced Resource Element Group) for the EPDCCH,
And resource elements are mapped on a cluster-by-cluster basis. 22. The method of claim 21,
The cluster includes:
A pair of PRBs constituting one EPDCCH set and at least one pair of PRBs adjacent to the pair of PRBs are clustered, or a PRB pair representing the start and a PRB pair representing the end among the PRB pairs constituting the one EPDCCH set And the PRB pairs located between the PRB pair indicating the start and the PRB pair indicating the end are clustered. 22. The method of claim 21,
The RRC message includes:
Information on the number of PRB pairs constituting the cluster, and information indicating a position of the cluster.

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