KR20140047532A - Control channel transmission method of base station and control channel receiving method of user equipment, apparatus - Google Patents

Abstract

The present invention relates to a control channel transmission method for increasing the capacity of a multi-user control channel in a wireless multi-antenna system. The control channel transmission method according to an embodiment of the present invention includes: a step of excluding resource elements regarding a demodulation reference signal (DM-RS) from each physical resource block pair of each sub-frame in a frequency-first-time-after order and sequentially maps enhanced resource element group (EREG) indexes on resource elements, forming an ECCE by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs, and allocating a down-link control channel located in a data area comprising at least an ECCE; and a step of transmitting the down-link control channel located in the data area to a base station.

Description

Control channel transmission method of base station and control channel reception method of terminal, apparatus thereof {Control Channel Transmission Method of Base Station and Control Channel Receiving Method of User Equipment, Apparatus}

The present invention relates to a control channel transmission method and apparatus for increasing the capacity of a multi-user control channel in a wireless multi-antenna system.

As communications systems evolved, consumers, such as businesses and individuals, used a wide variety of wireless terminals. In a mobile communication system such as the current 3GPP family Long Term Evolution (LTE) and LTE-A (LTE Advanced), a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data, , It is required to develop a technology capable of transmitting large-capacity data based on a wired communication network. As a method for transmitting a large amount of data, a method of efficiently transmitting data through a plurality of element carriers can be used.

In this system, the time-frequency resource is divided into a region for transmitting a control channel (for example, a physical downlink control channel (PDCCH)) and a region for transmitting a data channel (for example, a Physical Downlink Shared CHannel (PDSCH) .

In order to improve the performance of a wireless communication system, technologies such as Multiple-Input Multiple-Output (MIMO) and Coordinated Multi-Point Transmission / Reception (CoMP) have been considered. More control information may be required to use this technique. However, the limited control region may be insufficient to include all control channels.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus and method for efficiently transmitting control information to a mobile station in a wireless communication system.

The present invention provides a method and apparatus for allocating a control channel when a control channel is extended in a data region in a wireless communication system.

In one aspect, the present invention provides an EREG (Enhanced Resource) to resource elements sequentially except for resource elements for DM-RS (Demodulation Reference Signal) in frequency order after frequency priority in each physical resource block pair for each subframe. Element index), and form one ECCE by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs, and located in a data region composed of at least one ECCE. Allocating a downlink control channel; And transmitting a downlink control channel located in the data area to the base station.

In another aspect, the present invention provides an EREG (Enhanced Resource) to resource elements sequentially except for resource elements for DM-RS (Demodulation Reference Signal) in frequency order after frequency priority in each physical resource block pair for each subframe. Element index), and form one ECCE by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs, and located in a data region composed of at least one ECCE. Receiving a downlink control channel; And obtaining control information from a downlink control channel located in the data area.

In another aspect, the present invention provides an EREG (Enhanced) to resource elements sequentially except for resource elements for DM-RS (Demodulation Reference Signal) in frequency order after frequency priority in each physical resource block pair for each subframe. Resource indices (Index of Resource Element Group), and form one ECCE by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs, and are located in a data region composed of at least one ECCE. A resource allocator for allocating a downlink control channel; And a transmitter for transmitting a downlink control channel located in the data area to a base station.

In another aspect, the present invention provides an EREG (Enhanced) to resource elements sequentially except for resource elements for DM-RS (Demodulation Reference Signal) in frequency order after frequency priority in each physical resource block pair for each subframe. Resource indices (Index of Resource Element Group), and form one ECCE by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs, and are located in a data region composed of at least one ECCE. A receiver for receiving a downlink control channel; And a control information extracting unit for obtaining control information from a downlink control channel located in the data region.

According to the present invention, in a wireless communication system, a base station can efficiently transmit control information to a mobile station.

1 shows a communication system to which embodiments of the present invention are applied.
FIG. 2 shows a control region in which a control channel including a PDCCH, a PCFICH, and a PHICH are transmitted in one subframe, and a data region in which a data channel including a PDSCH is transmitted.
3 is an ePDCCH implementation scheme to which one embodiment of the present disclosure is applied.
4 shows the distributed transmission and the centralized transmission of the ePDCCH.
FIG. 5 shows the positions of PSS / SSS on a symbol of OFDM in the case of FDD and TDD.
FIG. 6 shows the positions of PBCHs on OFDM symbols.
FIG. 7 shows positions of subcarriers (resource elements) of PSS / SSS, PBCH for the entire bands of 20 MHz, 10 MHz, 5 MHz, 3 MHz and 1.4 MHz, respectively.
FIG. 8 illustrates a symbol-based cyclic shifted eREG index for a PRB pair when CRS port 0 is set.
FIG. 9 shows the structure of subframes of one radio frame in the case of FDD and TDD.
FIG. 10 shows the structure of uplink and downlink subframes according to TDD settings in case of TDD.
11 shows modulation methods in downlink transmission.
FIG. 12 shows a method of modulating PDSCH and ePDCCH in the data area (PDSCH area).
13 is a conceptual diagram of a search space of an ePDCCH USS and CSS mapped to a data area (PDSCH area).
14 is a block diagram showing the configuration of a base station according to another embodiment.
15 is a block diagram showing the configuration of a base station according to another embodiment.
16 is a flowchart showing a control channel transmission / reception method according to still another embodiment.

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

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

1 shows a communication system to which embodiments of the present invention are applied.

Communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

1, a communication system includes a user equipment (UE) 10 and a transmission point 20 for performing uplink and downlink communication with the terminal 10. [

The terminal 10 or user equipment (UE) in the present specification is a comprehensive concept of a user terminal in wireless communication. The terminal 10 or UE is a mobile terminal in the GSM, a mobile station (MS) in UT, User Terminal, SS (Subscriber Station), wireless device, and the like.

A transmission terminal 20 or a cell generally refers to a station that communicates with the terminal 10 and includes a base station, a Node-B, an evolved Node-B (eNB), a base transceiver station (BTS) System, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and the like.

In this specification, a transmission terminal 20 or a cell should be interpreted in a generic sense to indicate a partial area covered by a BSC (Base Station Controller) in a CDMA, a NodeB of a WCDMA, etc., and a RRH Which means any type of device capable of communicating with one terminal, such as a cell, a cell, a head, a relay node, a sector of a macro cell, a site, a microcell such as another femtocell, Used as a concept.

Herein, the terminal 10 and the transmission terminal 20 are used in a broad sense as a transmitting / receiving entity used to implement the technical or technical idea described in the present specification and are not limited to a specific term or word.

Although one terminal 10 and one transmission terminal 20 are shown in Fig. 1, the present invention is not limited thereto. One transmission terminal 20 can communicate with a plurality of terminals 10 and one terminal 10 can communicate with a plurality of transmission terminals 20. [

There is no limitation on a multiple access technique applied to a communication system, and the present invention is applicable to a CDMA (Code Division Multiple Access), a TDMA (Time Division Multiple Access), an FDMA (Frequency Division Multiple Access), an OFDMA (Orthogonal Frequency Division Multiple Access) -FDMA, OFDM-TDMA, and OFDM-CDMA.

In addition, the present invention can be applied to a TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, a Frequency Division Duplex (FDD) scheme in which different frequencies are used, It is applicable to the hybrid duplexing method.

Specifically, the embodiment of the present invention is applied to asynchronous wireless communication that evolves into LTE (Long Term Evolution) and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA- . It should be understood that the present invention is not limited to or limited to a particular wireless communication field and should be construed as including all technical fields to which the spirit of the present invention may be applied.

Referring to FIG. 1, a terminal 10 and a transmission terminal 20 can perform uplink and downlink communications.

The transmission terminal 20 performs downlink transmission to the terminal 10. The transmission unit 20 may transmit a Physical Downlink Shared Channel (PDSCH), which is a primary physical channel for unicast transmission. In addition, the transmission terminal 20 transmits scheduling approval information for transmission on the uplink data channel (for example, a physical uplink shared channel (PUSCH)), downlink control information such as scheduling required for PDSCH reception, A Physical Downlink Control Channel (PDCCH) for transmitting information, a Physical Control Format Indicator Channel (PCFICH) for transmitting an indicator for distinguishing between PDSCH and PDCCH regions, an uplink transmission And a physical HARQ indicator channel (PHICH) for transmission of HARQ (Hybrid Automatic Repeat reQuest) acknowledgment to the BS. Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

The transmission terminal 20 transmits a cell-specific reference signal (CRS), a MBSFN reference signal (MBSFN-RS), a UE-specific reference signal (DM-RS), a position reference signal (PRS), and a CSI reference signal (CSI-RS).

On the other hand, one radioframe or radio frame is composed of 10 subframes, and one subframe is composed of two slots. The radio frame has a length of 10 ms and the subframe has a length of 1.0 ms. In general, a basic unit of data transmission is a subframe unit, and downlink or uplink scheduling is performed in units of subframes.

One slot may have a plurality of OFDM symbols in the time domain and at least one subcarrier in the frequency domain. For example, the slot may include 7 OFDM symbols in the time domain (in case of Normal Cyclic Prefix) or 6 (in case of Extended Cyclic Prefix) and 12 subcarriers in the frequency domain. The time-frequency domain defined by one slot may be referred to as a resource block (RB), but is not limited thereto.

2 shows a control region 201 in which a control channel including a PDCCH, a PCFICH, and a PHICH are transmitted in one subframe, and a data region 202 in which a data channel including a PDSCH is transmitted. In Fig. 2, the horizontal axis represents time and the vertical axis represents frequency. FIG. 2 shows one sub-frame (1 ms) on the time axis and one channel (for example 1.4, 3, 5, 10, 15, or 20 MHz) on the frequency axis.

The PCFICH consists of 2 bits of information corresponding to the OFDM symbol, which is the size of the control area 201, and is encoded into a 32-bit code word. The encoded bits are scrambled using cell-specific and sub-frame-specific scrambling codes to randomize intercell interference and then modulated with Quadrature Phase Shift Keying (QPSK) to form 16 resource elements Lt; / RTI > The PCFICH is always mapped to the first OFDM symbol of each subframe. When the PCFICH is mapped to the first ODFM symbol of the subframe, it is divided into four groups, and the groups are well separated and mapped in the frequency domain to obtain excellent diversity as a whole.

The PDCCH (control information) is used to transmit downlink control information (DCI) such as scheduling decisions and power control commands. As an example, in LTE / LTE-A, DCI format 0 and DCI format 4 are used for uplink grant. The DCI format 1 / 1A / 1B / 1C / 1D / 2 / 2A / 2B / 2C is used for downlink scheduling assignment. And DCI format 3 / 3A is used for power control.

Each DCI message payload is accompanied by a cyclic redundancy check (CRC), and an RNTI (Radio Network Temporary Identifier) for identifying the UE is included in the CRC calculation process. After appending the CRC, the bits are encoded into a tail-biting convolutional code, and are matched to the amount of resources used for PDCCH transmission through rate matching.

The PDCCH may be transmitted in a common search space or a UE specific search space of the control domain 201. [ Each terminal 10 searches for a PDCCH through blind decoding in a common search space commonly allocated to UEs in a cell and in a UE-specific search space assigned to itself, and upon confirming PDCCH reception, It is possible to perform control based on the control information transmitted through the network.

Meanwhile, the LTE / LTE-A system defines the use of a plurality of unit carriers (Component Carriers) as a scheme for expanding the bandwidth to satisfy the system requirements, that is, a high data rate. In this case, one CC can have a maximum bandwidth of 20 MHz, and resources can be allocated within 20 MHz according to the corresponding service. However, this is only one example according to the process of implementing the system. .

In order to increase the data transmission speed, technologies such as a Multiple Input / Multiple Output (MIMO), a Coordinated Multiple Point (CoMP), and a relay node have been proposed. It is necessary to transmit more control information in the same transmission terminal as the base station.

However, when the size of the control region in which the PDCCH is transmitted is limited, a method of increasing the transmission capacity of the PDCCH can be considered as a method of transmitting control information to be transmitted through the PDCCH in the data area in which the PDSCH is transmitted. This method can support a large PDCCH capacity without reducing the reception reliability of the PDCCH. Control information corresponding to a PDCCH transmitted in a data region, for example, a PDSCH region, may be referred to as extended control information (Extended PDCCH, ePDCCH, X-PDCCH) or PDCCH-A (PDCCH-Advanced) Hereinafter, ePDCCH will be collectively described. The ePDCCH is also used for the R-PDCCH, which is the control channel for the relay. That is, the ePDCCH is a concept including both a control channel for relay and a control channel for inter-cell interference control. According to an embodiment of the present invention, the ePDCCH can be allocated to a data area (data channel area) of an arbitrary subframe.

The above-described ePDCCH is a new type of PDCCH considered in the Rel-11 LTE system, and it is necessary to allocate uplink control information (i.e., PUCCH) that can be caused by introducing the new PDCCH.

3 is an ePDCCH implementation scheme to which one embodiment of the present disclosure is applied.

The legacy PDCCH for the existing Rel-8/9/10 UE is transmitted in the legacy PDCCH region and the e-DCCCH region is transmitted from the Rel-11 UE through the upper layer signaling or system information (SI) A mode in which blind decoding is performed only for the E-PDCCH region may be considered.

According to the present embodiments, a new type carrier (NTC), Coordinated Multipoint Transmission / Reception (CoMP), and a downlink MIMO (Multi-input) are used in Carrier Aggregation (CA) in 3GPP LTE / EPDCCH for multi-output can be allocated to a PDSCH (Physical Downlink Shared Channel) which is a data area.

In this specification, allocation of control information is used in the same sense as allocation of a control channel. In other words, the allocation of control channels in this specification means allocating control information to resource elements.

At this time, the control channel is allocated in units of PRB (Physical Resource Block) pairs corresponding to two slots, i.e., one subframe, and PDSCH and ePDCCH can not be simultaneously allocated to one PRB pair. In other words, PDSCH and ePDCCH can not be multiplexed in one PRB pair.

Meanwhile, control information or control channels of two or more UEs may be allocated to two or more PRB pairs or may be allocated in one PRB pair to multiplex control information of UEs.

4 shows the distributed transmission and the centralized transmission of the ePDCCH.

Referring to FIG. 4, when multiplexing the control information of the UEs, one eCCE may be allocated to two or more PRB pairs in a distributed manner or localized in one PRB pair. The former case is referred to as a distributed transmission or distributed type (FIG. 4A), and the latter case is referred to as a centralized transmission or centralized type (FIG. 4B).

Localized transmission improves performance in low-speed movement. Distributed transmission increases control information in the control area during high-speed movement. Performance is improved over the transmitted PDCCH.

Meanwhile, it may support a common search space (CSS) in connection with a search space. RNTI, P-RNTI, RA-RNTI, TPC-PUCCH-RNTI, and TPC-PUSCH-RNTI, which can transmit a common RNTI (Common RNTI).

The ePDCCH set (ePDCCH set) may be defined as a group of N PRB pairs (N is a natural number greater than 0 and less than the number of PRBs of the entire bandwidth). For example, N may be 1 or 2 ⁿ (n = 1, 2, 3, 4, 5) in a centralized transmission, but is not limited thereto. The centralized ePDCCH may also be transmitted in the ePDCCH set.

N may be 2, 4, 8, 16 in distributed transmission, but is not limited thereto. In other words, the distributed ePDCCH can be transmitted using N PRB pairs of the ePDCCH set.

The set of K (K > = 1) ePDCCHs may be configured to be UE-specific. In this case, the maximum value for K may be any one of 2, 3, 4, and 6, but is not limited thereto. The K ePDCCH sets may not all have the same N PRB pairs. At this time, the total number of blind decoding of ePDCCH may be independent of K value or independent. The total number of blind decoding of the ePDCCH for the UE may be spread over the configured K ePDCCH sets. In other words, since the total number of ePDCCH USS blind decoding per component carrier is 32 or 48 according to the configuration of the uplink MIMO, the total number of blind decoding of the ePDCCH for the UE can be distributed to the configured K ePDCCH sets have.

Each ePDCCH set may be configured for a centralized ePDCCH or a distributed ePDCCH. That is, each ePDCCH set can not be composed of a mixture of a centralized ePDCCH or a distributed ePDCCH. For example, a set of K ePDCCHs may consist of KL sets for a centralized ePDCCH and KD sets for a distributed ePDCCH. At this time, KL and KD may be zero.

Meanwhile, K ePDCCH sets may be allocated for one UE. Since each ePDCCH set is a distributed type or a centralized type, KL centralized type ePDCCHs and KD distributed type ePDCCHs are allocated for one UE . That is, KL + KD = K can be obtained.

PRB pairs of ePDCCH sets with different logical ePDCCH set indices may overlap, partially overlap, or not overlap as a whole.

FIG. 5 shows the positions of PSS / SSS on a symbol of OFDM in the case of FDD and TDD.

Referring to FIG. 5, in the case of FDD, the PSS is transmitted to the last symbol of the first slot of the subframes 0 and 5, and the SSS is transmitted to the second symbol at the end of the same slot.

In the case of TDD, the PSS is transmitted in the third symbol of subframes 1 and 6 (ie, DwPTS), and the SSS is transmitted in the last symbol of subframes 0 and 5.

6 shows the locations of PBCH on a symbol of OFDM.

Referring to FIG. 6, the PBCH is mapped to four subframes. The PBCH is mapped to the first four symbols of the second slot of subframe 0 of each radio frame.

FIG. 7 shows the positions of subcarriers (resource elements) of PSS / SSS and PBCH for the entire band of 20 MHz, 10 MHz, 5 MHz, 3 MHz, and 1.4 MHz, respectively.

Referring to FIGS. 5 and 7, in the case of FDD, the PSS is matched to 72 subcarriers in the center of the entire band. Therefore, the PSS occupies 72 resource elements in the center except DC subcarriers in subframes 0 and 5. The SSS occupies 72 Resource Elements in the middle except the DC subcarriers in subframes 0 and 5.

In the case of TDD, the PSS occupies 72 resource elements in the center except DC subcarriers in subframes 1 and 6. In the same way as FDD, in the case of TDD, the SSS occupies 72 resource elements in the center excluding DC subcarriers in subframes 0 and 5.

Referring to FIGS. 6 and 7, the PBCH is transmitted over 72 subcarriers in the center of the entire band in the first four symbols of the second slot of subframe 0.

At this time, the ePDCCH is not transmitted to the PRB pairs including the PSS / SSS or the PBCH. In other words, in the case of FDD, the PSS occupies 72 resource elements in the center except for the DC subcarriers in the 0 and 5 subframes, and the SSS occupies 72 resource elements in the center except for the DC subcarriers in the subframes 0 and 5 The ePDCCH is not transmitted to the PRB pairs including 72 resource elements in the middle excluding the DC subcarriers in the subframes 0 and 5.

In the case of TDD, the PSS occupies 72 resource elements in the middle except for the DC subcarriers in the subframes 1 and 6, and the SSS occupies 72 resource elements in the middle except the DC subcarriers in the subframes 0 and 5 The ePDCCH is not transmitted to the PRB pairs including 72 resource elements in the middle excluding the DC subcarriers in the subframes including the PSS and the SSS.

Meanwhile, since the PBCH is transmitted over 72 subcarriers in the center of the entire band in the first 4 symbols of the second slot of the subframe 0, the ePDCCH includes 72 resource elements in the center of the entire band in the subframe 0 Lt; RTI ID = 0.0 > PRB < / RTI >

On the other hand, the transmitting end does not transmit the ePDCCH in the special subframe configuration 0 or 5 in the normal CP, the special subframe in the special subframe configuration 0, 4 and 7 in the extended CP, and the receiving end receives the ePDCCH in the special subframe described above Do not expect.

The mapping of the eREG to the RE may be fixed depending on the frame structure type, the sub frame configuration and the CP length, or may be the same regardless of these.

Special subframes with the same DM-RS positions can also map REGs to REs. The mapping of eREG to RE does not depend on the presence of other signals such as the number of PRB pairs, the number of subframes, the size of the control region, the DwPS length, CRS, CSI-RS, PRS.

At this time, the indexes of the eREGs can be sequentially mapped to the REs except for the REs for the DM-RS in frequency order after the frequency priority in each PRB pair.

The total number of ePDCCH USS blind decoding per component carrier may be 32 or 48 depending on the configuration of the uplink MIMO, but is not limited thereto.

And may support a cyclic shift of the indexes of the eREGs allocated in each OFDM symbol. It may also support additional relocation in OFDM symbols carrying DM-RSs.

FIG. 8 illustrates a symbol-based cyclic shifted eREG index for a PRB pair when CRS port 0 is set.

Even if another CRS port is set, a symbol-based cyclic shifted eREG indexing for a PRB pair may be performed as shown in FIG. 7 regardless of the RE position and number of CRSs.

 FIG. 9 shows the structure of subframes of one radio frame in the case of FDD and TDD. FIG. 10 shows the structure of uplink and downlink subframes according to TDD settings in case of TDD.

Referring to FIGS. 9 and 10, in the case of TDD, there are special subframes according to TDD configurations. For example, in the case of TDD setting 6, the special subframes of subframes 1 and 6 are divided into a downlink part (DwPTS), a guard period (GP), and an uplink part (UpPTS). The positions of the special subframes of the other TDD settings are as shown in FIG. 10 and are shown in Table 1 below.

On the other hand, the configuration of the special subframes may be 10, but not limited to, as shown in Table 2 below.

On the other hand, the ePDCCH is not mapped to the GP or UpPTS of the special subframe. In other words, the ePDCCH may not be mapped to the GP or UpPTS of the subframe 1 of the TDD configurations 3 to 6 and the subframes 1 and 6 of the TDD configurations 0 to 2 and 6 as shown in Table 2.

11 shows modulation methods in downlink transmission.

Referring to FIG. 11, QPSK, 16-QAM, 64QA can be used for the PDSCH with respect to modulation, but only QPSK can be used for the ePDCCH.

FIG. 12 shows a method of modulating PDSCH and ePDCCH in the data area (PDSCH area).

Referring to FIG. 12, QPSK, 16-QAM, and 64QA are used for the PDSCH in the data area (PDSCH region) and QPSK is used for the ePDCCH, so that the modulation methods for the same subframe may be the same, May not be the same.

eCCE of eREG The number of

eCCE can be formed by M (m is a natural number greater than 0 and less than 16) eREGs in centralized and distributed transmission. In centralized transmission, M = 4 in the normal subframe (normal CP) of the normal CP or special subframe configs 3, 4, 8 (normal CP) . I. E., Four eCCEs per PRB pair in a centralized transmission.

In the centralized transmission, special subframe configurations 1, 2, 6, 7 and 9 (special subframe configs 1,2,6,7,9 (normal CP)), normal subframe , And M = 8 in the case of 3,5,6 (extended CP). I.e., two eCCEs per PRB pair in a centralized transmission.

Table 3 shows the number of subcarriers and OFDM symbols of a normal CP and an extended CP.

The aggregate levels ( Aggregation levels )

Aggregation levels for ePDCCH may be 1, 2, 4 for centralized transmissions and 1, 2, 4, 8 for distributed transmissions.

In a normal subframe in the normal CP (normal subframe (normal CP) ) or the special sub-frame structure 3, 4, 8 (special subframe configs 3,4,8 (normal CP)) RE are available in the PRB pair X _{threshold value} (e.g. X _threshold (X _thresh) = 104) if equal to or smaller than the set of supported for ePDCCH level (aggregation levels), if the centralized transmission 2, 4, 8 can be, distributed transmission , It may be 2, 4, 8, 16, but is not limited to 32, 64, etc., and may be larger than 16. The X _threshold (X _thresh ) = 104 was derived to maintain a worst-case coding rate of approximately 0.8.

As described above, the total number of ePDCCH USS blind decoding per component carrier may be 32 or 48, depending on the configuration of the uplink MIMO.

13 is a conceptual diagram of a search space of an ePDCCH USS and CSS mapped to a data area (PDSCH area).

Referring to FIG. 13, for a subframe in which the UE monitors ePDCCH USS (UE-specific Search Space) in a given carrier, the UE may not monitor the PDCCH USS on the same carrier.

The UE may be implemented by monitoring concentrated or distributed ePDCCH candidates in a given subframe. Meanwhile, the UE may monitor both the centralized and distributed ePDCCH candidates in a given subframe. The UE may not increase the total number of USS blind decodings for carriers when monitoring both the centralized and distributed ePDCCH candidates in a given subframe.

Meanwhile, the UE may not monitor ePDCCH USS for at least the special subframe configurations 0 and 5 of the normal CP and the special subframe configurations 0 and 4 of the extended CP. However, the present invention is not limited to this and may indicate a subframe configuration in which the UE does not monitor the ePDCCH USS by higher layer signaling.

Meanwhile, the UE monitors the CSS on the PDCCH. If the ePDCCH CSS (Common Search Space) is set, the UE may monitor only the ePDCCH CSS, or both the PDCCH CSS and the ePDCCH CSS, or may monitor only one of the two, or at least one of the two according to the indication of the serving cell.

Meanwhile, the UE may monitor the PDCCH UCC and CSS in the same manner as before for the subframe configured not to monitor the ePDCCH.

When an arbitrary ePDCCH is transmitted through PRB # 1 for downlink scheduling for a specific UE and the PDSCH PRB allocation information included in the downlink scheduling includes PRB # 1 (for example, PRB # 0 to PRB # 3), the UE can perform the PDSCH transmission to the PRB # 1 and the PDSCH transmission only through the remaining PRBs (PRB # 0, # 2, # 3).

This means PDSCH transmission does not occur to any layer in the PRB (PRB # 1) in which the ePDCCH is transmitted even when the corresponding PDSCH transmission is transmitted in the form of spatial multiplexing (i.e., layer 2 transmission) . In other words, ePDCCH and PDSCH may not allow spatial multiplexing.

Figure 14 shows the mapping of the PRBs to the PUCCH.

Referring to FIG. 14, the PUCCH resource is located in the full-width geographical area of the entire available bandwidth. Each PUCCH resource is composed of 12 subcarriers (one RB) in each of two slots of one uplink subframe. In other words, one PUCCH resource composed of 12 subcarriers is located at the upper edge of the spectrum in the first slot of one subframe, and the same-sized resource is located at the lower edge of the spectrum in the second slot of the subframe.

On the other hand, the resource allocation of the PUCCH format 1a / 1b for the ePDCCH based HARQ-ACKs

) May be implicitly derived by the following equation (1).

Is the lowest eCCE index of the corresponding ePDCCH of the corresponding ePDCCH,

Is a quasi-PUCCH parameter,

May be a semi-static PUCCH resource starting offset for each ePDCCH set.

As can be seen from Equation (1) above, the index of the smallest eCCE of the corresponding ePDCCH may be an element of the PUCCH resource determination.

The PUCCH resource determination of the UE may be implemented with a semi-static PUCCH resource starting offset for each ePDCCH set. At this time, the eCCE can be indexed per ePDCCH set.

While it may or may not use the dynamically signaled PUCCH resource offset with the ePDCCH.

For the distributed ePDCCH, an antenna port index may be used, an antenna port index of an ePDCCH may be used, or an antenna port index of a PDSCH may be used.

resource allocation of PUCCH format 1a / 1b for ePDCCH based HARQ-ACKs when using dynamically signaled PUCCH resource offset with ePDCCH

) Can be derived by the following equation (2).

In Equation 2,

Is the PUCCH resource offset dynamically signaled to the ePDCCH for the implicit mapping between eCCE and PUCCH resources. This value may be provided to the terminal by bits of a specific field or a Dynamic Modifier, e. G. ARI, on the DCI at the ePDCCH.

As shown in Table 4, DCI formats 0 and 5 are for an uplink grant, DCI formats 3 and 3A are for uplink power control, and the rest are for downlink scheduling. Lt; / RTI >

DCI formats 0, 1A, 4, 2C may be supported for ePDCCH. On the other hand, all USS DCI formats may be provided for the ePDCCH and in this case all downlink transmission modes can be supported by the ePDCCH. On the other hand, it may not support a specific DCI format for ePDCCH.

15 is a block diagram showing a configuration of a base station according to an embodiment.

Referring to FIG. 15, a base station 800 includes a frequency resource allocation unit 810, a time resource allocation unit 820, and a transmission unit 830. The frequency resource allocation unit 810 and the time resource allocation unit 820 may be configured with one resource allocation unit that allocates frequency-time resources.

The frequency resource allocation unit 810 allocates frequency resources of resources for the control channel located in the data area in the manner described with reference to FIG. 2 to FIG.

The time resource allocation unit 820 allocates time resources of resources for the control channel located in the data region, with reference to FIG. 2 to FIG.

The transmission unit 830 transmits the control channel data (for example, PDCCH and PDSCH) for control and data to the control channel and the control channel set by the frequency resource allocation unit 810 and the time resource allocation unit 820, Lt; / RTI > In addition, the transmitter 830 may transmit the control channel setting information set by the frequency resource allocator 810 and the time resource allocator 820 to the terminal.

The frequency resource allocating unit 810 and the time resource allocating unit 820 are frequency-time resource allocating units for allocating a DM-RS (Demodulation Reference Signal) Sequentially mapping the indexes of Enhanced Resource Element Groups (EREGs) to resource elements except for the resource elements, and mapping one or more EREGs from one physical resource block pair or two or more physical resource block pairs to one And allocates a downlink control channel located in a data area composed of at least one ECCE.

The transmitting unit 830 may transmit the downlink control channel located in the data area to the base station.

16 is a block diagram showing a configuration of a terminal according to another embodiment.

Referring to FIG. 16, the terminal 900 includes a receiving unit 910 and a control information extracting unit 920.

The receiving unit 910 receives a downlink signal including a control channel.

The control information extracting unit 920 extracts a control channel located in the data area in the downlink signal.

The receiver 910 removes the resource elements for Demodulation Reference Signal (DM-RS) in order of frequency priorities in each physical resource block pair for each subframe, and sequentially adds EREG (Enhanced Resource Element Group) And one ECRE is formed by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs and a downlink control located in a data area composed of at least one ECCE Channel can be received.

The control information extracting unit 920 can obtain control information from the downlink control channel located in the data area.

17 is a flowchart showing a control channel transmission / reception method according to another embodiment.

17, the frequency resource allocation unit 810 and the time resource allocation unit 820 of the base station 800 may allocate a control channel for the control channel located in the data area, considering the system bandwidth and the average number of terminals in the intra- Resources are set (S1010). The resource setting for the control channel may include a setting for a resource block in which a control channel is located in a data area and a setting for a time resource (OFDM symbol) in which a control channel is located in a data block in a set resource block.

Next, the transmitting unit 820 of the base station 800 transmits resource setting information for the control channel to the terminal 900 (S1020). The base station 800 can transmit information to the terminal 900 through RRC signaling, a broadcast channel, and the like. The resource setting information transmitted from the base station 800 to the terminal 900 as setting information for the resource block may be a size of each group, an interval between groups, or an interval between resource blocks. The resource setting information transmitted from the base station 800 to the terminal 900 as setting information for a time resource may be a relative size to a control region, a size of an OFDM symbol unit, or a size of a slot unit.

Next, the transmitting unit 830 of the base station 800 maps the CCE to the resources for the set control channel and transmits the control information (S1030).

The control information extracting unit 920 of the terminal 900 places the control information for itself in the data area from the downlink data received by the receiving unit 910 based on the resource for the control channel located in the data area From the control channel (S1040).

For example, in step S1010, the BS removes the resource elements for demodulation reference signal (DM-RS) in a time order after frequency priority in each pair of physical resource blocks for each subframe, and sequentially applies EREG Enhanced Resource Element Group), and one ECRE is formed by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs, and a data area composed of at least one ECCE A downlink control channel can be allocated.

Next, in step S1030, the base station can transmit the downlink control channel located in the data area to the base station. In step S1030, the UE extracts Resource Elements for demodulation reference signal (DM-RS) in order of frequency priority and time order in each pair of physical resource blocks for each subframe, and sequentially assigns Enhanced Resource Element Group (EREG) And one ECRE is formed by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs and a downlink control located in a data area composed of at least one ECCE Channel can be received.

In step S1040, the UE can acquire control information from the DL control channel located in the data area.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (8)

For each subframe, the resource elements for DM-RS (Demodulation Reference Signal) are excluded in order of frequency priority and time order in each pair of physical resource blocks, and an index of EREG (Enhanced Resource Element Group) is sequentially mapped to the resource elements , Forming one ECCE by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs and allocating a downlink control channel located in a data area composed of at least one ECCE ; And
And transmitting a downlink control channel located in the data area to a base station. The method of claim 1,
And a downlink control channel located in the data area is composed of one, two, four, eight, or sixteen ECCEs. The method of claim 1,
In the case of TDD, the subframe is a subframe excluding a special subframe. The method of claim 1,
Transmitting a downlink control channel located in the data region to a base station;
The downlink control channel located in the data area is a control channel transmission method located in the data area of the base station, characterized in that modulated by QPSK. For each subframe, the resource elements for DM-RS (Demodulation Reference Signal) are excluded in order of frequency priority and time order in each pair of physical resource blocks, and an index of EREG (Enhanced Resource Element Group) is sequentially mapped to the resource elements , Forming one ECCE by four or eight EREGs from one physical resource block pair or two or more physical resource block pairs and receiving a downlink control channel located in a data area composed of at least one ECCE ; And
And receiving control information from a downlink control channel located in the data area. 6. The method of claim 5,
The downlink control channel located in the data region is one, two, four, eight, 16, one of the control channel receiving method located in the data region of the terminal, characterized in that consisting of one ECCE. 6. The method of claim 5,
In the case of TDD, the subframe is a subframe excluding a special subframe. 6. The method of claim 5,
Transmitting a downlink control channel located in the data region to a base station;
The downlink control channel located in the data area is a control channel receiving method located in the data area of the terminal, characterized in that modulated by QPSK.

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