Abstract: A method for transmitting a reference signal in a multi-antenna system is provided. The method includes: selecting at least one orthogonal frequency division multiplexing (OFDM) symbol in a subframe containing a plurality of OFDM symbols; allocating a channel quality indication reference signal (CQI RS) capable of measuring a channel state for each of a plurality of antennas to the selected at least one OFDM symbol; and transmitting the CQI RS, wherein the CQI RS is allocated to an OFDM symbol which does not overlap with an OFDM symbol to which a common reference signal to be transmitted to all user equipments in a cell or a dedicated reference signal to be transmitted to a specific user equipment in the cell is allocated.

Abstract: The present invention relates to a method for transmitting an uplink reference signal in a multi-node system and a terminal using same. The method comprises the steps of: receiving a synchronization signal from a node; receiving parameters for a virtual cell identifier (ID) from the node; generating an uplink demodulation reference signal (DM-RS) using the parameters for the virtual cell ID; and transmitting the generated uplink DM-RS to the node, wherein a physical cell ID is a cell ID obtained from the synchronization signal, and the parameters for the virtual cell ID are parameters used for generating the uplink DM-RS in the replacement of the physical cell ID.

Abstract: A method and an apparatus for transmitting data in a wireless communication system are provided. A base station transmits to a terminal a physical downlink control channel (PDCCH) through a macro node, and transmits a physical downlink shared channel (PDSCH) through at least one radio remote head (RRH) having a cell identity (ID) that is identical to the macro node, so as not to overlap in with the PDCCH in a time domain. A time gap can be set between a last orthogonal frequency division multiplexing (OFDM) symbol to which the PDCCH is allocated and a first OFDM symbol to which the PDSCH is allocated.

Abstract: There are provided a method of user equipment searching for control information and an apparatus using the same. The method includes receiving information about the position of an Enhanced-Physical Control Format Indication Channel (E-PCFICH) from a base station, receiving an E-PCFICH based on the information about the position of the E-PCFICH, obtaining information about the frequency band of an Enhanced Physical Downlink Control Channel (E-PDCCH) region through the E-PCFICH, and searching the E-PDCCH region for an E-PDCCH for the user equipment, wherein the E-PCFICH is transmitted in an OFDM symbol between a Physical Downlink Control Channel (PDCCH), transmitted in the first N (N is one of natural numbers 1 to 4) Orthogonal Frequency Division Multiplexing (OFDM) symbols of a subframe in the time domain, and the E-PDCCH region.

Abstract: An interference removal method in a multi-node system is provided. A user equipment (UE) receives node information from a base station, a first signal from a first node, and a second signal from a second node. The first signal and the second signal are used to remove an interference. The node information includes configuration information related to the first signal and the second signal. The configuration information includes information related to at least one of a number of antenna ports of the first node and the second node, a number of data streams, and a node identifier (ID). A pattern of the first signal or the second signal is determined according to at least one of the number of antenna ports of the first node and the second node, the number of data streams, and the node ID.

Abstract: A method performed by a base station (BS) is provided for receiving aperiodic channel state information (CSI). The BS transmits a CSI request field which is set to trigger a CSI report to a user equipment (UE), and receives CSI through a physical uplink shared channel (PUSCH) from the UE. The CSI request field has a value among a plurality of candidate values and the plurality of candidate values comprises a first value which triggers an aperiodic CSI report for a first set of reference signals and a second value which triggers an aperiodic CSI report for a second set of reference signals. The first set and the second set of reference signals are configured by a higher layer signal.

Abstract: Disclosed is a method and apparatus for searching for a user equipment searching for a control channel in a multi-node system. The method comprises: searching inside an E-PDCCH region for a first piece of downlink control information (DCI), which is determined according to a transmission mode; and searching inside the E-PDCCH region for a second piece of DCI, regardless of the transmission mode, wherein the E-PDCCH region is a control channel region to which the DCI, which is decoded on the basis of a user equipment-specific reference signal (URS), is transmitted from a subframe comprising a plurality of orthogonal frequency division multiplexing (OFDM) symbols.

Abstract: The present invention relates to a terminal which receives signals from a base station, and to a method in which the terminal receives signals from the base station in a distributed antenna system (DAS). The terminal receives, from the base station having a plurality of antennas, control information on one or more active transmission antennas allocated to the terminal, from among the plurality of antennas, and receives signals from the base station via said one or more active transmission antennas.

Abstract: A method for transmitting a channel status information reference signals (CSI-RSs) for a maximum of eight antenna ports includes mapping the CSI-RSs for a maximum of eight antenna ports onto a data region of a downlink subframe having a normal cyclic prefix (CP) configuration according to a predetermined pattern; and transmitting the downlink subframe to which the CSI-RSs mapped, wherein the predetermined pattern defines the CSI-RSs to be mapped onto two OFDM symbols of the data region in the downlink subframe and mapped to at least one of four subcarrier positions in each of the two OFDM symbols, and wherein the four subcarrier positions defined by the predetermined pattern may be two consecutive subcarrier positions and two other consecutive subcarrier positions spaced apart by four subcarriers.

Abstract: The present invention relates a method in which a base station transmits a downlink signal by using a plurality of layers comprises the steps of: multiplexing and transmitting dedicated reference signals for the plurality of layers on the basis of a reference signal pattern, wherein 24 resource element positions comprised in the reference signal pattern are set as 6 groups, the 6 groups are set as 2 high-level groups, the reference signal for the plurality of layer is split and placed in the 2 high-level groups, and the reference signal for 2 or more layers placed in the same group is subjected to code-division multiplexing.

Abstract: Provided is a method for transmitting feedback information of a UE in a distributed antenna system in which a plurality of antennas are distributedly disposed within a cell is provided. The method includes transmitting first feedback information used for a base station (BS) to allocate at least one of a plurality of antennas to a UE, to the BS; receiving antenna allocation information determined based on the first feedback information from the BS; and transmitting second feedback information indicating a channel state with respect to an antenna allocated according to the antenna allocation information to the BS.

Abstract: A method for a base station to transmit a channel-state-information reference signal for up to 8 antenna ports includes mapping, in accordance with a predetermined pattern, the channel-state-information reference signal for up to 8 antenna ports onto a data region of a downlink subframe having an extended cyclic prefix (CP) structure, and transmitting the downlink subframe onto which the channel-state-information reference signal for up to 8 antenna ports has been mapped; and, in the predetermined pattern, the channel-state-information reference signal for up to 8 antenna ports in mapped onto 2 OFDM symbols on the data region of the downlink subframe, with a definition for mapping onto at least one of 4 subcarrier wave positions in each of the 2 OFDM symbols, and the 4 subcarrier wave positions defined in the predetermined pattern can be disposed at 3 subcarrier wave intervals.

Abstract: A method and an apparatus for transmitting feedback of a mobile station (MS) in a wireless communication system supporting a multi-carrier operation are provided. The method includes transmitting feedback information to a base station, and in this case, the feedback information is transmitted through a MAC control message and the feedback information includes carrier information of an activation carrier related to the MAC control message.

Abstract: Disclosed is a method of operating a terminal in a communication system, including measuring channel quality, and transmitting a Channel Quality Indicator (CQI) based on the channel quality measured on the basis of a target BLock Error Rate (BLER), which is determined by using a ratio between efficiency corresponding to a first CQI and efficiency corresponding to a second CQI.

Abstract: The present invention relates to a method and apparatus for measuring interference in a wireless communication system. User equipment (UE) receives a common reference signal (CRS) from a first domain having the same cell identity and a channel state information (CSI) reference signal (RS) from a second domain including a configuration of the CSI RS designated by the UE. The UE measures interference for the second domain on the basis of the received CRS and CSI RS.

Abstract: According to the disclosure of the present description, a method in which a terminal cooperates with another terminal to transmit data to a base station is provided. The method comprises the following steps: if data to be transmitted to a base station exists, mutually exchanging data with another cooperative terminal which belongs to the same cooperative cluster; transmitting, to the base station, a request message for an allocation of an uplink resource for transmitting the data; receiving, from the base station, a permission message for the uplink resource; and, upon receipt of the permission message, transmitting the data and data of said other terminal using the uplink resource in accordance with the permission message.

Abstract: An apparatus and method for controlling inter-cell interference is disclosed. The user equipment for controlling inter-cell interference in a wireless communication system includes an interference level measuring module configured to measure interference levels of neighboring cells using at least one of information about the number of antennas among antennas deployed in the neighboring cells, information about indexes of the effective antennas, and information about reference signal of the neighboring cells, an interference restriction request determination module configured to compare the interference levels of the neighboring cells with a predetermined threshold and to determine whether or not UE requests an interference restriction to the neighboring cells, and a transmitter configured to transmit information about one or more neighboring cells, to which the interference restriction request will be transmitted, to a serving base station.

Abstract: Provided are a resource allocation method and device in a multi-node system comprising a plurality of nodes and a base station which is connected to each of the plurality of nodes and controls same. The method comprises: partitioning wireless resources which the base station can use; and allocating the partitioned wireless resources to the plurality of nodes, respectively, wherein the wireless resources allocated to the plurality of nodes, respectively, have different frequency bands or frame structures between the nodes which may cause interference.

Abstract: A method and apparatus of feeding back channel state information in a multi-node system are provided. The method includes receiving a reference signal of N nodes, wherein N is a natural number equal to or more than 2, aligning the N nodes in an order of preferring the N nodes based on a result of measuring the reference signal, generating channel state information for the aligned nodes, and transmitting the generated channel state information to the base station, wherein the channel state information is generated with respect to N node combinations configured from the aligned nodes, and wherein the N node combinations are obtained by adding next highest-priority nodes to a first node combination one by one, the first node combination consisting a highest-priority node among the aligned nodes.

Abstract: A method of transmitting data in a wireless communication system is provided. The method includes generating duplicate data by using repetition coding, the duplicate data being the same as original data, shifting the phase of the duplicate data, and transmitting the original data and the phase-shifted duplicate data. The duplicate data is mapped to a modulation symbol having a different size or phase as that of the original data, thus to reduce the PAPR unlike the general repetition coding.