Abstract: A method of performing cooperative transmission in a multi-node system including a Base Station (BS) and a plurality of nodes controlled by the BS is provided. The method comprises: transmitting a first signal generated using a first cell identifier (ID) from the plurality of nodes; and transmitting a second signal generated using a second cell ID from at least one of the plurality of nodes, wherein the first cell ID is identical with a cell ID used by the BS, and the second cell ID is different from the first cell ID.

Abstract: Provided is a method of searching for control information of a user equipment (UE) in a multi-node system including a plurality of nodes and a base station connected to each of the plurality of nodes and capable of controlling the nodes. The method includes: receiving search space indication information from the base station; and searching for the control information in a radio resource region indicated by the search space indication information, wherein the search space indication information indicates any one of a first search space and a second search space.

Abstract: The present invention relates to a method in which a user equipment receives a downlink signal from a base station in a wireless communication system that supports downlink mimo transmission according to one embodiment of the present invention comprises: receiving downlink control information that includes information indicative of the number of layers (n, 1?n?8) where one or two enabled code words of the downlink mimo transmission are mapped; on the basis of the downlink control information, receiving downlink data transmitted over the respective n layers and a ue-specific reference signal for each of the n layers; and decoding the downlink data on the basis of the ue-specific reference signals, wherein the information indicative of the number of layers can further include information on a code for identifying the ue-specific reference signals.

Abstract: A method of generating reference signals by a base station in a wireless communication system is disclosed. The method including a sequence of a first reference signal using a cell identifier of the base station, transmitting, to a first user equipment (UE), a message including mode information indicating a first mode for a coordinated multi-point (CoMP) operation and a predetermined identifier being different from the cell identifier of the base station and generating a sequence of a second reference signal for the first UE using the predetermined identifier instead of the cell identifier of the base station.

Abstract: A method and an apparatus of receiving data, the method carried in a user equipment (UE) configured to communicate with a first cell and a second cell, are provided. The method includes: receiving a first downlink data through a first downlink channel from the first cell, receiving a second downlink data through a second downlink channel from the second cell, and transmitting a data on a third channel, wherein the data transmitted on the third channel is related to a HARQ operation, and wherein the third channel is used to transmit the data related to the HARQ operation with respect to both the first data and the second data which have been received from the first and second cells, respectively.

Abstract: According to one aspect of the present invention, antennas or antenna nodes spaced away from each other by a predetermined distance or more are configured to be able to transmit control information of mutually different user equipment groups, thereby increasing the efficiency in the operation of control channels. In addition, according to another aspect of the present invention, a resource region for transmitting control information for an improved user equipment, which is a target of a multi-node cooperative transmission, is set differently from a resource region for transmitting control information for a legacy user equipment, thereby increasing the efficiency in the transmission of the control information for the improved user equipment.

Abstract: A technique for receiving and transmitting downlink reference signals is disclosed. When transmitting downlink data demodulation reference signals (DMRS) (or reference signals for downlink data demodulation) by using two or more layers, the DMRS of each layer may be multiplexed by using a code division multiplexing method and then transmitted. The DMRS for each of the two or more layers may be used for one user equipment or for two or more user equipments. And, downlink control signals for transmitting and receiving such DMRS may be configured to have the same format regardless of a single-user mode (or SU-MIMO mode) or a multi-user mode (or MU-MIMO mode), thereby being used.

Abstract: A method is provided for receiving aperiodic channel state information (CSI). A base station (BS) transmits, to a user equipment (UE), an uplink downlink control information (DCI) format. The BS receives, from the UE, aperiodic CSI through a physical uplink shared channel (PUSCH) if the BS triggers an aperiodic CSI report using a CSI request field included in the uplink DCI format. The CSI request field is either a 1-bit field or a multi-bit field. When the UE is configured with only one cell, the 1-bit field is included in the uplink DCI. When the UE is configured with more than one channel state information-reference signal (CSI-RS), the multi-bit field is included in the uplink DCI.

Abstract: A method for correcting errors in a multiple antenna system based on a plurality of sub-carriers and a transmitting/receiving apparatus supporting the same are disclosed. The method includes determining a phase shift based precoding matrix phase shifted at a predetermined phase angle, initially transmitting each sub-carrier symbol to a receiver in a packet unit by using the phase shift based precoding matrix, reconstructing the phase shift based precoding matrix to reduce a spatial multiplexing rate if a negative reception acknowledgement (NACK) is received from the receiver, and retransmitting the initially transmitted sub-carrier symbol by using the reconstructed phase shift based precoding matrix or by changing the phase shift based precoding matrix using offset information fed back from the receiver or random offset information.

Abstract: The present invention relates to a method in which a user equipment receives a downlink signal from a base station in a wireless communication system that supports downlink mimo transmission according to one embodiment of the present invention comprises: receiving downlink control information that includes information indicative of the number of layers (n, 1?n?8) where one or two enabled code words of the downlink mimo transmission are mapped; on the basis of the downlink control information, receiving downlink data transmitted over the respective n layers and a ue-specific reference signal for each of the n layers; and decoding the downlink data on the basis of the ue-specific reference signals, wherein the information indicative of the number of layers can further include information on a code for identifying the ue-specific reference signals.

Abstract: Provided are a method and an apparatus for allocating a control channel in a wireless communication system. A base station allocates an enhanced physical downlink control channel (e-PDCCH) to a localized region within a physical downlink shared channel (PDSCH) region, allocates the e-PDCCH to a distributed region within the PDSCH region, and transmits a scheduling assignment via the allocated e-PDCCH.

Abstract: A method is provided for receiving a downlink control channel in a wireless communication system. A user equipment performs a blind decoding in a first search space on the cell to find a first Physical Downlink Control Channel (PDCCH). The user equipment receives a Radio Resource Control (RRC) message including information on a second search space for monitoring a second PDCCH and identity information, and performs a blind decoding in the second search space on the cell to find the second PDCCH. The first PDCCH is demodulated based on a physical cell identity of the cell, and the second PDCCH is demodulated based on the identity information instead of the physical cell identity.

Abstract: A method and a base station (BS) for receiving channel state information are discussed. The method according to an embodiment includes transmitting a radio resource control (RRC) signal to a user equipment (UE), the RRC signal including a plurality of configurations for periodic channel state information (CSI) reports; transmitting, to the UE, a plurality of CSI reference signals (CSI-RSs); and receiving, from the UE, generated CSI for the plurality of CSI-RSs based on the RRC signal. Each of the plurality of configurations for the periodic CSI reports includes an indicator indicating an uplink subframe to be used, by the UE, for transmitting CSI corresponding to a specific one of the periodic CSI reports.

Abstract: A method of transmitting an uplink reference signal of a user equipment (UE) in a multi-node system is described. The method according to an embodiment includes receiving a synchronization signal from a node; receiving a parameter for a virtual cell identifier (ID) from the node; generating an uplink demodulation reference signal (DM-RS) using the parameter for the virtual cell ID; and transmitting the generated uplink DM-RS to the node. A physical cell ID is a cell ID obtained from the synchronization signal, and the parameter for the virtual cell ID is a parameter used for generating the uplink DM-RS in the replacement of the physical cell ID.

Abstract: A technique for receiving and transmitting downlink reference signals is disclosed. When transmitting downlink data demodulation reference signals (DMRS) (or reference signals for downlink data demodulation) by using two or more layers, the DMRS of each layer may be multiplexed by using a code division multiplexing method and then transmitted. The DMRS for each of the two or more layers may be used for one user equipment or for two or more user equipments. And, downlink control signals for transmitting and receiving such DMRS may be configured to have the same format regardless of a single-user mode (or SU-MIMO mode) or a multi-user mode (or MU-MIMO mode), thereby being used.

Abstract: A method and apparatus for transmitting a downlink signal in a multiple input multiple output (MIMO) wireless communication system is disclosed. A method for receiving a downlink signal from a base station to a user equipment in a multiple input multiple output (MIMO) system, which supports dual layer transmission based on first and second antenna ports, comprises receiving downlink control information (DCI) through a downlink control channel; and receiving downlink data through a downlink data channel, the downlink data including one or more of a first transport block and a second transport block, wherein the downlink control information includes a new data indicator (NDI) for each of the first and second transport blocks, and if the first transport block is disabled and the second transport block is enabled, the new data indicator for the first transport block indicates an antenna port through which the second transport block is received.

Abstract: A method is presented for receiving aperiodic channel state information (CSI). A base station (BS) transmits a CSI request field which is set to trigger a CSI report to a user equipment (UE). The BS 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. 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.

Abstract: A method of measuring interference to perform efficient data communication is disclosed. A method of measuring interference of neighboring cells comprises allocating one or more first resource elements, to which pilot signals are allocated, to predetermined symbol regions included in a first resource block; allocating one or more second resource elements for measuring interference of the neighboring cells to a first symbol region of the predetermined symbol regions; and measuring interference of the neighboring cells using the one or more second resource elements.

Abstract: Provided are a method and an apparatus for control channel decoding of a terminal in a multi-node system. The method sets a search space for searching a control channel and can perform the decoding by using different demodulation methods according to aggregation levels capable of constituting the control channel within the search space. In addition, the method determines the DCI format to be searched according to a transmission mode and can use different demodulation methods according to the determined DCI format. Furthermore, the method modulates DCI format to a first modulation degree when demodulating the DCI format, and can demodulate the DCI format to a second modulation degree when the DCI format is not detected.

Abstract: Provided are a method and apparatus for a UE (user equipment) to provide reference signal feedback in a wireless communication system. The method includes: receiving, from a base station, CSI-RS configuration information for configuring CSI-RS (channel state information reference signal) patterns, the CSI-RS configuration information containing usage information; performing a first measurement for radio resource management on all CSI-RS patterns configured based on the CSI-RS configuration information; and performing a second measurement only on CSI-RS patterns corresponding to the usage information, the second measurement being determined by the usage indicated by the usage information.