Abstract: A method of transmitting a feedback message in wireless communication system is provided. The method includes selecting N best subbands of M subbands according to CQI, where both M and N are a natural number and M is larger than N, generating multiple input multiple output (MIMO) information comprising N codebook indexes and N differential CQIs and transmitting the feedback message comprising the MIMO information.

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: The present invention provides a method for reference signal dropping and an apparatus for the method.

Abstract: Provided are a method and apparatus for measuring interference in a wireless communication system. A terminal receives, from a base station, a zero-power channel state information (CSI) reference signal (RS) indicator that indicates whether or not to estimate interference using a zero-power CSI RS signal, and, according to the zero-power CSI RS indicator, measures interference on the basis of the zero-power CSI RS.

Abstract: Disclosed is a method for transmitting a CoMP reference signal for accurate channel estimation. The CoMP reference signal to be transmitted to a terminal which performs a CoMP operation in a multi-cell environment is a cell-specific reference signal or a CoMP-zone-specific reference signal. A method for transmitting the cell-specific reference signal uses an ID of a CoMP set constituted by cells that perform a CoMP operation, or does not apply a frequency shift value while using the ID of a relevant cell, or uses an ID of a serving cell or a frequency shift value of the serving cell. The cell-specific reference signal is transmitted using a preset specific resource region. A method for transmitting the CoMP-zone-specific reference signal is configured such that the pattern of the sequence of CoMP reference signals varies in each of the CoMP zones, and the pattern can be set in advance.

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 is a method of transmitting a signal of a multi-node system employing a plurality of nodes and a plurality of base stations that can be controlled by being connected with the plurality of nodes. The method includes: mapping at least one base station among the plurality of base stations to at least one node among the plurality of nodes; and transmitting by the at least one base station a signal to a user equipment via the mapped node, wherein the plurality of nodes are installed in a geographically distributed manner, and the node mapped to the at least one base station varies temporally.

Abstract: A method of transmitting a reference signal by a base station in a wireless communication system is provided. The method includes: generating a plurality of reference signals for channel measurement, wherein the plurality of reference signals for channel measurement are different types; and transmitting the plurality of reference signals for channel measurement, wherein the plurality of reference signals for channel measurement are transmitted using one or more subframes as a duty cycle.

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 wireless communication system and provides an efficient control information transmission method and apparatus for supporting a multiple antenna transmission technique. A method is provided for transmitting downlink hybrid automatic repeat request (HARQ) information related to an uplink multiple codeword transmission and includes receiving the uplink multiple codeword transmission, generating HARQ information related to each of the multiple codewords based on a result of decoding each of the multiple codewords, modulating the HARQ information, and transmitting the modulated HARQ information via one or more physical HARQ indicator channels (PHICHs).

Abstract: The present invention relates to a method for receiving a signal through a terminal in a distributed antenna system (DAS) comprising the steps of: receiving composition information of a local midamble corresponding to a terminal or a terminal group including the terminal from a base station which belongs to the DAS; and receiving the local midamble from the base station, and the local midamble can be a midamble corresponding to one or more effective transmission antennas associated with the terminal or the terminal group of a plurality of antennas of the base station.

Abstract: A method and an apparatus for feedback transmission in a wireless communication system are provided. A terminal receives information about a short-term feedback period and a long-term feedback period from a base station, and then transmits to the base station short-term feedback information per short-term feedback period or long-term feedback information per long-term feedback period over a primary fast feedback channel (PFBSCH). The long-term feedback information contains an index of a subband subjected to channel measurement and a difference in measurement values that is a difference between a reference channel measurement value and a channel measurement value being measured.

Abstract: A method and apparatus of allocating a bandwidth request channel (BRCH) in a wireless communication system including a relay station (RS) is provided. At least one first BRCH for a bandwidth request of a mobile station (MS) connected to a base station (BS) and at least one second BRCH for a bandwidth request of the RS are allocated. An opportunity index is assigned to each of the at least one first BRCH and the at least one second BRCH, and the opportunity index assigned to the at least one second BRCH is started after the opportunity index assigned to the at least one first BRCH.

Abstract: A method and apparatus for transmitting a signal in a wireless communication system are provided. The method includes: generating R spatial stream each of which is generated on the basis of an information stream and reference signal; generating N transmit streams on the basis of the R spatial streams and a precoding matrix (where R<N); mapping the N transmit streams to at least one resource block; and generating N signals from the N transmit streams mapped to the at least one resource block, and the transmitting the N signals to a user equipment through respective antennas.

Abstract: A method for reducing inter-cell interference and a method for transmitting a signal by a collaborative MIMO scheme, in a communication system having a multi-cell environment are disclosed. An example of a method for transmitting, by a mobile station, precoding information in a collaborative MIMO communication system includes determining a precoding matrix set including precoding matrices of one more base stations including a serving base station, based on signal strength of the serving base station, and transmitting information about the precoding matrix set to the serving base station. A mobile station in an edge of a cell performs a collaborative MIMO mode or inter-cell interference mitigation mode using the information about the precoding matrix set collaboratively with neighboring base stations.

Abstract: A method for estimating channel state in a wireless communication system and a mobile station using the same are disclosed. The method includes acquiring cell Identifiers (IDs) of a serving cell and one or more neighbor cells, acquiring information about preset power level patterns for one or more frequency partitions to which FFR is applied according to the cell IDs, and estimating a channel state of the serving cell based on the power level pattern information.

Abstract: The present invention relates to a method and apparatus for transmitting/receiving data in a wireless communication system. According to one aspect of the present invention, a data receiving method is provided wherein a mobile station in a wireless communication system uses a frame including a first subframe in which a physical downlink shared channel (hereinafter, referred to as “PDSCH”) includes a first cyclic prefix (hereinafter, referred to as “CP”) and a second subframe in which the PDSCH includes a second CP, wherein the data receiving method comprises a step in which the mobile station receives information on the length of the first CP from a base station, receives data from the base station through the first subframe, and removes the CP of the data using the information on the length of the first CP. The first CP and the second CP have different lengths.

Abstract: The present invention relates to a wireless communication system. More particularly, the present invention relates to a method and apparatus which indicate, using multiple CQIs, channel quality in the event multiple users are scheduled in the same time/frequency area, and to a method and apparatus which estimate a channel state using said multiple CQIs. According to the embodiments of the present invention, a channel state can be estimated in a more accurate manner in a multi-user MIMO system.

Abstract: Provided are a method and apparatus for measuring interference in a wireless communication system. A terminal receives, from a base station, a zero-power channel state information (CSI) reference signal (RS) indicator that indicates whether or not to estimate interference using a zero-power CSI RS signal, and, according to the zero-power CSI RS indicator, measures interference on the basis of the zero-power CSI RS.

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.