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 in which a user equipment transmits a plurality of sounding reference signals to a base station in a wireless communication system. More particularly, the method comprises the steps of: generating a plurality of sounding reference signals on the basis of repetition factors (RPFs) corresponding to the number of transmitting antennas; multiplexing the plurality of sounding reference signals to a frequency domain in the same OFDM symbol or SC-FDMA symbol on the basis of a transmitting antenna index; and transmitting the multiplexed sounding reference signals to the base station using a plurality of transmitting antennas.

Abstract: A method of coordinating precoding matrixes in a wireless communication system is disclosed. A method of coordinating precoding matrixes by a base station in a wireless communication system comprises receiving precoding matrix index information from neighbor cells; and generating PMI allocation for each resource according to the precoding matrix index information wherein at least one PMI is restricted or recommended in part of resource in the PMI allocation for each resource.

Abstract: A method of transmitting and receiving channel state information feedback in a wireless communication system is disclosed. A method of transmitting channel state information (CSI) feedback by a user equipment receiver in a wireless communication system comprises mapping components of a CSI matrix to constellations; and allocating the mapped components to resource.

Abstract: Disclosed is a channel estimation method using a cooperative multi-point (CoMP) reference signal in a multi-cell environment. The method comprises a CoMP reference signal receiving step of enabling a terminal to receive, from each of the cells that perform a CoMP operation, a CoMP reference signal where an orthogonal code is applied to each of the cells; a channel estimation step of enabling the terminal to estimate, using said CoMP reference signal, channels of each of the cells which perform said CoMP operation; and a channel status feedback information transmitting step of enabling the terminal to transmit channel status feedback information to each of the cells.

Abstract: Provided are a method of information transmission performed by a transmitter in a wireless transmission system and an apparatus for same.

Abstract: An apparatus and method of transmitting ACK/NACK (acknowledgement/negative ACK) information in downlink and an apparatus and method of receiving the ACK/NACK information are disclosed. The present invention configures ACK/NACK information on multiple UL codeword transmission using a PHICH and at least one NDI, whereby the ACK/NACK information on the multiple UL codeword transmission is transmitted to a user equipment without additional PHICH resource allocation. The present invention extends the conventional HI codeword and/or arranged position on a signal constellation, thereby transmitting ACK/NACK information on multiple UL codeword transmission to a user equipment without additional PHICH resource allocation.

Abstract: The present invention relates to a method for generating an uplink reference signal in a system supporting plural uplink-access transmission modes. The method comprises: a step for transmitting the reference signal configuration information about the configuration of a reference signal from a base station to a user device through an uplink grant PDCCH (Physical Downlink Control Channel), and a step for receiving from the user device a sub-frame including the reference signal that is generated based on the reference signal configuration information. The reference signal configuration information is prepared for plural uplink access transmission modes and includes a cyclic shift value for the sequence of the reference signal. The reference signal is supposed to be transmitted to an uplink, and the user device is set up to be operated in the uplink-access transmission mode that corresponding to the reference signal configuration information.

Abstract: A method of sending data in a multiple antenna system according to an aspect of the present invention includes performing precoding on received symbols based on a second codebook generated from a first codebook for a plurality of transmission antennas and sending the precoded symbols. The second codebook is a codebook for transmission antennas which are a multiple of an integer of the plurality of transmission antennas, and a precoding matrix included in the second codebook is generated by a combination of precoding matrices included in the first codebook.

Abstract: A method of transmitting data using a plurality of subcarriers in a multi-antenna wireless communication system is disclosed. More specifically, the method includes receiving feedback information from a mobile station (MS), performing channel encoding and modulation independently on user data to be transmitted by each antenna using the received feedback information, determining a phase shift-based precoding matrix for increasing a phase angle of the user data by a fixed amount, and performing precoding using the determined phase shift-based precoding matrix on the user data.

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: A method for transmitting and receiving uplink signals using an optimized rank 3 codebook is disclosed. The optimized rank 3 codebook includes 12 precoding matrix groups, which are consisted of 6 Tx antenna power balanced precoding matrix groups and 6 layer power balanced precoding matrix groups. Preferably, the optimized 4Tx rank 3 codebook has 20 precoding matrix, two precoding matrixes are selected from each the 6 Tx antenna power balanced precoding matrix groups, considering chordal distance and the number of precoding matrix. And then 8 precoding matrices are selected from the layer balanced precoding matrix groups.

Abstract: A method of transmitting an uplink reference signal in a multiple antenna system is provided. A user equipment transmits a first sounding reference signal for uplink channel measurement on a first antenna by using at least one power amplifier among a plurality of power amplifiers, and transmits a second sounding reference signal for uplink channel measurement on a second antenna by using the at least one power amplifier, wherein the first sounding reference signal and the second sounding reference signal are transmitted using different time regions when using one power amplifier, and the first sounding reference signal and the second sounding reference signal are transmitted using different time regions or different frequency regions when using the plurality of power amplifiers.

Abstract: A method of transmitting data in a wireless communication system is provided. A user equipment receives an antenna group selection indicator indicating an antenna group comprising two or more activated transmit antennas among a plurality of transmit antennas, selects a transmit antenna to be activated according to the antenna group selection indicator, and transmits the data by supplying power to a power amplifier corresponding to the selected transmit antenna, wherein the number of power amplifiers is less than the number of transmit antennas and a type of the antenna group is determined according to the number of the power amplifiers. Accordingly, information on an antenna group in use among a plurality of antennas can be effectively transmitted.

Abstract: A method for a user equipment to precode and transmit an uplink signal efficiently in a 4-antenna system and a method for a base station to receive the transmitted signal efficiently are disclosed. Four antennas of a user equipment can be grouped by a 2-antenna unit. In consideration of this antenna group, it is able to perform precoding using antenna selection/DFT matrix of the antenna group unit. Moreover, a rank-3 codebook can be configured to include a precoding matrix of a type in consideration of power balance per antenna and a precoding matrix including one non-zero component only in one row for maintaining a good CM property.

Abstract: A method of transmitting feedback data in a multiple antenna system includes generating feedback data based on the channel information and transmitting the feedback data at transmission periods, wherein the feedback data is transmitted in a plurality of report types respectively having a different control signal type contained depending on the transmission periods.

Abstract: A method for transmitting a downlink control channel in a mobile communication system and a method for mapping the control channel to physical resources using a block interleaver are provided. In order to transmit a downlink control channel in a mobile communication system, information bits are modulated to generate one or more modulation symbols according to a specific modulation scheme, the modulation symbols are interleaved using a block interleaver, and the interleaved modulated symbols are mapped to resource elements allocated for transmission of at least one control channel in a subframe, thereby transmitting the at least one control channel.

Abstract: A method of transmitting control signals includes configuring a multiplexing indicator indicating that a plurality of control signals are multiplexed on a control channel, generating a multiplexed control signal by multiplexing a first control signal and a second control signal according to the multiplexing indicator and transmitting the multiplexed control signal on the control channel. Overhead due to control signaling can be reduced by transmitting a multiplexed control signal on a control channel.

Abstract: A method for multiplexing a data information stream, including a systematic symbol and a non-systematic symbol, and a control information stream of at least three types in a wireless mobile communication system is disclosed. The method includes mapping the data information stream to a resource area so that the systematic symbol is not mapped to a specific resource area to which the control information stream is mapped, and mapping the control information stream to the specific resource area.

Abstract: A method for efficiently transmitting and receiving downlink control information is disclosed. The method includes, at an base station, receiving feedback information including a preceding matrix index (PMI) from an user equipment (UE) and transmitting precoding information having a predetermined bit number according to the number of antenna ports and a transmission mode of the base station. The preceding information of a predetermined transmission mode in the preceding information includes confirmation information indicating that the base station uses a PMI which is recently received from the UE. At this time, if the confirmation information is transmitted via a specific resource block (RB) of an nth subframe, the PMI which is recently received is received via a resource block of an n?xth subframe or a subframe prior to the n?xth subframe corresponding to the specific resource block. In addition, “x” is a predetermined integer or an integer determined by upper layer signaling of a physical layer or higher.