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: 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: 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 of transmitting, by a transmitter, information in a wireless communication system, the method includes generating first and second symbols; generating first and second transmit vectors on the basis of an Alamouti code from the first and second symbols; and transmitting the first transmit vector through a first antenna and transmitting the second transmit vector through a second antenna. The first transmit vector consists of a first transmit symbol and a second transmit symbol. The second transmit vector consists of a third transmit symbol and a fourth transmit symbol. The first, second, third, and fourth transmit symbols are transmitted based on first and second resource indexes. The first symbol is a first modulation symbol for first information, and the second symbol is a second modulation symbol for second information.

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 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: A method of transmitting, by a transmitter, information in a wireless communication system, the method includes generating first and second symbols; generating first and second transmit vectors on the basis of an Alamouti code from the first and second symbols; and transmitting the first transmit vector through a first antenna and transmitting the second transmit vector through a second antenna. The first transmit vector consists of a first transmit symbol and a second transmit symbol. The second transmit vector consists of a third transmit symbol and a fourth transmit symbol. The first, second, third, and fourth transmit symbols are transmitted based on first and second resource indexes. The first symbol is a first modulation symbol for first information, and the second symbol is a second modulation symbol for second information.

Abstract: A method and apparatus for transmitting a signal in a wireless communication system are provided. The method includes: generating R spatial streams each of which is generated on the basis of an information stream and a 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 transmitting the N signals to a user equipment through respective antennas.

Abstract: Disclosed is a method for transmitting a CoMP reference signal for accurate channel estimation. The CoMP reference signal is a cell-specific reference signal or a CoMP-zone-specific reference signal. A method for transmitting the cell-specific reference signal uses a CoMP set ID or does not apply a frequency shift value, or uses a serving cell ID or a frequency shift value of the serving cell. The cell-specific reference signal is transmitted using a preset 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. The reference signal is multiplexed using an orthogonal code and transmitted to plural terminals using the same CoMP zone.

Abstract: A method of transmitting a signal from a base station to a user equipment in a multi-node system comprises down-link-transmitting a signal at a first zone of a radio frame by using centralized antennas (CAs); and downlink-transmitting a signal at a second zone used for a backhaul link of a relay in the radio frame by using distributed nodes, wherein the first zone and the second zone are multiplexed by time division.

Abstract: A method of transmitting, by a transmitter, information in a wireless communication system, the method includes generating first and second symbols; generating first and second transmit vectors on the basis of an Alamouti code from the first and second symbols; and transmitting the first transmit vector through a first antenna and transmitting the second transmit vector through a second antenna. The first transmit vector consists of a first transmit symbol and a second transmit symbol. The second transmit vector consists of a third transmit symbol and a fourth transmit symbol. The first, second, third, and fourth transmit symbols are transmitted based on first and second resource indexes. The first symbol is a first modulation symbol for first information, and the second symbol is a second modulation symbol for second information.

Abstract: The present invention relates to a precoding matrix information transmission method and a user device, and provides a method for transmitting precoding matrix information by a particular user device among user devices that receive a signal transmitted from one base station. The method comprises the steps of: determining, from a predetermined codebook, a first precoding matrix which is a precoding matrix for the particular user device during signal reception, and determining one or more second precoding matrices for the other user devices which are to be multiplexed in a predetermined resource region with the particular user device, wherein the one or more second precoding matrices are determined within a codebook subset of the predetermined codebook linked with the first precoding matrix; and transmitting, to the base station, first precoding matrix information indicating the first precoding matrix and second precoding matrix information indicating the one or more second precoding matrices.

Abstract: The present invention relates to a method for mitigating inter-cell interference in a multi-cell DAS. In one embodiment of the present invention, user equipment estimates an interfering antenna of an adjacent cell on the basis of RS pattern information of the adjacent cell, provided by a base station of a serving cell, or the base station provides the user equipment with information which specifies an interfering cell of the adjacent cell.

Abstract: Disclosed is a method for efficiently transceiving information required for implementing a multi-cell-based CoMP MU-MIMO scheme. For this purpose, a base station which performs CoMP operation generates: (A) a reference signal sequence on the basis of a specific base station; or generates (B) the same reference signal sequence on the basis of a CoMP ID, and transmits the generated sequence to user equipment. To support an MU-MIMO scheme and to perform a joint processing method, the base station must additionally transmit CoMP reference signal sequence information, frequency shift information, etc. to the user equipment in said (A) case, and generates a CoMP reference signal on the basis of a preset CoMP set ID and transmits the generated signal to the user equipment in said (B) case.

Abstract: The present invention provides a data transmission device and method in a wireless communication system. The device comprises a processor which is connected with the M antennas and which is formed so as to generate data to be transmitted through the M antennas, on the basis of a precoding matrix; the precoding matrix is generated based on a plurality of matrices; and a first matrix, which is one matrix among the plurality of matrices, is selected from within a codebook for N antennas (where N<M).

Abstract: The present invention relates to a wireless communication system, and an adaptive multiple antenna transmission method and apparatus in accordance with antenna transmission power are disclosed. A method of performing multiple antenna transmission from a terminal to a base station according to one embodiment of the present invention may include the steps of: determining a reference value for a transmission power of each of a plurality of transmit antennas of the terminal; grouping the plurality of transmit antennas into a first group of transmit antennas and a second group of transmit antennas in accordance with the determined reference value; and transmitting a signal to the base station through at least one of the first group of the transmit antennas and the second group of transmit antennas.

Abstract: The present invention relates to a wireless communication system, and provides a method and an apparatus for transmitting a downlink reference signal in the wireless communication system. The method for enabling a base station to transmit the reference signal to a terminal using layers of 8 or less in accordance with one embodiment of the present invention comprises the steps of: transmitting data for the layers of 8 or less through a data domain of a downlink sub frame; and transmitting a reference signal for the layers of 8 or less on a fixed OFDM symbol of the downlink sub frame, wherein the reference signal is a DRS (Dedicated Reference Signal) which demodulates the data for the layers of 8 or less, and the reference signal for the layers of 8 or less is separated into 1st and 2nd groups, and reference signals of the 1st and 2nd groups can be multiplexed in a CDM (Code Division Multiplexing) method on one resource element, respectively.

Abstract: A method of transmitting channel state information from a user equipment in a wireless communication system is disclosed. In order to report the channel state information, the user equipment is able to additionally transmit noise plus interference variance information as well as spatial channel matrix or spatial channel covariance matrix. The spatial channel matrix or spatial channel covariance matrix and the noise plus interference variance information can include information on a prescribed number of subbands in best channel states and can include information on a wideband including a plurality of subbands. Moreover, the user equipment is able to transmit normalized spatial channel matrix or spatial channel covariance matrix and normalized noise plus interference variance information for accurate and efficient transmission of the channel state information.