Abstract: A method of efficiently transmitting CoMP feedback information from an user equipment, which performs CoMP operation, in a wireless communication system to reduce inter-cell interference is disclosed. The user equipment requests a neighboring cell, which affects the user equipment through interference, to restrict use of a specific beam pattern group in a serving cell direction. In this case, whether the user equipment will request such restriction is determined based on a channel status value of the user equipment. If the user equipment determines to request such restriction, the user equipment transmits a request message to a serving base station, the request message requesting to restrict use of the specific beam pattern group. In this case, the user equipment performs scheduling and requests a specific neighboring cell to restrict use of the specific beam pattern group at a specific resource region.

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: A method of transmitting data in a wireless communication system includes preparing a frame including a unicast subframe for unicast data and an MBS (Multicast and Broadcast Service) subframe for MBS data; and transmitting the unicast data and the MBS data via the frame, wherein the MBS subframe includes an idle time during which data is not carried, and the idle time is arranged to be at the temporally latest position in the MBS subframe. An MBS frame structure for using an appropriate CP with respect to MBS signals transmitted from multi-cell is provided, so an unnecessary idle time can be reduced, and thus, the efficiency of limited radio resources can be improved.

Abstract: A method for allocating fractional frequency reuse (FER) resources to perform cooperative MIMO in a multi-cell environment is disclosed. A cell which requests FER resources decides a band for cooperative MIMO with its neighboring cell, and requests the neighboring cell to allocate the decided band for cooperative MIMO. A cell which receives FER resource request receives a request from a neighboring cell to allocate some or all of FER bands allocated to the neighboring cell as a band for cooperative MIMO, decides whether to grant the request, and allocates some or all of the requested FER bands as the band for cooperative MIMO with the neighboring cell if the request is granted.

Abstract: A PMI combination ratio (PCR) being used for generating a uplink precoding matrix W is transmitted by a base station to a mobile station. Using the PCR, a PMI maximizing transmission performance and PMIMin minimizing interference to a neighboring base station are combined into the uplink precoding matrix W. Overall operations of a system can be simplified and the load of calculation for generating the uplink precoding matrix W in the mobile station can be reduced, because the PCR is provided by the base station.

Abstract: The present invention relates to a method for synchronizing multiple cells, which perform cooperative multi-input multi-output operations, as well as to a method for inter-cell synchronization in a multi-cell environment, comprising the steps of: measuring a propagation delay of a cooperative base station; transmitting the measured propagation delay to a serving base station; and receiving data for cooperative multi-input multi-output operations in which a transmission location is adjusted, on the basis of the propagation delay of the cooperative base station, when the serving base station transmits the propagation delay to the cooperative base station.

Abstract: The present invention provides feedback control information for the multiple base stations multiple input multiple output (MIMO). The feedback control information according to the present invention includes a target resource unit (TRU) indicating a frequency resource unit to be measured for a feedback. A mobile station according to the present invention transmits feedback information worked on the latest best subbands reported for single base station MIMO.

Abstract: A method and an apparatus for transmitting a reference signal in a multiple antenna system are provided. The method includes transmitting a common reference signal through N antennas (N<M, where M and N is a natural number), and transmitting a dedicated reference signal through M?N antennas, wherein the common reference signal is transmitted to all user equipments within a cell, and the dedicated reference signal is transmitted to at least one user equipment within the cell.

Abstract: A method of transmitting data in a multiple antenna system, including: transmitting a channel estimation signal including a first pilot for channel estimation of a first UE supporting multiple antennas and a second pilot for channel estimation of a second UE supporting a larger number of multiple antennas than that of the first UE; and receiving feedback data in response to the channel estimation signal.

Abstract: A method of performing a feedback for a multicast and broadcast service (MBS) is disclosed. A Multicast Broadcast Service (MBS) feedback method includes, generating, by a base station contained in a multi-cell multicast broadcast single frequency network (MBSFN) zone, a ranging channel code for a multicast broadcast service (MBS) feedback, allocating the ranging channel code to a mobile station contained in a cell zone of the base station, and receiving the MBS feedback information based on the ranging channel code from the mobile station. So, an adaptive modulation and coding (AMC) is applied to the MBS according to the NACK feedback, such that a throughput of the MBS system increases.

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: A method for performing a Coordinated Multi-Point (CoMP) operation and transmitting feedback information in a wireless communication system is disclosed. The method includes measuring interference levels or noise and interference variances of reference signals received from one or more neighbor cells, and transmitting to a serving Base Station (BS) information about the measured interference levels or noise and interference variances, and information about a Precoding Matrix Index (PMI) that a mobile station (MS) wants to restrict or recommend for a neighbor cell performing the CoMP operation.

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: The present invention relates to a method and an apparatus for information transmission in a radio communication system. The method includes the steps of creating a first symbol and a second symbol relevant to information, creating a first transmission vector and a second transmission vector on the basis of Alamouti code from the first symbol and the second symbol, and transmitting the first transmission vector via a first antenna and transmitting the second transmission vector via a second antenna.

Abstract: A method of transmitting and receiving feedback information in a multi-cell based wireless communication system using FFR, a mobile station apparatus therefore and a base station apparatus therefore are disclosed. A mobile station is able to obtain FFR configuration information including configuration information on at least one frequency partition to which a corresponding FFR is applied per cell ID. And, the mobile station is able to transmit PMI information to a serving base station using the obtained FFR configuration information. In this case, the PMI information is specifically restricted or recommended by the mobile station among PMIs (precoding matrix indexes) used by at least one neighbor cell in an allocated specific frequency partition.

Abstract: A method and apparatus for transmitting a Precoding Matrix Index (PMI) in a Coordinated Multi-Point (CoMP) communication system are disclosed. The method includes receiving signals in a same frequency band from Base Stations (BSs) included in a CoMP set, which operate in joint processing mode, selecting a first precoding matrix for each of the BSs using the received signals, generating a second precoding matrix by combining the first precoding matrices, and transmitting an index of the second precoding matrix to a serving BS among the BSs.

Abstract: A method of transmitting an acknowledgment (ACK)/non-acknowledgement (NACK) signal in a wireless communication system includes assigning at least one ACK channel among a plurality of ACK channels which share an ACK channel region for transmitting the ACK/NACK signal, and transmitting the ACK/NACK signal through the at least one ACK channel, wherein the ACK channel region includes at least one tile including a plurality of data subcarriers, and the ACK/NACK signal of each ACK channel is indicated by mapping different orthogonal vectors respectively to the plurality of ACK channels in the tile.

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: 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: 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.