Abstract: Provided is a method and apparatus for efficiently measuring a load of a cell in a wireless communication system. The method includes dividing terminals in a cell into terminal groups that are different in resource allocation scheme, and calculating the number of wireless resources that the terminals effectively occupy based on the amount of required wireless resources for each terminal group; and measuring a load of the cell using the calculated number of wireless resources.

Abstract: A method and apparatus are provided for determining channel quality in a wireless communication system. The method includes receiving Channel Quality Information (CQI) from a receiver; generating a channel quality reference value by correcting the received CQI using first resource use/nonuse information received from a scheduler that indicates whether an adjacent cell used resources at a previous time, and received signal power information measured in the adjacent cell; and determining a channel quality value at a current time using the generated channel quality reference value and second resource use/nonuse information received from the scheduler that indicates whether an adjacent cell uses resources at the current time.

Abstract: In a Multiple-Input Multiple-Output (MIMO) communication system, a serving evolved Node B (eNB) receives a channel covariance matrix of the serving eNB and a channel covariance matrix for a first neighbor eNB with the highest interference among neighbor eNBs, from a User Equipment (UE). Received signal power information is generated for each subband-beam pair. Interference signal power information is generated for each subband-beam pair for the first neighbor eNB. The generated interference signal power information is exchanged with the first neighbor eNB for each subband-beam pair. Beam coordination information indicating a use status of each beam in each subband is generated for the UE, using the interference signal power information of the first neighbor eNB. The generated beam coordination information is exchanged with the neighbor eNB. Scheduling is performed on the UE using the generated beam coordination information and the beam coordination information of the first neighbor eNB.

Abstract: The present invention relates to a method and apparatus for transmitting data in a wireless communication system for supporting multi-cells formed of a plurality of sub-cells. The method includes the steps of: connecting at least one virtual transmission port to each of the plurality of sub-cells; determining the transmission mode for a terminal on the basis of channel states between at least two of the plurality of sub-cells and the terminal; and transmitting data for each sub-cell to the terminal through at least one virtual transmission port connected to a corresponding sub-cell on the basis of the determined transmission mode.

Abstract: A method of determining a serving sub-cell of a terminal among a plurality of sub-cells by a base station in a wireless communication system is provided. The method includes generating reference signal transmission interval information for each of the sub-cells by configuring a reference signal transmission interval for each of the plurality of sub-cells, and transmitting the reference signal transmission interval information for each of the sub-cells to the corresponding sub-cell, receiving channel status information for at least one sub-cell among the plurality of sub-cells from the terminal, and determining a serving sub-cell of the terminal by using at least one of the reference signal transmission interval information, the channel status information, a reception time of the channel status information, of each of the sub-cells.

Abstract: A method and apparatus are provided for determining channel quality in a wireless communication system. The method includes receiving Channel Quality Information (CQI) from a receiver; generating a channel quality reference value by correcting the received CQI using first resource use/nonuse information received from a scheduler that indicates whether an adjacent cell used resources at a previous time, and received signal power information measured in the adjacent cell; and determining a channel quality value at a current time using the generated channel quality reference value and second resource use/nonuse information received from the scheduler that indicates whether an adjacent cell uses resources at the current time.

Abstract: A Mobile Station (MS) is operable to select a precoding matrix in a multi-antenna wireless communication system. The method includes receiving, from a serving Base Station (BS), information on a precoding matrix of which use is prohibited and a precoding matrix to be used by a neighbor BS, estimating an interference signal for the precoding matrix to be used by the neighbor BS, and selecting a precoding matrix to be used by the serving BS by considering the estimated interference signal from the remaining precoding matrixes except for the precoding matrix of which use is prohibited among precoding matrixes used by the serving BS.

Abstract: Methods and apparatus are provided for controlling interference by a TP in a wireless communication system. A first message, which includes channel quality information for the TP, is received from a terminal to which the TP provides a communication service. A second message, which includes received power information for a reference signal received from the terminal, is received from at least one neighbor TP. A data transmission rate is determined for the terminal based on the channel quality information and the received power information.

Abstract: Methods, an apparatus, and a network manager for cooperative communication are provided. A method of communication by a serving base station performing a cooperative communication with a plurality of base stations includes selecting serving channel code information based on Channel Status Information (CSI) of the serving base station, receiving cooperating channel code information based on CSI of a cooperating base station from the cooperating base station performing the cooperative communication with the serving base station, determining a compensation parameter based on the serving channel code information and the cooperating channel code information, and determining a beamforming vector of the serving base station based on the compensation parameter.

Abstract: An apparatus and method for resource allocation information transmission is provided. The method includes determining a search space for use in a second frequency band using resource allocation information of a first process detected in a first frequency band, detecting resource allocation information using the search space in the second frequency band, and when failing to decode received data according to the resource allocation information detected in the second frequency band, re-detecting resource allocation information of the first process in the second frequency band in a first time interval using the search space without detecting the resource allocation information of the first process in the first frequency band.

Abstract: A communication system to feed back an index of a precoding matrix is provided. A terminal may feed back an index of an optimal precoding matrix based on estimated channel status. A base station may transmit data to the terminal based on the index of the precoding matrix received from the terminal.

Abstract: In the communications system of the present invention, a communications terminal determines a precoding matrix index in a pilot signal received through a specific downlink channel, examines channel quality information of the downlink channel according to the determined precoding matrix index, and transmits feedback information to a serving base station, which determines a priority factor by using the examined channel quality information, and compares the priority factor with other priority factors. The comparison is used such that a base station having a high priority suggests the use of the precoding matrix to the neighboring base station.

Abstract: The present invention relates to a system and to a method for the cooperation among base stations, in which a communication service is provided to a plurality of communication terminals through the plurality of base stations. When channel state information of a communication terminal is acquired, a serving base station selects a serving channel code matching the channel state information from a codebook, calculates linear transform information using the serving channel code and the channel state information, and transmits the serving channel code to a cooperative base station. When the cooperative base station receives a cooperation channel code, the serving base station calculates serving weight information of the serving base station and cooperation weight information of the cooperative base station using the serving channel code and the cooperation channel code, and determines a beam forming vector by applying the linear transform information to the serving weight information.

Abstract: An apparatus and method for resource allocation information transmission is provided. The method includes determining a search space for use in a second frequency band using resource allocation information of a first process detected in a first frequency band, detecting resource allocation information using the search space in the second frequency band, and when failing to decode received data according to the resource allocation information detected in the second frequency band, re-detecting resource allocation information of the first process in the second frequency band in a first time interval using the search space without detecting the resource allocation information of the first process in the first frequency band.

Abstract: A transmission method and apparatus are provided for use in a wireless communication system in which a cell includes a plurality of sub-cells. A Transmission Point (TP) in the wireless communication system includes a transmitter configured to transmit a signal to each of the plurality of sub-cells through a plurality of antennas; a receiver configured to receive uplink control information from a User Equipment (UE) located within at least one of the plurality of sub-cells; and a controller configured to determine a virtual matrix for each of the plurality of sub-cells, to select a precoding matrix according to the virtual matrices of the plurality of sub-cells, to determine a cooperative transmission mode or a normal transmission mode, based on the received uplink control information, and to control the transmitter to perform downlink transmission on a sub-cell basis through the virtual matrices of the sub-cells according to the determined transmission mode.

Abstract: An apparatus and method for detecting signals based on a Lattice Reduction (LR) algorithm in a Multiple Input Multiple Output (MIMO) wireless communication system are provided.

Abstract: A method for operating a Mobile Station (MS) in a Multiple Input Multiple Output (MIMO) wireless communication system is provided. The method includes measuring channel quality for a serving Base Station (BS), if the channel quality is less than a threshold, measuring interference power from one or more neighbor BSs, determining a Precoding Matrix Index (PMI) and a priority metric for each neighbor BS, and feeding back at least one of the PMI, a PMI type indicator, the priority metric, and the channel quality to the serving BS.

Abstract: An apparatus and method for reducing pilot overhead in a multi-antenna system are provided. The method generates postcodes and pre-codes for streams used to transmit signals to at least two receivers. The method allocates a pilot signal to at least one of the streams, and allocates an additional pilot signal shared by at least one of the streams. The method precodes the pilot signal allocated to at least one of the streams, the additional pilot signal, and data to be transmitted to each of the receivers, based on the pre-code for each of the streams, prior to transmission.

Abstract: A method and apparatus for multi-cell calibration in a wireless communication system supporting cooperative Multiple Input Multiple Output (MIMO) are provided. Operations of a Base Station (BS) according to the method include transmitting a first message indicating a start of multi-cell sounding calibration to a reference Mobile Station (MS); estimating an uplink channel matrix of the reference MS using pilot symbols received from the reference MS; transmitting pilot symbols for enabling the reference MS to estimate a downlink channel matrix; when receiving downlink channel information of cooperative BSs from the reference MS, transmitting second messages comprising the downlink channel information to the cooperative BSs; and determining a multi-cell calibration matrix using the uplink channel matrix and the downlink channel information received from the reference MS.

Abstract: An apparatus and a method for beamforming in a wireless communication using a Base Station (BS) cooperative scheme are provided. The beamforming method includes exchanging channel status information with at least one cooperative BS which provides a BS cooperative service, generating a beamforming weight based on the channel status information, determining channel variation caused by a time delay in the channel status information exchange with the cooperative BS, updating the generated beamforming weight based on the channel variation, and precoding a transmit signal based on the updated beamforming weight.