Abstract: A multiple input multiple output (MIMO) communication system using a first codebook and a second codebook is provided. The first codebook and the second codebook may independently exist, or may exist in a form of an overall codebook in which the first codebook and the second codebook are integrated with each other. A receiver may extract a first precoding matrix indicator from the first codebook, and may extract a second precoding matrix indicator from the second codebook. The receiver may also extract the first precoding matrix indicator and the second precoding matrix indicator from the overall codebook. The first precoding matrix indicator and the second precoding matrix indicator may be fed back to a transmitter. The transmitter may determine a precoding matrix based on the first precoding matrix indicator and the second precoding matrix indicator.

Abstract: A communication system control method, a communication system control apparatus and an apparatus for use in a communication system are provided. The communication system control apparatus includes an information collection unit to collect user set information about candidate user sets grouped by a plurality of base stations, and a scheduler to select target user sets corresponding to the plurality of base stations from among the candidate user sets based on an achievable sum data transmission rate of the plurality of base stations, and perform scheduling with respect to users included in the target user sets, the achievable sum data transmission rate being calculated based on the user set information.

Abstract: Disclosed are a Multiple User Multiple Input Multiple Output (MU-MIMO) codebook design method, and a communication device using the codebook. A MU-MIMO codebook design method includes analyzing beam patterns of candidate vectors included in a predetermined candidate codebook, and eliminating at least one of the candidate vectors based on the beam patterns of the candidate vectors to generate the MU-MIMO codebook for a MU-MIMO system being comprised of the remaining vectors.

Abstract: Provided are a base station configured to provide an interference vector indicator to a terminal, and the terminal configured to recognize at least one remaining precoding vector using the interference vector indicator. Each of the base station and the terminal may configure a mapping table between at least one bit for the interference vector indicator indicating the at least one remaining precoding vector, and a plurality of vectors included in a codebook, based on a probability that the plurality of vectors may be included in a precoding matrix. In this instance, the base station may generate the interference vector indicator using the mapping table, and the terminal may recognize the at least one remaining precoding vector using the mapping table. The mapping table may be differently configured according to various modes.

Abstract: A Multiple-Input Multiple-Output (MIMO) communication method and system, the MIMO communication system including: a first channel quality information (CQI) receiving unit to receive first CQI from a user terminal, the first CQI associated with a beamforming vector selected by the user terminal; and a second CQI generating unit to generate second CQI by correcting the first CQI based on a transmission rank associated with a number of data streams to be transmitted.

Abstract: Disclosed are a Multiple User Multiple Input Multiple Output (MU-MIMO) codebook design method, and a communication device using the codebook. A MU-MIMO codebook design method includes analyzing beam patterns of candidate vectors included in a predetermined candidate codebook, and eliminating at least one of the candidate vectors based on the beam patterns of the candidate vectors to generate the MU-MIMO codebook for a MU-MIMO system being comprised of the remaining vectors.

Abstract: A communication device using user cooperation is provided with a channel information reception unit to receive channel information from a plurality of member terminals within the same group, the channel information being associated with a radio channel formed between the plurality of member terminals and a base station; a member terminal selection unit to select at least one active member terminal from among the plurality of member terminals based on the channel information; and a selection information transmission unit to transmit selection information to the base station, the selection information being associated with a radio channel formed between the at least one active member terminal and the base station.

Abstract: A multiple input multiple output (MIMO) communication system using a first codebook and a second codebook is provided. The first codebook and the second codebook may independently exist, or may exist in a form of an overall codebook in which the first codebook and the second codebook are integrated with each other. A receiver may extract a first precoding matrix indicator from the first codebook, and may extract a second precoding matrix indicator from the second codebook. The receiver may also extract the first precoding matrix indicator and the second precoding matrix indicator from the overall codebook. The first precoding matrix indicator and the second precoding matrix indicator may be fed back to a transmitter. The transmitter may determine a precoding matrix based on the first precoding matrix indicator and the second precoding matrix indicator.

Abstract: Disclosed are a Multiple User Multiple Input Multiple Output (MU-MIMO) codebook design method, and a communication device using the codebook. A MU-MIMO codebook design method includes analyzing beam patterns of candidate vectors included in a predetermined candidate codebook, and eliminating at least one of the candidate vectors based on the beam patterns of the candidate vectors to generate the MU-MIMO codebook for a MU-MIMO system being comprised of the remaining vectors.

Abstract: A communication device using user cooperation is provided with a channel information reception unit to receive channel information from a plurality of member terminals within the same group, the channel information being associated with a radio channel formed between the plurality of member terminals and a base station; a member terminal selection unit to select at least one active member terminal from among the plurality of member terminals based on the channel information; and a selection information transmission unit to transmit selection information to the base station, the selection information being associated with a radio channel formed between the at least one active member terminal and the base station.

Abstract: Provided are a base station configured to provide an interference vector indicator to a terminal, and the terminal configured to recognize at least one remaining precoding vector using the interference vector indicator. Each of the base station and the terminal may configure a mapping table between at least one bit for the interference vector indicator indicating the at least one remaining precoding vector, and a plurality of vectors included in a codebook, based on a probability that the plurality of vectors may be included in a precoding matrix. In this instance, the base station may generate the interference vector indicator using the mapping table, and the terminal may recognize the at least one remaining precoding vector using the mapping table. The mapping table may be differently configured according to various modes.

Abstract: A communication system control method, a communication system control apparatus and an apparatus for use in a communication system are provided. The communication system control apparatus includes an information collection unit to collect user set information about candidate user sets grouped by a plurality of base stations, and a scheduler to select target user sets corresponding to the plurality of base stations from among the candidate user sets based on an achievable sum data transmission rate of the plurality of base stations, and perform scheduling with respect to users included in the target user sets, the achievable sum data transmission rate being calculated based on the user set information.

Abstract: Disclosed are a Multiple User Multiple Input Multiple Output (MU-MIMO) codebook design method, and a communication device using the codebook. A MU-MIMO codebook design method includes analyzing beam patterns of candidate vectors included in a predetermined candidate codebook, and eliminating at least one of the candidate vectors based on the beam patterns of the candidate vectors to generate the MU-MIMO codebook for a MU-MIMO system being comprised of the remaining vectors.

Abstract: A communication device using user cooperation is provided with a channel information reception unit to receive channel information from a plurality of member terminals within the same group, the channel information being associated with a radio channel formed between the plurality of member terminals and a base station; a member terminal selection unit to select at least one active member terminal from among the plurality of member terminals based on the channel information; and a selection information transmission unit to transmit selection information to the base station, the selection information being associated with a radio channel formed between the at least one active member terminal and the base station.

Abstract: A Multiple-Input Multiple-Output (MIMO) communication method and system, the MIMO communication system including: a first channel quality information (CQI) receiving unit to receive first CQI from a user terminal, the first CQI associated with a beamforming vector selected by the user terminal; and a second CQI generating unit to generate second CQI by correcting the first CQI based on a transmission rank associated with a number of data streams to be transmitted.