Multi-antenna transmission method and system

A system for transmitting a transmission signal from an antenna array to a unit configured to receive of a wireless communication system, said system comprising:

• a) a unit configured to measure a signal quality at said unit configured to receive for predetermined antennas or beams of said antenna array;
• b) a unit configured to select at least two of said predetermined antennas or beams of said antenna array based on feedback information derived from said signal quality measurement;
• and
• c) a unit configured to transmit said transmission signal using said at least two selected antennas or beams according to a transmit diversity or beamforming scheme;
• wherein said unit configured to select comprises a pre-selection unit arranged at said unit configured to receive and a final selection unit arranged at a transmitting end;
• wherein said final selection unit is arranged to perform selection based on a scoring system which takes into account said feedback information, an amplifier load condition of channels associated with said at least two selected antennas, and a degree of interference to co-channel users of said associated channels;
• wherein the scoring system is implemented by defining final scores of said at least two selected antennas, the final scores being defined by scores for respective antennas of said at least two selected antennas, the scores for the respective antennas including a score of a respective antenna due to a selection by the unit configured to receive, the score of a power loading of a power amplifier of the respective antenna, the score of interference produced by the respective antenna and the score of a selection of the respective antenna in former transmission bursts;
• and
• the system being configured to weight the scores and to sum up the weighted scores so as to form a final score for the respective antenna.

A base station for transmitting a transmission signal from an antenna array to a unit configured to receive of a wireless communication system, comprising:

• a) a unit configured to select at least two predetermined antennas or beams of said antenna array based on feedback information derived from a signal quality measurement;
• and
• b) a unit configured to transmit said transmission signal using said at least two selected antennas or beams according to a transmit diversity or beamforming scheme;
• wherein said unit configured to select comprises a final selection unit arranged at the base station;
• wherein said final selection unit is arranged to perform selection based on a scoring system which takes into account said feedback information, an amplifier load condition of channels associated with said at least two selected antennas, and a degree of interference to co-channel users of said associated channels;
• wherein the scoring system is implemented by defining final scores of said at least two selected antennas, the final scores being defined by scores for respective antennas of said at least two selected antennas, the scores for the respective antennas including a score of a respective antenna due to a selection by the unit configured to receive, the score of a power loading of a power amplifier of the respective antenna, the score of interference produced by the respective antenna and the score of a selection of the respective antenna in former transmission bursts;
• and
• the base station being configured to weight the scores and to sum up the weighted scores so as to form a final score for the respective antenna.