Open-loop beamforming MIMO communications in frequency division duplex systems

An apparatus comprising:

• a plurality of antennas;
• a receiver that is configured to process signals received at the plurality of antennas, which signals were transmitted in a first frequency band by another communication apparatus;
• a controller coupled to the receiver, wherein the controller is configured to:
• compute a set of candidate beamforming weight vectors using each of the plurality of methods to produce a plurality of sets of candidate beamforming weight vectors without feedback information from the other communication apparatus about a wireless link from the plurality of antennas to the other communication apparatus;
• compute a correlation rate and predicted average beamforming performance among candidate beamforming weight vectors within each set;
• and
• select one of the plurality of sets of candidate beamforming weight vectors based on a degree of correlation and predicted average beamforming performance among its candidate beamforming weight vectors;
• and
• a transmitter coupled to the controller, wherein the transmitter is configured to apply the selected one of the plurality of sets of candidate beamforming weight vectors to multiple signal streams to beamform multiple signal streams for transmission in a second frequency band via the plurality of antennas to the other communication apparatus.

One or more tangible processor readable storage media storing instructions for execution by a processor and when executed operable to:

• compute a set of candidate beamforming weight vectors using each of the plurality of methods to produce a plurality of sets of candidate beamforming weight vectors without feedback information from the second device about a wireless link from the first device to the second device;
• compute a correlation rate and predicted average beamforming performance among candidate beamforming weight vectors within each set;
• and
• select one of the plurality of sets of candidate beamforming weight vectors based on a degree of correlation and predicted average beamforming performance among its candidate beamforming weight vectors;
• and
• apply the selected one of the plurality of sets of candidate beamforming weight vectors to multiple signal streams to beamform the multiple signal streams for transmission to the second device in a second frequency band.