Least-squares Beamforming in Wireless Networks

Friday, August 10, 2001 - 11:30am - 12:30pm
Keller 3-180
Mitch Trott (ArrayComm)
Beamforming methods based on linear least squares have been widely proposed for use with wireless systems employing multiple antennas. Such methods have been suggested for both reception and transmission. We survey the existing research in this area, focusing particularly on the interaction of power control, receive beamforming, and transmit beamforming in cellular networks. We show that transmit beamforming based on least-squares receive processing can have surprising behavior in a network.

In practical systems least-squares solutions are based on limited training data. Are the basic characteristics of beamformers based on perfect training (i.e., MMSE beamformers) preserved in the face of finite training data? We use results developed the 1970s for maximum likelihood spectral estimation to provide a partial answer to this question for transmit beamforming.