Adaptive Beamforming in Interference Networks via Bi-Directional Training

Date Added: Mar 2010
Format: PDF

The authors study distributed algorithms for adjusting beam-forming vectors and receiver filters in Multiple-Input Multiple-Output (MIMO) interference networks, with the assumption that each user uses a single beam and a linear filter at the receiver. In such a setting there have been several distributed algorithms studied for maximizing the sum-rate or sum-utility assuming perfect Channel State Information (CSI) at the transmitters and receivers. The focus of this paper is to study adaptive algorithms for time-varying channels, without assuming any CSI at the transmitters or receivers. Specifically, they consider an adaptive version of the recent Max-SINR algorithm for a time-division duplex system. This algorithm uses a period of bi-directional training followed by a block of data transmission.