DOWNLINK BEAMFORMING FOR SPATIALLY DISTRIBUTED SOURCES IN CELLULAR MOBILE COMMUNICATIONS

This paper presents a new technique for downlink transmission beamform er design in cellular mobile communication systems using antenna array s at the base station. The method is based on estimation of an underly ing spatial distribution associated with each source's spatial downlin k channel. The algorithm is 'blind' in the sense that it depends only on uplink spatial channel statistics, requiring no mobile-to-base stat ion feedback in the design procedure. The assumed underlying spatial d istribution models are general enough to be used in a wide variety of mobile communications scenarios (e.g., rural, urban, sub-urban, indoor ). The technique is of reasonable complexity with a significant portio n of the computation carried out off-line. Simulation results verify t he effectiveness of the approach. (C) 1998 Elsevier Science B.V. All r ights reserved.