MOBILE ASSISTED DOWNLINK BEAMFORMING WITH ANTENNA WEIGHT FEEDBACK

摘要

A subscriber unit (104) with multiple receive antennas (160, 162) and a single transmit antenna (160) derives beamforming weights to be used at a base station (102) with multiple transmitting antennas (602, 604, 606, and 608). The downlink beamforming weights are derived at the subscriber unit (104) from a prior downlink transmission from the base station (102) to the subscriber device (104) and an uplink sounding signal is used to carry derived downlink beam forming weights to the base station (102). Downlink antenna specific pilots (without weight) are used at the subscriber device (104) to determine the beamforming weights. Decimated sounding signals, where the number of sounding subcarriers is al least the same as the number of antennas at the base station (102), allow multiple users to sound at the same time.