Performance of a base station feedback-type adaptive array antenna with limited feedback bits

The feedback-type adaptive array antenna has been proposed for frequency division duplexed (FDD) systems, where the mobile station (MS) measures channel characteristics and feeds them back to the base station. Using a number of feed-back bits provides better performance but it wastes channel capacity of the up-link. To solve this problem, this paper proposes a method in which the MS sends back the difference between weights which are currently used and the optimum weights calculated at the MS. Bit error rate performance of the system is shown under realistic propagation conditions.