A simple algorithm for closed-loop transmit diversity with a low-data-rate feedback channel

We propose a simple algorithm called local search for controlling antenna weights in a closed-loop transmit diversity system. We show that when the bandwidth of the control feedback channel is limited, more antennas should be installed in the transmitter in spite of the reduction in number of bits for each antenna. We show by simulation that using one bit for each antenna maximizes the overall SNR. Furthermore, our proposed algorithm can outperform an existing one by more than 20% in terms of SNR in some situations.