A new fast sub-optimal search method for closed-loop transmit diversity system with limited number of feedback bits

We present a fast sub-optimal searching algorithm for the closed-loop transmit diversity scheme used in wireless systems. Under the low mobility condition and with perfect channel knowledge at the receiving end, our proposed searching algorithm can use a limited number of feedback bits to provide a sub-optimal solution that can achieve SNR values close to the optimal solution with a greatly reduced complexity and outperform other sub-optimal schemes. The scheme also works well under the presence of feedback errors.