Alamouti transmit diversity scheme with a simple diagonal weighting matrix

In this paper, a novel scenario of the Alamouti´s space-time block code (STBC) system combined with a simple diagonal weighting matrix is presented. The diagonal weighting matrix is performed at the transmitter, dependent on the channel state information (CSI) which is obtained by using a feedback link. The signal can be decoded by updating the channel gain which was changed due to the weighting effect at each of two transmitters based on feedback information. The BER performance analysis about the decoded signal using the above scheme was derived theoretically and was shown to be better 1.3 dB than the Alamouti´s STBC transmit diversity with open loop scheme