Performance Analysis of Diagonal Precoding for Alamouti STBC over Nakagami-m Fading Channels

In this paper, we study the problem of one bit imperfect feedback based diagonal precoding for Alamouti spacetime block code in a 2 x 1 multiple-input single-output (MISO) communication system. The communication links are assumed to be Nakagami-m distributed. An accurate bit error rate (BER) expression of the considered MISO system is derived with erroneous feedback by using the order statistics. The average BER of the precoding scheme is minimized to find the optimized transmit weights. Further, we also derive the Shannon capacity of the scheme by using the moment generating function approach. Simulated and analytical results show that a significant capacity gain is achieved by the considered scheme as compared to the uniform power allocation over the Nakagami-m fading channels.