Joint beamforming with space-time block coding for multi-antenna communications

A downlink transmit scheme joint beamforming (BF) with space-time block coding (STBC) is presented for multi-antenna communications. The proposed scheme first uses the equivalent scaled additive white Gaussian noise (AWGN) channel induced by STBC to yield the closed-form expression of the signal-to-noise ratio (SNR) at the receiver. Then based on the symbol error rate (SER) upper bound as design criterion, an optimal beamformer is developed, which is turned out to be an eigen-beamformer with proper power allocation among the multiple beams. Finally, some representative computer simulation results demonstrate that the proposed transmit scheme outperforms not only the conventional STBC, but also the other existing related strategies.