A simple downlink diversity transmit scheme for cooperative base stations

In this paper, a simple downlink transmit scheme joint beamforming (BF) with space-time block coding (STBC) is proposed for cooperative base stations (BS). By deriving the equivalent signal-to-noise ratio (SNR) at the receiver, we first obtain the optimal BF weight vectors and the allocated power coefficients in terms of maximizing the statistical mutual information. Then, based on the moment generation function (MGF) approach and Gauss-Chebyshev numerical quadrature, we present a method to evaluate the average symbol error rate (SER) of the system with the new scheme. Finally, computer simulation results demonstrate the validity of the performance analysis and the superiority of the proposed transmit scheme.