Average SEP Loss Analysis of Transmit Beamforming for Finite Rate Feedback MISO Systems with QAM Constellation

In this paper, utilizing high resolution quantization theory, we analyze the loss in average symbol error probability (SEP) for finite rate feedback MISO systems with rectangular M-QAM constellation. Assuming perfect channel estimation, no-feedback delay and error-less feedback, for spatially i.i.d and correlated channels we derive analytical expressions for loss in average SEP due to finite-rate channel quantization. We then consider the high-SNR regime and show that the loss associated with correlated case is related to the loss associated with the i.i.d case by a scaling constant given by the determinant of the correlation matrix. We also present simulation results in support of the analytical expressions.