Beamforming in Correlated MISO Systems with Channel Estimation Error and Feedback Delay

This paper analyzes the exact average symbol error rate (SER) performance of beamforming in spatially correlated multiple-input single output (MISO) systems with channel estimation error and feedback delay. We derive the joint distribution function of two quadratic forms and employ the result to obtain an expression for the cumulative distribution function (cdf) of the received signal-to-noise ratio (SNR). Using this cdf expression, we investigate the exact SER applicable for a large number of modulation schemes. The results show that the average SER performance is sensitive to feedback delay, channel estimation and spatial correlation at the transmitter. Furthermore, feedback delay causes an error floor and has the most degrading impact on performance. We also present Monte Carlo simulation results as verification of our analytical results.