Performance evaluation of limited feedback transmit precoding via phase rotation in correlated MIMO channel

This paper proposes a phase rotation (PR) method as a limited feedback transmit precoding for correlated multiple input multiple-output (MIMO) channel. In the conventional PR precoding, the phase angle is obtained from a channel correlation matrix to reduce the influence of spatial correlation. We propose a PR precoding using instantaneous channel state information (CSI), which has a potential to achieve more reliable communication but requires more frequent CSI feedbacks compared to the conventional method. To reduce the feedback cost, a quantization of feedback information is employed. By the computer simulations, we showed that the suitable quantization size depends on the modulation type . We also showed the symbol error rate performance in terms of the Doppler shift since the conventional method has more robustness against the Doppler shift. The simulation results showed that the proposed PR method outperforms the conventional method in the slow fading environment.