Effect of Feedback Delay on Multi-Antenna Limited Feedback for Temporally-Correlated Channels

A novel method based on Markov chain theory is proposed for analyzing the effect of feedback delay on a transmit beamforming system with limited feedback. Using this method, the ergodic capacity with delayed feedback of channel state information is derived. The capacity gain with respect to the case of no feedback is shown to decrease at least exponentially with the feedback delay. From theses results, useful design guidelines can be derived for choosing system parameters including the vehicular speed and the tolerable feedback delay.