Performance analysis of adaptive low rate differential CSI feedback for MIMO-OFDM systems

In situations where the channels are fast changing, systems that require channel state information at the transmitter would need frequent feedback from the receiver. Low rate feedback will be required in these cases, and there have been many proposals on how to compress channel state information to enable a fast feedback to the transmitter. Of these proposed methods, a simple but yet promising way to achieve low rate feedback would be via the use of differential quantization techniques. In this paper, we investigate the use of adaptive delta modulation with givens rotation to encode the CSI in MIMO-OFDM systems. We look at the design of the feedback system, and investigate methods of improving the performance of such systems.