Performance Bounds in OFDM Channel Prediction

OFDM channel prediction algorithms have been proposed to combat feedback delay in adaptive OFDM systems. However, no simple closed-form expression that relates prediction mean-square error (MSE) with the design parameters in OFDM channel prediction has been reported in the literature. This paper attempts to fill that gap by deriving simple closed- form asymptotic lower bounds of the MSE for OFDM channel prediction in deterministic doubly-selective fading channels. The bounds relate the best-achievable MSE with the predictor design parameters in a simple manner, thus providing important insight into the design of OFDM channel predictors. We compare the bounds to the deterministic Cramer-Rao bound for parameters consistent with IEEE 802.16e, and show that the asymptotic bounds are reasonably tight for practical scenarios.