Low-complexity OFDM channel predictor design with varying speed receivers in time-varying wireless channels

Signals transmitted through a wireless channel undergo distortion due to multi-path and Doppler shift effects which can be recovered at the receiver through channel state information (CSI). The variation of wireless channels causes outdated CSI to be used for optimization techniques. Channel prediction allows the system to adapt modulation methods to an estimated future CSI. But this becomes complex when the receiver moves with a varying speed since it directly affects the channel parameters. This paper proposes a channel prediction scheme in OFDM systems with speed-varying receivers. The predictor first tracks such speed variations and if significant change occurs, then the channel parameters are re-calculated and updated for future channel prediction. The theoretical arguments and simulations show that the proposed system can obtain good performance in multi-path channel conditions with low computational complexity.