OFDM Signal Detection in Doubly Selective Channels with Blockwise Whitening of Residual Intercarrier Interference and Noise
Orthogonal Frequency-Division Multiplexing (OFDM) is a popular broadband wireless transmission technique, but its performance can suffer severely from the Inter-Carrier Interference (ICI) induced by fast channel variation arising from high-speed motion. Existing ICI countermeasures usually address a few dominant ICI terms only and treat the residual similar to white noise. The authors show that the residual ICI has high normalized autocorrelation and that this normalized autocorrelation is insensitive to the multipath channel profile as well as a variety of other system and channel conditions. Consequently, the residual ICI plus noise can be whitened in a nearly channel-independent manner, leading to significantly improved detection performance. Simulation results confirm the theoretical analysis.