ICI Cancellation and Equalization for OFDM over Doubly-Selective Channel

In orthogonal frequency division multiplexing (OFDM) systems, Doppler effect introduced by high mobility leads to the loss of subcarrier orthogonality and the occurrence of inter-carrier interference(ICI). In order to eliminate ICI, by exploiting the ICI distribution and banded matrix property, a novel low complexity iterative interference cancellation algorithm and minimum-mean-squared error with ordering successive interference cancellation (MMSEOSIC) algorithm are proposed. Compared with the traditional ICI one-tap frequency domain equalization algorithm, simulation results show that the new schemes obtain the tradeoff between computational complexity and performance. The proposed MMSE-OSIC could effectively eliminate “error floor” by using the time diversity of time-varying channel in high SNR environments.