Considering the serious Inter-Carrier Interference (ICI) in Orthogonal Frequency Division Multiplexing (OFDM) wireless systems with high frequency

a low complexity frequency-domain linear equalization algorithm based on pre-processing is proposed.The new algorithm first extracts a time-variant factor from every channel response.Consequently

one-dimensional filtering pre-processing in time-domain can be achieved at the receiver.As for the time-variant channel after time-variant factor extraction

Banded structure is used to approximate its frequency response matrix

which achieves low complexity frequency-domain linear equalization at the receiver.The analysis and simulation results show that

the proposed algorithm can reduce the complexity to 10% or less at the cost of 1-2dB performance

relative to MMSE algorithm;the proposed algorithm can obtain at least 5dB relative performance gain with the same complexity

compared to the existing low complexity algorithm which discards part channel information.