Parallel-Filtering Based Equalization of OFDM over Doubly Selective Channels

Time selectivity of multipath channels severely degrades the performance of OFDM systems. In this paper, a piece-wise channel approximation is presented for improving the structure of the frequency-domain channel gain matrix. The proposed model is exploited to simplify the zero-forcing (ZF) equalizer as a parallel-filtering implementation with very low complexity. The linearized case of the parallel-filtering based equalizer is studied and applied to the DVB-H receiver design. The simulation indicates that the developed equalizer enforces considerably the immunity of the DVB-H receiver to the time selectivity with very little complexity increased.

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