Low complexity iterative method of signal detection in OFDM doubly selective channels

Time selectivity of the channel causes inter-carrier interference (ICI) in orthogonal frequency division multiplexing (OFDM), thereby degrading the system performance significantly and increasing the computational complexity of the receiver. On the other hand, time selectivity introduces temporal diversity that can be exploited to improve the performance of the receiver. In this work, a new method is presented to compensate for the effects of time selectivity of the channel that exploits the sparsity present in the channel convolution matrix (CCM). Here, working with time and frequency domain samples, a low complexity iterative algorithm is proposed. Simulation results show the superior performance over the standard linear minimum mean square error (L-MMSE) equalizer with the advantage of computational saving and temporal diversity gain.