A novel iterative symbol detection of OFDM systems in time and frequency selective channels

When orthogonal frequency division multiplexing (OFDM) technology is applied in time- and frequency-selective, or doubly selective channels, the time-variant character of the channel destroys subcarrier orthogonality, resulting in inter-carrier interference (ICI). In general, the classical OFDM detection algorithms are neither effective to mitigate the ICI due to the high error floor in BER curves, nor applicable to the practice due to the high computational complexity encountered in the large-sized matrix inversion. To resolve this problem, an iterative symbol detection scheme, combined with linear preprocessing at the receiver to restrict ICI support and band approximation of the channel matrix is proposed. The simulation results demonstrate that the proposed algorithm achieves enhanced performances with lower complexities compared to the classical methods.