Time-Selective channel estimation using pilot added scheme in OFDM systems

Time-selective channel estimator for orthogonal frequency division multiplexing (OFDM) systems using pilot added scheme is proposed in this paper. The OFDM system is with robustness to multipath fading in wireless communications. At the same time, time-variation can destroy the orthogonality between subcarriers which will degrade the performance of the system. In this paper, we propose a pilot added scheme which superimposes periodic pilot sequences on information bearing symbols. This approach is computationally simple and spectrally efficient as well. The results of computer simulations are presented and the factors which can affect the performance are analyzed.