Abstract

In this paper, we compare two methods of subspace blind channel estimation in orthogonal frequency division multiplexing (OFDM) systems using different guard intervals under multi-path channel with exponentially decaying power profile. Single pilot signal is used in both models to solve the scalar ambiguity problem which is a common problem in all subspace approaches. The bit error rate (BER) and the normalized mean square error (NMSE) of the systems were compared under various signal to noise ratio (SNR) and different number of transmitted OFDM symbols , as well as the impact of the position of pilot signal. The results of channel estimation, data detection and system complexity show that the zero padding (ZP) model superior the model with cyclic prefix (CP).