A novel Doppler shift estimation algorithm for OFDM-based transform domain communication systems

In this paper, we investigate the impact of Doppler shift on bit error rate (BER) in OFDM-based transform domain communication system (TDCS) and propose a novel Doppler shift estimation algorithm to recover the system performance. The Doppler shift estimation algorithm in OFDM systems is robustly designed and can be applied in OFDM-based TDCS. However, the accuracy of these existing estimation algorithms will degrade seriously when the signal to noise ratio (SNR) is low. An attractive feature of the proposed algorithm is that it can utilize characteristics of OFDM-based TDCS to estimate Doppler shift accurately with SNR as low as -10dB. Simulation results demonstrate that the proposed algorithm can eliminate the effects of additive noise to estimation accuracy. Furthermore, we show that the system performance improved significantly after Doppler shift compensation.