Adaptive Doppler frequency shift estimation for OFDM systems

Orthogonal Frequency Division Multiplexing (OFDM) is sensitive to the system frequency offset, while in high speed movement Doppler frequency shift is the main factor which causes the system frequency offset and result in inter-carrier interference (ICI) and degrade system performance. This paper proposes an adaptive Doppler frequency shift estimation method based on autocorrelation function of the time domain channel estimation. Compared with the conventional method, the estimation parameter in the proposed method is adjusted adaptively according to the velocity of mobile station, so the method has a larger estimation range. The simulation results include the performance comparison of this proposed method and the conventional method, NMSE comparison, and the performance comparison under different signal-to-noise ratio (SNR). Through investigating the simulation results, the proposed method is verified to be able to generate the accurate estimation results and robust in the noise.