Energy Efficient Doppler Assisted Channel Estimation for Highly Mobile OFDM Systems

The complexity of channel estimation algorithms is of critical importance in high mobility orthogonal frequency division multiplexing (OFDM) systems. To reduce the complexity of the algorithm, the existing channel estimation algorithms take advantage of the correlations between the channel coefficients. However, they do not take into account the variations of the correlations with the delay tap. In this paper, we consider the change in correlation between channel coefficients for different delay taps. By considering these variations, the number of computations needed for channel estimation can be decreased. This results in a reduction in the circuit energy. The simulation results show that the proposed scheme consumes less total energy per bit for transmission distances less than about 170 m when the mobile speed is 324 Kmph