Velocity estimation for OFDM based communication systems

We investigate a velocity estimation algorithm for orthogonal frequency division multiplexing (OFDM) based communication systems. Since OFDM is a strong candidate for future mobile broadband wireless communication systems, the channel estimation, in this case two dimensional Wiener filtering, should work in a wide range of user velocities (0 to 350 km/h) and different delay spreads. To keep the channel estimation errors as small as possible, an adaptation of the filter coefficients to the current channel state must be realized. We present a modified version of a previously published velocity estimator and present error estimations to predict the reliability of the estimator. It is shown, that the estimator is very reliable compared to the accuracy requirements of the adaptive Wiener filter in a wide range of channel states. The algorithm can be applied directly to OFDM systems with transmit diversity (TD) and to OFDM MIMO systems.