Velocity Estimation Algorithm for Mobile Communication Systems with Frequency Offset

Velocity estimation is a critical task for high data rate mobile communication systems which involve a moving platform. The velocity is estimated by measuring the Doppler spread induced in the signal due to relative motion between transmitter and receiver. Residual carrier frequency offset at the receiver has a detrimental effect on the accuracy of Doppler spread estimate. Here, we describe an approach which computes the Doppler spread by finding the minimum point from the estimated autocorrelation function. Since frequency offset appears in the autocorrelation as a phase term, using only magnitude of computed autocorrelation, eliminates the effect of the offset.