Doppler frequency estimator performance analysis

A novel realistic model for Doppler signals is investigated. The intended application is the accurate estimation of a train´s speed using an onboard Doppler radar. The signal is shown to be conveniently modeled by a sine wave amplitude modulated by an autoregressive process. The spectral properties of this model are derived and used to define a relevant frequency estimation algorithm based on conventional ARMA (autoregressive moving average) spectral estimators. Statistical properties of the algorithm (covariances and cross covariances of estimated frequencies) are presented to show there could be a considerable improvement in the estimation of the frequency. The performance of this algorithm is evaluated by means of simulation and compared with a conventional estimator