Eigen-based Doppler estimation for differentially coherent CPM

Eigen-based methods are developed for obtaining fast and accurate Doppler estimates in both land-mobile satellite and urban microcellular applications. By showing that the correlations of a set of differentially processed CPM signals have the same form as the autocorrelations of a complex exponential in noise, eigen-based spectral estimation techniques are used to provide improved Doppler estimates in noise. The eigen-based Doppler estimators are shown to have significantly less variance and mean square error than previously proposed Doppler estimators that use only simple averaging