Joint time and phase recovery for CPM and its asymptotic behavior

A novel joint timing and phase recovery technique is proposed for CPM systems based on Kalman filtering and an approximate representation of CPM signals with nonorthogonal exponential expansions (nOEE). In contrast to existing maximum likelihood methods that cannot synchronize partial response M-ary CPM signals, simulation results show that the proposed synchronizer is robust in acquiring and tracking both time shift and phase offset on either time-invariant or time-variant channels. Moreover, the asymptotic stability and convergence of the synchronizer is analyzed, including the effect of statistical channel modeling errors on the convergence characteristics