Abstract
Summary form only given, as follows. A recursive online algorithm for joint carrier phase and symbol timing recovery of linear-modulated systems, called recursive pseudo-maximum-likelihood estimation (RPMLE), has been derived on the basis of the maximization of a negative cost function consisting of pseudolikelihood observations, RPMLE uses the inverse of accumulated Hessian matrices of pseudolikelihood functions as weighting matrices to update timing parameters recursively. RPMLE can be applied to baseband PAM timing recovery by a similar approach. Several synchronizers that accommodate either data-aided or non-data-aided estimation, according to whether detected data are directed into the estimators, are presented. It is found that the tracking loop implementation for joint carrier phase and symbol timing recovery developed by Meyers and Franks is a special case of RPMLE with constant weighting matrix. Simulation results show that the rate of convergence of RPMLE is faster than that of stochastic approximation. RPMLE has high noise immunity and can be used to solve synchronization problems of high-transmission-rate systems.