Performance analysis of blind timing phase estimators for digital coherent receivers.

The performances of various blind timing phase estimators (TPE) for digital coherent receiver are analyzed. The equivalence among four TPE algorithms is analytically presented, showing that two TPE algorithms applying squaring pre-filters are in fact identical. Three TPE algorithms applicable to Nyquist signals are proposed based on the equivalence analysis. In addition, the impact of receiver bandwidths, spectrum weighting bandwidths and signal timing phases on TPE performance are investigated. The definition of sampling diversity and the analysis of sampling diversity gain for four pulse shapes are presented. The effect of sampling diversity is observed and verified via both simulations and experiments.