Nonlinear Analysis of an Absolute Value Type of an Early-Late Gate Bit Synchronizer

The steady-state phase noise performance of an absolute value type of early-late gate bit synchronizer is developed using the Fokker-Planck method. The results are compared with the performance of two other commonly used bit synchronizer circuit topologies on the basis of either 1) equal equivalent signal to noise in the loop bandwidth in the linear region, or 2) equal loop bandwidth at each input signal-to-noise ratio Rs. These comparisons are made as a function of Rs. In both cases, the absolute value type of early-late gate yields the best performance (in the sense of minimum phase noise) at every value of Rs.