Investigation of capture time in digital synchronizers

The capture time of baseband digital symbol synchronizers is investigated. Generalized expressions are developed for capture times, and these capture times are found to be influenced by added disturbances as well as by timing error detector characteristics. The question of when a synchronizer can be considered synchronized for performance comparison purposes is discussed in detail. Further analysis is carried out for the case where the disturbance can be represented as additive Gaussian noise. A complete evaluation of capture time is then performed for both a linear and a nonlinear timing error detector characteristic. The evaluated performance is compared with numerical simulation and found to agree closely