STATISTICAL DISTRIBUTION OF PCM FRAMING TIMES
Abstract
This thesis evaluates the performance of interleaved and block synchronization methods in PCM systems. Three performance measures are defined search time, true maintenance time and false maintenance time. Equations of the statistical distribution and mean of framing search time have been developed for both framing structures assuming a general maintenance algorithm. A number of currently used or recently proposed maintenance algorithms have been investigated. The predicted distribution and mean of framing times have been verified by measurements on a laboratory model. The thesis presents graphs of search time distribution which illustrate the effects of channel error rates, sync word pattern and other system parameters. Optimum framing system design is discussed based on the mean framing time equations. The results of the thesis work have been applied in industry.