Optimum stuff threshold modulation schemes for digital data transmission

The method of 'stuff threshold modulation' (STM) is widely used with pulse stuffing in network synchronizers to obtain reduced jitter power at the output of desynchronizers. Of the various STM waveforms that appear in the published literature, none have been selected as an optimum for a given set of synchronizer-desynchronizer operating conditions. This paper formulates the problem of STM waveform optimization for arbitrary desynchronizer PLL characteristics and a specified range of synchronizer clock frequency offsets. By comparing three waveforms, i.e. a random sequence, a saw tooth sequence and a modified wave sequence, it has been shown that one particular type of STM waveform does not always produce optimum jitter performances under all conditions.<<ETX>>