ENHANCE BIT SYNCHRONIZER BIT ERROR PERFORMANCE WITH A SINGLE ROM

Abstract

Although prefiltering prevents the aliasing phenomenon with discrete signal processing, degradation in bit error performance results even when the prefilter implementation is ideal. Degradation occurs when decisions are based on statistics derived from correlated samples, processed by a sample mean estimator. i.e., a discrete linear filter. However, an orthonormal transformation can be employed to eliminate prefiltered sample statistical dependencies, thus permitting the sample mean estimator to provide near optimum performance. This paper will present mathematical justification for elements which adversely affect the bit synchronizer’s decision process and suggest an orthonormal transform alternative. The suggested transform can be implemented in most digital bit synchronizer designs with the addition of a Read Only Memory (ROM).