A second-order delay-locked loop of a spread spectrum receiver

Abstract

The tracking performance of 2nd-order delay-locked loops (DLL) with high gain for PN code chip synchronization is theoretically analyzed and evaluated by means of a Fokker-Planck equation. The results show that the steady state probability density function of normalized delay error of 2nd-order DLL with high gain is similar to that of a lst-order DLL; for the same mean-squared tracking jitter, the former has 10 log (1 + 1/4/spl xi//sup 2/) (db) less signal-to-noise ratio than the latter. Also, some experimental results are presented. Though only DLL is analyzed, the analytical method is valid for other kinds of tracking loops.<>