Mean time to lose lock for a second-order extended tracking rangedelay-locked loop

摘要

The delay-locked loop (DLL) is an appropriate device to guaranteefine synchronization for direct-sequence spread spectrum systems. Forthe performance analysis at low signal to noise ratios the mean time tolose lock (MTLL) represents the most important criterion. The MTLL ofthe second-order extended tracking range DLL is investigated. A coherentloop with a passive loop filter is considered. The MTLL is approximatedby an explicit expression for the leading order term based on results byKramers (1940). The investigations show significant differences for theMTLL of different loop structures. Furthermore, design considerationsand optimal loop parameters are given