No abstract

No abstract

For the first t h e an approximation for the mean time to lose lock (MTLL) of a third-order coherent PN-code tracking loop has been derived. Such loops are essential i n various spread spectrum systems (Global Positioning System, GPS, for example). The computation of the MTLL is based on the singular perturbation method. The application of this calculus to the coherent delay-locked loop (DLL) yields an algebraic expression for the dominant term of the MTLL. The influence of loop offset due to an acceleration rate (jerk) between the transmitter and receiver as well as the optimal choice of the parameters maximizing the MTLL for the loop filter are described. A case study for code tracking of objects with high jerk guided by the GPS is briefly discussed.

No abstract

For the first time an approximation based on the singular perturbation method for the mean time to lose lock (MTLL) of a noncoherent second-order delay-locked loop (DLL) has been derived. Such a loop is essential in direct-sequence spread-spectrum systems. The influence of loop offset due to a constant acceleration (Doppler rate) between the transmitter and receiver as well as the optimal choice of the loop parameters maximizing the MTLL are given. Furthermore, the impact on the bit error probability due to the synchronization error is studied.