Analyzing the effects of mobile station circular motion on early-late tracking loops using the normalized timing error PDF derived from a Fokker-Planck equation

Abstract

This paper analyses the effects of circular motion on tracking loop performance. The normalized timing error PDF which is derived from a Fokker-Planck (F-P) equation is used. The analysis shows the applicability of modeling the tracking loop response using a stochastic model. It further shows that the circular motion generates uncompensated power losses due the variability of multipath time delay generated by the circular motion. Unlike what is previously suggested by literature, the paper recommends increasing the bandwidth of the tracking loop in order to compensate for the generated power losses instead of increasing the estimated time delay offset.