Performance Analysis and Parameter Optimization of DLL and MEDLL in Fading Multipath Environments for Next Generation Navigation Receivers

In this paper the choice of DLL parameters is studied with special focus on multipath and Doppler sensitivity. The envisaged application is code tracking on navigation receivers and the multipath fading environments defined for next generation navigation systems are considered. Given the particular properties of these propagation environments, multipath estimating delay lock loop is shown to have the best performance within a particular signal to noise ratio range if some specific parameters such as the Predetection Integration Time and channel estimation time interval match the time-varying nature of the channel and the spacing in the early-late scheme is chosen accordingly to the multipath characteristics.