Robust DLL discrimination functions normalization in GNSS receivers

Abstract

In this paper we have analyzed the normalization problem in the evaluation of the DLL discriminator function. We know that the parameter setting of the DLL elements is strictly related to the definition of the discriminator function. If this function becomes sensible to the prompt fluctuations, due to a degradation of its estimation, also the loop characteristics (noise equivalent bandwidth, pole position, etc...) change. In order to keep the discriminator function as close as possible to its noise-free definition, we have proposed here a method to make the evaluation of the S-curve more stable.