LAUSR

The tracking performance of a global navigation satellite system (GNSS) receiver is altered by signal distortions of different kinds, ranging from transmitter and receiver imperfections to various forms of channel impairments. Accurate modeling of the receiver performance in the presence of signal distortions allows to improve GNSS-based positioning, tighten error bounds, and thus enhance the integrity and the availability of the GNSS services. We present a model for the code-tracking loop performance of a GNSS receiver when the GNSS signal undergoes an arbitrary cascade of nonlinear and linear distortions. The impact of the distortions on the pseudorange estimation is analyzed by deriving closed-form expressions for the bias and variance of the tracking error. These analytical expressions are based on the well-known open-loop linearized delay-locked loop model. The validation is then performed using a GNSS software receiver that evaluates the tracking error numerically.