A New Modified Short-Multipath-Insensitive Code Loop Discriminator

Multipath error is one of the most significant error sources that degrade the performance of global positioning system (GPS) receiver. Several studies have been carried out to reduce its effects. However, most of these studies achieve only acceptable performance with medium and long relative delay multipaths. In this paper, we propose a modified short multipath insensitive code loop discriminator (MSMICLD) using a non-coherent dot product power discriminator function. The proposed discriminator is insensitive to short multipaths that have a relative delay less than 0.5 chips. The MSMICLD is modeled using MATLAB and its performance is evaluated with and without multipath for three different types of receivers: infinite pre-correlation (front-end) bandwidth (BW), 2 MHz pre-correlation BW and 8 MHz pre-correlation BW. Moreover, the performance of the proposed MSMICLD is compared with that of the conventional SMICLD. Simulation results show that the MSMICLD has the ability to mitigate the short multipaths in the considered receivers. The obtained results also show that the performance of the proposed discriminator outperforms that of the conventional SMICLD in terms of simplicity for all short relative delay multipaths.