Comparison of Average Performance of GPS Discriminators in Multipath

Signal multipath in GPS leads to undesirable tracking errors and inaccurate ranging information. The extent of the tracking error in compromising the receiver performance depends on the multipath amplitude, delay, and phase relative to the direct path. The coherent discriminator and the noncoherent early-minus-late power discriminator offer different tracking accuracy and sensitivity to multipath parameters. In this paper, we develop analytical expressions of the average performance of the two discriminators over the multipath phase distribution and other propagation channel variables.