NLOS and Multipath Detection using Doppler Shift Measurements

This paper proposes a novel multipath detector based on Doppler shift measurements extracted from a frequency-locked loop (FLL). The method is presented in the context of recent analysis about FLL performance, which suggests the Doppler measurement exhibits high sensitivity to multipath in urban environments. A field experiment is conducted as a proof-of-concept for the proposed multipath detector. Our pilot study suggests the multipath detector may be effective enough to detect detrimental multipath, on its own in many cases or as a complement to existing multipath detection methods for high-reliability applications.