Synthetic aperture navigation algorithms applied to a driving user in multipath environments

Abstract

The accuracy of radio frequency based navigation systems is dependent on the precision of ranging measurements, which are greatly limited by multipath propagation in severe environments. Synthetic aperture techniques have been proposed to mitigate the effects of multipath, leveraging user motion with array processing and beamforming techniques to isolate the line of sight component, thus reducing the impacts of propagation. This concept has several advantages, including the ability to obtain accurate line of sight measurements even in the presence of stronger multipath using a single element antenna, and reduced reliance on signal bandwidth to mitigate multipath. To test the algorithm, we designed an experiment in which RF data was collected by a driving user from two beacons, one serving as a control and the other testing synthetic aperture techniques. Here, we quantify Doppler estimation performance of the synthetic aperture techniques for the direction of arrival of the line of sight signal and of multipath in real-world environments.