Spectrum Sensing and Sharing by Cognitive Radios in Position, Navigation and Timing (PNT) Systems

ABSTRACT: Echo Ridge (ER) proposes to design an architecture and key algorithms to support spectrum sharing for PNT that focuses on spectrally congested and high likelihood operational scenarios. The architecture defines the new functionality/necessary improvements to the PNT elements (broadcasts satellite and MGUE DSA operation), spectrum sensing elements (signal sensing detection/characterization, white space identification and broadcast transmission strategy), and communication elements (sensing function to MGUE and space segment through control segment) to support spectrum sharing for PNT. The architecture design and features for each segment will be presented based on a trade space analysis of alternatives. Using the architecture and algorithm design, an estimate for the potential improvement in PNT will be produced for the selected example operational environments. We expect spectrally congested/high operational likelihood environments to be composed of many sensed non-contiguous white space volumes with different available frequencies which are smaller than antenna beam patterns. We will research and present a method where measurements in the discontinuous and disparate sharable spaces can be used jointly by MGUE to estimate PNT. This white space volume-large coverage area satellite footprint circumstance represents an operational challenge which is very different than the traditional DSA communications environment.; BENEFIT: This research will provide an understanding of what improvements in PNT performance are possible through spectrum sharing, and define the necessary elements in an effective spectrum sharing architecture. It explores a technological path towards addressing the growing concern over the civilian and military reliance on GPS and the threat of unintentional interference and intentional jamming. The technologies proposed solves routinely identified problems in the military, public, and commercial marketplaces (unreliable PNT in challenging environment (indoors, urban canyons, jamming)). The proposed research and development is oriented to produce structured, reusable intellectual property packages that can be made available to prime contractors for inclusion into their product lines.