Eliminating co-location radio interference with photonic-enhanced spectrum management in cognitive radio networks

Abstract

Co-location of RF emitters (communications plus jammer) is a problem in tactical operations where the goal within a tactical platform is to maintain blue force communications and deny (jam) red force communications or, indeed, any red force use of spectrum. Dynamic Spectrum Access (DSA) on the DARPA neXt generation (xG) communications program [1] has a goal to sense and share spectrum for more efficient use. A port and test of this DSA capability from a commercial radio to a tactical radio showed significant improvement in tactical communications in a jamming environment. The sense and respond capabilities discussed in this paper have been extended on IRAD to include a photonic-assisted, frequency converting front-end module utilizing heterodyne frequency conversion to generate a wide range of carrier frequencies for DSA transmission, and heterodyne down conversion along with photonic signal processing techniques to generate nulls at RF frequencies to protect the radio from intermodulation distortions arising from nearby strong RF signals (friendly jammer). Some of the DSA capabilities in the field tests were enabled only by somewhat counter-intuitive measures on the military radios. This has led to the development of a mission-based ontology that considers the mission, the cognitive radio capabilities (DSA and more) and the traditional RF parameters in a network of platforms as a system. The gains from an ontology- based solution are discussed.