Joint Positioning-Communications: Constant-Information Ranging for Dynamic Spectrum Access

Spectral congestion limits the opportunities and performance of radio frequency (RF) systems. Spectral isolation sufficiently mitigates this congestion for a small number of users but does not offer a scalable solution once the entire spectrum is occupied. Dynamic resource management supports higher user densities by constantly renegotiating spectral access depending on need and opportunity. This approach promises efficient spectral access but is predicated on cooperation between different types of RF systems, which is a significant paradigm shift for many legacy technologies. Intelligent transportation systems (ITS) rely on several different types of RF services such as radar, communications, and positioning, navigation, and timing (PNT). RF Convergence demonstrates that many of these systems can be executed simultaneously using efficient cooperation strategies, which improves performance and limits spectral access. In this study, we demonstrate a simultaneous positioning, navigation, timing, and communications system that cooperatively executes multiple RF services. We define a constant-information ranging strategy that maintains constant information learned about an incoherent moving target by modulating the revisit interval to minimize the number of interactions. This significantly reduces spectral congestion and offers a control mechanism to dynamically manage spectral access. We validate the constant-information ranging algorithm in a simulation environment where we observe a 91% reduction in spectral access for a particular flight path while maintaining a 3 cm precision in ranging.