Joint Positioning-Communications System Design and Experimental Demonstration

Modern radio systems must adapt to limited spectral access by reducing spectrum demand and increasing operational efficiency. We design and implement a hybrid communications, navigation, and surveillance (CNS) radio system, which simultaneously performs relative positioning and network communications in a distributed network of base-stations and unmanned aerial systems (UASs). Positioning and communications tasks are performed simultaneously with a single, co-use waveform, which efficiently utilizes a limited bandwidth allocation and limits spectrum demand of new entrants. The communications task enables applications such as distributed knowledge base, air traffic management (ATM), and distributed timing synchronization, while the positioning task enables applications such as collision avoidance and automated landing. The positioning task employs a novel time-of-flight (ToF) estimation algorithm that produces high precision (σ <; 5 cm) position estimates with limited bandwidth (10 MHz). The communications task provides an encrypted data link between network nodes which enables phase-accurate timing synchronization and secures the positioning system against cyberattacks such as spoofing. Multi-antenna platforms additionally enable orientation estimation and multiple-input, multiple output (MIMO) communications. We implement this system on a consumer-off-the-shelf (COTS) experimental testbed to demonstrate the functionality of the system and verify theoretical performance limits. The experimental results demonstrate that this technology is a viable alternative positioning, navigation, and timing (APNT) system which can support increasingly dense networks and numerous applications.