Radar Wireless Spectral Efficiency

The scientific and technical objective of this SBIR Phase II project is to develop and field test a communications system for small, Unmanned Aerial Vehicles (UAVs) that can support video data rates over a link range of greater than 25 km in restrictive terrain. This is the critical technology that enables small UAVs to support the three Navy operational needs. The SSC design, in comparison to prior UAV communications systems, has significant advantages, including and spectrum access and link range. Dynamic spectrum access technologies (i.e., those developed under the DARPA XG Program) overcome difficulties in obtaining spectrum for UAV use. This technology uses ultra-sensitive spectrum detectors in both the UAVs and at ground stations to determine temporally unused frequency channels in specific geographic regions. Link range in restrictive terrain range is improved by three times (3X) compared to 802.11-based downlinks. This is achieved by: (1) Operating at VHF frequencies (only possible when using dynamic spectrum sharing), (2) Using a multi-data rate modem, (3) Using a robust OFDM waveform, and (4) Employing a high performance ground station spatial diversity receiver system.