Advanced RF using Spiral Modulation

Stronger RF links extend eVTOL/UAM capabilities, providing higher data throughput and reduced SWaP. At the physical layer, existing radio communications methods are approaching their theoretical spectral efficiency limit. Astrapi’s Spiral Modulation makes use of symbol waveform alphabets designed using polynomials. Polynomials allow for a very large symbol waveform design space, which can be used to create symbol waveform alphabets with greater inter-symbol distinguishability, and therefore greater noise resistance, than traditional signal modulation technology. Significant spectral efficiency improvement is possible with Spiral Modulation because it fully exploits the capabilities of a continuously non-stationary spectrum. Unlike classical channel capacity theory which contains an implicit assumption that the spectrum is at least approximately stationary, Spiral Modulation introduces polynomials with continuously varying amplitude. A recent Beyond-Line-of-Sight (BLOS) troposcopic scatter telecommunications project resulted in third-party validation for a 2-4 dB signal power advantage compared to traditional signal modulation. Astrapi is now transitioning its TRL 4 software defined radio (SDR) technology to our second-generation state-of-the-art Xilinx Zynq ZCU111. Our ZCU111-based SDR implementation will provide a prototype capable of specialization into many implementations, including to support eVTOL, UAM and many other missions, initially designed for Near Earth Networks (NEN) ground stations and then in-orbit SDRs.