URSINI - A LC/LPD Waveform for the COPPERHEAD Radio

URSINI is a low-cost/low probability of detection (LC/LPD) waveform hosted on the proven Motorola COPPERHEAD radio platform (TRL-8). The URSINI design places an emphasis on achieving low costs without compromising on LPD capabilities. URSINI is based upon established techniques which are combined in a novel fashion, reducing risk in the implementation, and maximizing the feasibility of achieving a LC/LPD capability. The foundation of our approach is the Motorola COPPERHEAD radio and an associated RF front-end module (FEM). We believe a solution based on the COPPERHEAD radio is ideal for the Army’s needs due to the existing TRL level, low cost/power/size, sufficient FPGA fabric for critical LPI/LPD waveform processing, and known environmental qualifications. COPPERHEAD has previously been supplied to the US Government for multiple programs, including a combat evaluation effort. The SDR has two integrated narrowband 2-Watt power amplifiers and three dedicated receiver chains to provide broad coverage over multiple RF bands. URSINI provides strong LPD characteristics yet can be feasibly implemented on low-cost hardware. URSINI employs long sequence DSSS spreading followed by a chaotic phase scrambler and custom pulse shape filters to provide a featureless waveform at SNRs well above the intended operating range. The LPI/LPD nature of the URSINI waveform and the feasibility of implementing it on the COPPERHEAD radio hardware was proven in Phase I of this program. The URSINI ad-hoc network will utilize a number of overlapping frequency channels with one frequency and spreading code being configured as the control channel.  This design supports an implementation on constrained low-cost hardware. The remaining frequency channels and codes are then used for data transmission to provide frequency diversity, combat in-band interference, and allow for multiple access without compromising the LPD nature of the waveform. This combination of the COPPERHEAD radio and the URSINI waveform will provide the Army with a capability that supports flexible, below the noise floor, communications in ad-hoc battle groups. Estimated performance of this platform will meet, or exceed, the desired operating requirements and hardware modifications have been identified that will reduce the cost below the desired threshold.