Spectrum-Aware Sensor Optimized Signaling (S2OS)

AiRANACULUS in association with Sparton DeLeon Springs (Transition Partner) proposes an innovative Spectrum-aware Sensor Optimized Signaling (S2OS)  for data uplink information transfer improvements that can double, triple, and quadruple  the current uplink data throughput from sonobuoys with minimal increase in channel bandwidth by using Multi-User Detection (MUD) technology at the Receiver with Partially Overlapped Transmit Channels that  maximizes uplink data transfer speeds. The objective of this project is to develop a solution that enables large amounts of data to be transferred or uplinked from Anti-Submarine Warfare (ASW) sensors systems, including sonobuoy sensor systems, to airborne platform receivers. The Navy is transitioning to digital communication links for all its ASW sonobuoy sensors to aircraft information transfer. Currently, transition to digital communication links for data transfer from airborne ASW sensors, including sonobuoys, is limited by the combination of limited Radio Frequency (RF) bandwidth available to use, and the need to sample and analyze large acoustic bandwidths greater than 40 kHz for transfer over the data link. The current maximum data rate to the aircraft is 320 Kbps in one channel located in the 136 MHz-170 MHz VHF band. If the Navy wanted to get multiple hydrophones and/or wide acoustic bandwidth data from the buoy, then this narrow pipe is a constraint. We focus on selecting modulation and demodulation schemes that provide higher spectral efficiency by increasing raw data rate per given channel bandwidth while considering hardware limitations, most notably the transmit Power Amplifier (PA) efficiency. Several different modulation schemes to improve the uplink data throughput were evaluated by examining three metrics, namely, performance (BER), spectral efficiency (bits/s/Hz), and required power amplifier rating (Watts). BER performance of each modulation scheme was verified by Monte Carlo simulations. After extensive analysis and simulations, we propose the improved sonobuoy uplink radio communication system with flexible channel configuration options for deployment of sonobuoys with increased and mixed data rate capability using partially overlapped channels using Gaussian Minimum Shift Keying (GMSK) modulation and MUD receiver. Exemplary deployment scenarios show that with 2 Watt and 3 Watt PAs, data throughputs of 640 kbps over 320 kHz channel and 960 kbps over 750 kHz channel can be achieved with the same radio coverage area as the legacy 320 kbps GMSK system with 1 Watt PA. Based on these technologies that we already have proven to work, our proposal aims to improve and expand the technologies to the sonobuoy sensor signal applications. By combining efficient spectrum-aware sensor signal processing and state-of-the art interference cancelling multi-user receiver, we can achieve the goal of data throughput increase that can be demonstrated not only in the lab but also in the realistic field trials.