Under-Sea Ice Diffusing Optical Communications

In this paper, we propose a novel approach to establish a reliable high-speed broadcast communication link between a group of autonomous underwater vehicles (AUVs) swarm under-sea ice. We utilize the fact that sea ice exists above the AUVs to diffuse the optical beam sent from AUV transmitter. We model this channel using a new seawater-sea ice cascaded layers (SSCL) model in which the vertical channel is divided into multiple layers based on their optical characteristics. The diffusing pattern of the SSCL model is computed using a Monte Carlo numerical ray-tracing technique. We derive a quasi-analytic equation for the channel impulse response (CIR) which is valid for AUV receivers with different configurations, locations and orientations. The communication performance of underwater sea ice diffusing systems is quantified via bit error rate performance, power penalty and maximum achievable bit rate. Our results reveal that, for a snow-covered sea ice sheet with thickness of 36 cm and bare sea ice sheet with thickness 12 cm, the proposed system can achieve a broadcast communication rate of 100 Mbps with ranges up to 3.5 meters and 3 meters, respectively, with BER less than 10
⁻³
and average transmitted power of 100 mW.