Evaluation of inner product-based demultiplexing of vortex-based underwater acoustic communications signals in realistic environments.

Acoustic vortex beams have garnered recent interest as an avenue to improve underwater acoustic communication bandwidth and speed. Design and deployment of these systems in ocean environments and at operational ranges has yet to be demonstrated due to the challenging and dynamic nature of the underwater acoustic environment. This manuscript presents methods to model the time series of vortex-based communication signals in ocean environments using ray tracing algorithms. The methods are used to assess the effects of Doppler, ocean turbulence, positional error, and range-dependent environmental parameters on the inner product demultiplexing of the communication signals encoded in the acoustic orbital angular momentum.