Generic Reusable Hardware/Software Co-Design Implementation of a Complete FH-FSK Modem for Robust Multi-User Acoustic Underwater Communication and System Validation on a FPGA

Abstract

Underwater communication with autonomous underwater vehicles (AUVs) has strong demands on the modems caused by the constantly changing signal propagation (multipath propagation, scattering, diffraction and refraction at thermal layers, etc.) of the underwater channel. These demands typically lead to a modem designed to match specific conditions. This results in two major problems, first we do not want to develop for each changing environment a specific hardware and second we need a robust communication to distribute necessary information about the state of the system, current condition of the environment or to coordinate group missions. In this paper we introduced a approach to serve booth of the problems. We implemented with a flexible generic design a robust underwater communication system. The paper introduce a designed approach for a generic reusable acoustic underwater communication based on a pipelined data stream processing system on a Field Programmable Gate Array (FPGA). Exploiting the inherent synchronization mechanism of an hand-shake-based streaming bus interface to form arbitrary long pipelines composed of detached and reusable modules representing the coding and modulation algorithms without the need of an external coordination mechanism. We show that our approach is feasible, matches the problems and can easily be changed or extended to a Multiple Input Multiple Output (MIMO)-system while the recommendation on energy consumption is nearly equally and area is reduced by 45% compared to other system implementation.