A real-time high data rate acoustic communications receiver demonstration system

This paper provides a review of the development of a real-time acoustic communications system based on efficient signal processing techniques capable of real-time operation at data throughput rates of up to 24 kbps with minimal re-synchronisation overhead. This system utilises passband open-loop and baseband closed-loop Doppler control to correct for inter platform movement. Novel attributes include implementation of an outboard 16 element array with digital telemetry to permit mid-channel array positioning and to allow mechanical de-coupling of receive platform heave motion. Baseband closed-loop Doppler control and low complexity complex-LMS decision feedback routines have been implemented to permit real-time operation. Results from sea-trials are presented which show robust real-time operation at various ranges and relative inter-platform velocities and with varying signal to noise levels. Descriptions of the various system architecture components are provided.