Reversible Hardware for Acoustic Communications

Acoustic Communications for UUVs

The use of Unmanned Undersea Vehicles (UUVs) as off-board sensor platforms for complex missions such as MCM reconnaissance requires an acoustic communication link for command and control as well as mission data product upload. The communications link needs to be robust and useful in a number of different scenarios. These scenarios include a variety of frequency regimes and a number of different...

Adaptive Beamforming for Acoustic Communications

The basic factors which need to be considered in the design of a practical through water communications system utilising an adaptive beamformer at the receiver are examined. Simulation results demonstrate the feasibility of using such a scheme. It is clear that the multipath phenomenon which has proved so detrimental to a high data rate through water communications link may be effectively count...

Reversible Computer Hardware

Covert underwater acoustic communications.

Low probability of detection (LPD) communications are conducted at a low received signal-to-noise ratio (SNR) to deter eavesdroppers to sense the presence of the transmitted signal. Successful detection at intended receiver heavily relies on the processing gain achieved by employing the direct-sequence spread-spectrum (DSSS) technique. For scenarios that lack a sufficiently low SNR to maintain ...

Aerial Acoustic Communications

This paper describes experiments in using audible sound as a means for wireless device communications. The direct application of standard modulation techniques to sound, without further improvements, results in sounds that are immediately perceived as digital communications and that are fairly aggressive and intrusive. We observe that some parameters of the modulation that have an impact in the...