Alternative approach of constructing a digital underwater communication system with negative SNR as well as higher security

Underwater noise and fading characteristics are known to exhibit the denser ever reported noise environment that prevents the transmission of clean high speed digital signals. On the other hand, the low powered ROVs, and the narrow band acoustic signaling confront underwater signaling tasks even further. Traditionally, as the signal-to-noise ratio is increased, a better BER performance is achieved. In this context, the most advanced channel coding and signal processing techniques are employed to achieve a good BER performance by involving encoders and decoders for suitable SNR values based upon probability laws, not forgetting the inevitable hard decision device and expensive filters. Indeed, this paper proves with specially randomized input data and by a faultless simple detector, an errorless signaling with negative SNRs, negligible interference and multipath effects is possible. The proposed method can demonstrate further advantages over similar existing modulation techniques (e.g. spread spectrum systems) and it is not sensitive to channel delays which lead to hard synchronization and ciphering attacks.