A simulation model of fading in an underwater channel

With the advent of very large scale integrated circuits for digital signal processing, it is now possible to implement highly sophisticated techniques for modulation, demodulation and detection of digital signals for underwater communications applications. The computer simulation model presented is based on an understanding of all the signal impairments associated with an underwater channel. The model utilises baseband binary (multilevel QAM) transmission of digital data in the presence of volume, surface and bottom scatterers in the sea. It employs Rayleigh multipath fading simulation, i.e. time-varying changes in amplitude and phase of the received signal. Applications of this research include real time monitoring of a diver´s physiology, oceanographic data telemetry, and diver or submersible navigation and communications