Mohammadjavad Jannati

  Abstract:

  In this thesis cooperative communication approach in underwater acoustic systems is studied. For this purpose, firstly, features of acoustic waves and sound are studied. After that cooperative communication in radio channels is studied. Then work is extended by working on underwater acoustic channel and its features.

  In this thesis a new method to improve performance of underwater acoustic channel called “adaptive frequency controlled transmission” is proposed. Then cooperative communication in underwater acoustic channels is simulated. “Amplify and forward” and “decode and forward” schemes are adapted and applied to underwater acoustic channel. After that, combination of cooperative approaches and adaptive frequency controlled method is applied to underwater acoustic channel.

  In continuation, work on active nodes and rayleigh fading in underwater acoustic channel is begun by using alamouti coding and transmission scheme.

  Finally combination of alamouti approach and adaptive frequency controlled scheme applied to underwater acoustic communication channel and made proper performance improvement on it.

  Simulations of this thesis shows that approach of cooperative communication can make proper improvement on bit error rate performance of underwater acoustic communication in underwater channels.

  Date: 21th of June 2010 by 3 PM

  Location: Class 203 of electrical engineering department