A Multi-Frequency Digital Communication Technique for Acoustic Channel with Multipaths

A new transmission scheme using a modulation technique based on Continuous Phase Frequency Shift Keying (CPFSK) is detailed for communication in a multipath acoustic channel. The received signal is demodulated by a new demodulation method conceptualized on the Sliding Discrete Fourier Transform (SDFT) algorithm. The performance of the proposed scheme is evaluated analytically and by computer simulations. The effect of synchronization error on the received signal is obtained and the error performance of the system is evaluated in the presence of Gaussian noise. The analytical and simulation results reveal that the proposed scheme is a reliable means for underwater communication in multipath channels. Due to the simplicity in implementing the SDFT algorithm with commercially available integrated circuits, the system is attractive in situations where little power and little space are required, such as in remotely operated vehicles.