A Robust Wide Synchronous Digital Chaotic Communication Scheme in Shallow Water Channel

This paper proposes a underwater acoustic coherent chaotic communication scheme which is suitable for shallow water channel mainly at 80bps rate. The encoding uses a decoupling mode, and the modulated signal doesn´t contain common binary information. Orthogonal basis signals are engendered directly by Gaussian white noise carriers. The tolerance of time synchronization and the ability of resistance to inter-symbol interference (ISI) are achieved. The binary mapping decoding is engendered in correlation demodulating mode, and the copy correlator is used to match processing. Some problems have been considered, such as the system detection threshold, Doppler matching, the frequency compensation of copy sample, etc. The theoretical calculation and test method are provided. We use 1 kHz narrowband signal to enhance the ability of anti-dispersive fading in shallow static and dynamic experiments. Robust communication is achieved while the receiving threshold is above 0dB, and meanwhile the transmission loss rule is verified in shallow water channel.