Shallow-water acoustic communication with high bit rate BPSK signals
van Gijzen, M.B.
van Walree, P.A.
TNO Physics and Electronics Lab, Hague, Netherlands
BPSK signals have been defined for transmission through a shallow-water acoustic communication channel. The signals were accompanied by two displaced carriers to facilitate carrier recovery. To correct for the adverse effects of time spreading, a pseudo-random learning sequence was transmitted ahead of the communication signal. The signal processing consists of a shift to baseband guided by the displaced carriers, a least-squares equalizer tuned to the received learning signal, coherent addition of reconstructed baseband signals (corresponding to selected channels of the receiving hydrophone array), and bit restoration with a decision-directed equalizer. In this manner, bit rates up to 4 kbit/s are successfully dealt with in moving-point-to-fixed-point communication. The main risk appears to be the fading of a displaced carrier.
Acoustic signal processing
To reference this document use:
Communication channels (information theory)
Least squares approximations
Phase shift keying
Binary phase shift keying
Least square equalizer
Pseudo random learning sequence
Shallow water acoustic communication
IEEE, Piscataway, NJ, US
Oceans 2000 MTS/IEEE, 11-14 September 2000, Providence, RI, USA,, 3, 1621-1624