Underwater acoustic communication using passive phase conjugation

A new method for underwater acoustic communication called passive phase conjugation is evaluated. The method begins with a source transmitting a single probe pulse. After waiting for the multipathed arrivals to clear, the source then transmits the data stream. At each element in the distant receiving array, the received probe is cross-correlated with the received data stream. This cross-correlation is done in parallel at each array element and the results are summed across the array to achieve the final communication signal suitable for demodulation. The parallel processing makes the method computationally efficient and allows near real-time communication