A design for timing pulse acquisition in underwater multipath environments

A design is proposed for acoustic timing pulse acquisition, and it is suitable for uses in reverberant multipath environments. This scheme uses two identical broadband pulses for timing, and it is motivated by passive phase conjugation. It is simple in signal processing. The first pulse is used as a probe pulse to estimate the channel impulse response, and then the received probe replaces the replica signal later to catch the second pulse. Within coherence time, a fixed threshold can be preset. A detector makes a decision on the correlation coefficient between the first pulse and the second one, as the coefficient has a great immunity to channel impulse response. In this way, it is easy and robust for receivers to realize acquisition. It shows advantages for independent receivers operating in the shallow water channel.