Noncooperative detection and parameter estimation of underwater acoustic DSSS-BPSK signal

Abstract

Because of its high security and low probability of interception performance, DSSS-BPSK signal has been widely used in underwater acoustic engineering field. It is usually quite difficult to detect this kind of signal in noncooperative and real-time occasions. Based on the autocorrelation detection algorithm, a combination method of frequency band-divided pre-filteting and power spectrum reprocessing, which can be used to implement the real-time detection of underwater acoustic DSSS-BPSK signal, is put forward in this paper. This method can also be used to the estimation of the pseudo-random code period and chip width, and no prior knowledge of the intercepted signals is necessarily required. With frequency pre-filtering, it can not only suppress the strong ocean noise effectively, but also make the real-time detection possible via the FFT algorithm. The results of computer simulation and practical experiment have both validated the feasibility and validity of this method.