Parameters Blind Estimation for Underwater Acoustic DSSS Signal

In recent years, with the exploitation of marine resources and the rapid development of marine environmental research, underwater acoustic communication technology has been a hot topic in the communication field. Underwater acoustic signal recognition and parameter estimation therefore have become increasingly attractive. Direct spread spectrum sequence signal(DSSS) is also widely used in the field of underwater acoustic communication. However, the complexity of the seawater environment is the reason for the multipath interference and low signal-to-noise ratio(SNR), which lead to great challenges and difficulties to the research of the underwater acoustic signal recognition and parameter estimation. This paper presents two efficient algorithms for estimating the parameters of the underwater acoustic DSSS signals. An approach of Triple Correlation Function(TCF) of the underwater acoustic DSSS signals is proposed, which can estimate the Pseudo Noise(PN) code sequence blindly. The period of PN code sequence is estimated by the reprocessed power spectrum method. Theoretic analysis and experimental results show that the two approaches are very robust, working well in the underwater acoustic environment with multipath interference and low SNR.