Active average intensity based on single vector sensor

Abstract

Code divided multiple access underwater communication based on single vector sensor is studied in this paper. The most common methods to estimate azimuth with self-directivity of single vector sensor are average sound intensity method and complex sound intensity method, however, for the same frequency band multi-users, theoretical limitation for these methods is only two users.Spread spectrum communication is featured with strong anti-multipath, anti-interference, secret-keeping and communication web composing ability. Active average intensity method, which measures azimuths of multi-users simultaneously with the excellent correlative characteristics of pseudo-random code in spread spectrum communication, is proposed in this paper. Simulation and experiment for same frequency band spread spectrum multi-user communication testify the feasibility and utility of active average sound intensity method. With the estimated azimuth, vector combination can be generated to adjust the directivity of vector sensor, achieve multi-user beam communication, inhibit multi-path interference, and enhance processing gain and lower error rate. Key words: underwater acoustic communication; CDMA; single vector sensor; active acoustic intensity average