Orthogonal code shift keying spread spectrum underwater acoustic communication

Abstract

Code shift keying (CSK) is generally used to overcome the spreading gain versus data rate limitation in underwater acoustic (UWA) communication as generalized M-ary spread spectrum technology. In addition, the concept of orthogonal CSK is introduced into the UWA communication to achieve higher rate, mitigate crosstalk from the other thoroughfare and utilize the redundant information of CSK adequately. In this paper, we propose a new scheme employing orthogonal double thoroughfare CSK spread spectrum UWA communication with utilizing code phase information combined. First, each symbol integration output form of the proposed method is deduced. Furthermore, the property of orthogonal CSK is analyzed and its bit error rate is investigated as compared with conventional CSK and double thoroughfare CSK via simulation. Finally, the validity of simulation comparison is verified in experiment. 580.6 bps data rate of the proposed communication scheme is realized in 104 bit volume and 4 kHz bandwidth efficiently. It is shown that the proposed method provides significantly improved communication performance through formula, simulation and test.