Cyclic shift keying spread spectrum OFDM method over underwater acoustic channel

Aimed at solving the problem of low data rate of direct sequence spread spectrum underwater acoustic communication and that of complexity of the receivers of M-ary spread spectrum underwater acoustic communication, cyclic shift keying spread spectrum OFDM (CSK-SS-OFDM) method is proposed to improve bandwidth efficiency and bit rates. This method has high data rate compared with conventional direct sequence spread spectrum underwater acoustic communication. The performance analysis and simulation comparison of OFDM and DSSS-OFDM is provided in this paper. Compared with conventional OFDM, CSK-SS-OFDM can obviate the PAPR problem and obtain a robust link at a lower SNR; Compared with DSSS-OFDM method, CSK-SS-OFDM can improve the bandwidth efficiency with losing a little BER performance.