M-ary chaotic spread spectrum Pattern time delay shift coding scheme for multichannel underwater acoustic communication

Pattern time delay shift coding scheme uses the time delay shift values of the Pattern to code the information whose anti-ISI (intersymbol interference) ability is related to the kind and duration of the Pattern. Spread spectrum communications is competent for long-range underwater acoustic communications for its spread spectrum gain, but the low communications rate seriously restricts its application. The proposed new scheme is adapted to the underwater acoustic environment, which integrates the spread spectrum with Pattern time delay shift coding and works at M-ary mode spread spectrum and several communications channels. The scheme could achieve good performance of the spread spectrum and also improve the data transfer rate. The results of lake trial show that the M-ary chaotic spread spectrum Pattern time delay shift coding scheme is robust and feasible.