DCT based OFDM for Underwater Acoustic Communication

Discrete Cosine Transform based Orthogonal Frequency Division Multiplexing (DCT-OFDM) is proposed for the first time for Underwater Acoustic Communication. Underwater acoustic channels are characterized as doubly spread channels in time and frequency. The orthogonality feature of conventional OFDM is also provided by inverse DCT (IDCT)-DCT structure with the added advantages of reduced implementation area and increased computational speed as only real calculations is required. This system provide higher peak to average power ratio (PAPR) reduction and achieve better noise immunity and hence better bit error rate (BER) performance than standard OFDM, while maintaining a low implementation cost. Simulation results show noticeable improvement in the performance.