Assessment of UWAC System Performance Using FBMC Technique

Abstract

At the physical layer, Underwater Acoustic Communication (UWAC) channels present many challenges for efficient communications, which feature both long delay spreads and serious Doppler effects. The waves and motions at the surface of the sea are the main causes for these effects. The complexity at the receiver increases along with the symbol rate, thereby increasing the burden of the channel. Orthogonal Frequency Division Multiplexing (OFDM) which is a form of multicarrier modulation has been effectively used for UWAC recently because of its ability to handle long dispersive channels reducing the complexity of the channel equalization. However, Inter Carrier Interference (ICI) is introduced by the Doppler effects that destroy the orthogonality of the subcarriers. To overcome the effects of OFDM, an emerging technique known as Filter Bank Multicarrier Communication system (FBMC) is used in UWAC. The high capacity of the transmission bandwidth in FBMC systems can be accomplished by applying Offset Quadrature Amplitude Modulation (OQAM). Because of cyclic prefix deletion, FBMC/OQAM can arrange higher spectral efficiency when compared to OFDM. This paper worked on both OFDM and FBMC/OQAM by considering the losses and noise effects in UWAC environment and explained their performances with respect to Bit Error Rate (BER).