In underwater acoustic communication, the energy received is a combination of energies contributed by different rays traversing through different paths due to multiple reflections of the waves at the boundaries, which results in Inter Symbol Interference (ISI). Orthogonal Frequency Division Multiplexing (OFDM), which is a multicarrier modulation technique, is widely employed nowadays. Its advantages include resilience to Inter Symbol Interference, immunity to selective fading, simpler channel equalization, etc. Sea trials being very expensive, underwater acoustic communication scenario can be simulated with any of the available toolboxes. In the simulation studies, Bellhop has been used for generating the channel impulse response based on the assumed environmental conditions. In this paper, OFDM performance has been simulated in underwater communication scenario using 16-QAM and 16-PSK modulation methods. From the simulation studies, it has been observed that 16-QAM based OFDM offers lower bit error rates than that for the 16-PSK based OFDM.

Bellhop, bit error rate performance, modulation, sound speed profile.