IMPROVED UNDERWATER WIRELESS COMMUNICATION SYSTEM USING OFDM TECHNIQUE

The paper focuses on Orthogonal Frequency Division Multiplexing (OFDM) based modulation plan to enhance the wireless communication system underwater. The plan partitions the accessible bandwidths divided into numerous overlapping sub-bands where, in contrast to the multipath, the symbol lifetime is lengthy expansion of the channels. Inter-symbol interference is eliminated by this multipath spread on the channels, hence increases the bandwidth that is available. As a result of the procedure, the OFDM approach was used to narrow down the selection of bit error rate (BER) for each subcarrier in the channel for a specific signal to noise ratio (SNR). This method was investigated using Gaussian noise to measure the SNR in a noisy underwater audio channel nonetheless, offered no reflections. Distortion results from the effect at the received signal when inter-subcarriers interference changed throughout time. This was discovered by running multiple simulations using the MATLAB program. When the simulation results were compared to the theoretical values, it was found that the technique improved performance in terms of BER. According to the simulation, the best sub OFDM block number for a given SNR would produce the lowest possible BER. The outcome demonstrates a strong agreement between typical experimental parameters and the theoretical models for OFDM underwater application.

 Keywords - Orthogonal Frequency Division Multiplexing; Quadrature Phase Shift Keying; underwater wireless acoustics; Signal to Noise Ratio; Bit error ratio.