Performance Evaluation of Non-uniform Modulation of OFDM Subcarrier in the Underwater Acoustic Environment

摘要

In this paper, we evaluated the OFDM performance with Non-uniform Modulation. Then the effect of multipath fading channel analyzed using Additive White Gaussian Noise (AWGN). The types of modulations are Binary phase-shift keying (BPSK), Quadrature phase-shift keying (QPSK) and 16-Quadrature Amplitude Modulation (16-QAM). These modulation techniques were used to develop Nonuniform modulation of OFDM systems. In the simulation results, by maintaining a BER value of 0.001 this system is able to transmit 14443000 bits. Meanwhile, when it is sent by using fixed modulation such as BPSK, QPSK, and 16-QAM respectively i.e. 5252000 bits, 10504000 bits, and 21008000 bits on the same bit error rate (BER) value. The 16-QAM modulation is capable to transmit more bits, but this scheme requires more power. However, Non-uniform Modulation is able to improve bits efficiently with higher data rate compared to fixed modulation techniques.