Research Of Reducing OFDM PAPR In Underwater Acoustic Communication Systems

Orthogonal Frequency Division Multiplexing (OFDM)technology in recent years is the rise of a wireless channel to achieve high-speed data transfer of new technologies. It is a multi-carrier modulation technique which has high transfer rate . It has a strong resistance for inter-symbol interference and selective fading channel and other characteristics. Therefore OFDM technology has highly theoretical value and practical value in the underwater acoustic communication application and research field. OFDM technology but also has its disadvantage that can not be ignored ,which is high PAPR. The higher the peak-average power ratio of System, the greater instantaneous volatility of OFDM transmitter output signal. Usually the non-linear of the power amplifier will lead to nonlinear distortion, nonlinear distortion will lead to inter-subcarrier interference and cross-band radiation, damage among subcarriers orthogonality, resulting in overall system performance degradation . Therefore , OFDM systems need to address the problem of the existence of the high peak-average power ratio.The main thesis reads as followsGive the development status quo of the underwater acoustic communication and the application of the status quo of OFDM technology in the acoustic communication field; simultaneously this thesis discusses the OFDM technique in detail and gives a generic OFDM system block diagram. The thesis has a deep analysis of high peak-average power ratio (PAPR) problem of OFDM system, and has make a series of the algorithms simulation to compare the merits of the scope of application of the algorithms. Through the above studies, the thesis has come up with a suitable algorithm for the practical application of engineering and feasible analysis algorithm.