A key area of research for wireless transmission is underwater communications

where acoustic signals are currently the best candidates for underwater communications. Orthogonal Frequency Division Multiplexing（OFDM）technique facilitates high data rate transmission over Underwater Acoustic（UWA） channels. In this paper

the UWA trust

in a communication channel is proposed based on the Fractional Fourier Transform（FRFT） of OFDM system. According to various conditions with the traditional OFDM systems

the system performance is deeply investigated. The conditions include the number of subcarriers

the modulation scheme and the Doppler frequency. Finally

the results show that although the calculation order of FRFT is the same as that of Fast Fourier Transform（FFT）

the performance of FRFT-based OFDM systems is better than traditional OFDM systems in all multipath scenarios

which meets the requirement that the underwater acoustic channel has low system complexity and low power consumption.