An analysis on fractional Fourier transform in Doppler and multipath mobile underwater acoustic channel.
Fractional Fourier transform is a kind of time‐frequency analysis method, which combines the information of signals in time domain and frequency domain. FRFT has chirp‐based decomposition characteristics, for a given chirp signal, there is a fraction which gathers the energy of linear frequency‐modulated signals to a maximum, which provides a basis for the detection of chirp signal with Doppler frequency offset and can also be used in the synchronization detection of mobile communication in underwater acoustic and the channel parameter estimation. This paper describes the theoretical basis of FRFT and its characteristics analysis, then by the computer simulation, performance analysis of FRFT and correlation detection in the conditions of Doppler and multipath are worked out, and the facts are verified that fractional Fourier transform is more suitable than copy correlator for Doppler frequency offset and multipath underwater acoustic channel.