Fractional Bi-Spectrum
  A signal with discrete frequency components, has a zero bispectrum if no linear combination of the frequencies equals one of the frequency components. We introduce fractional bispectrum in which for such signals the fractional bispectrum is nonzero. It is shown that fractional bispectrum has the same property as bispectrum for Gaussian signals: the fractional bispectrum of a zero mean Gaussian signal is zero; therefore it can be used to eliminate or reduce the Gaussian noise. 
Mehrdad Abolbashari, Gelareh Babaie, Jonathan Babaie, and Faramarz   Farahi
stat.CO