Suboptimal detection of non-Gaussian signals by third-order spectral analysis

The use of higher-order spectra (HOS) is proposed for improving detection performance in non-Gaussian signals. The method comprises two stages. First, the higher-order spectra of the received signal are estimated using conventional spectral estimation techniques; then, a (maximum) likelihood ratio test (LRT) is performed in the higher-order-spectra domain. It is shown that, under certain low signal-to-noise ratio (SNR) conditions, the HOS-based method performs much better than the conventional energy one. The required processor is derived and its performance is analyzed. While the method is demonstrated using the third-order spectrum (called bispectrum), it can easily be extended to higher-order analysis (e.g. trispectrum, etc.)