Higher-Order Spectra (Including Bispectrum) Analysis in MATLAB

MATLAB implementation of higher-order spectra analysis, including bispectrum computation, provides both direct and indirect methods suitable for signal detection, time-delay estimation, and spectral analysis applications. Higher-order spectra represent a nonlinear signal analysis technique that extracts additional signal characteristics beyond conventional power spectrum analysis. The direct method involves computing higher-order moments directly from the signal data, typically implemented using MATLAB's signal processing functions for cumulant calculation. The indirect method first estimates lower-order statistics before deriving higher-order spectra, offering computational efficiency advantages for large datasets. In signal processing and communications domains, higher-order spectral analysis plays a vital role in applications such as phase coupling detection, Gaussianity testing, and nonlinear system identification. Key MATLAB functions involved may include cumest, bispecd, and related spectral estimation tools from the Signal Processing Toolbox, enabling researchers to extract higher-order statistical features through appropriate windowing and segmentation techniques.