An heterodyne method of measurement of the cross-spectral density and cross-correlation spectra of random processes

A model scheme Is examined for separate measurements of the magnitudes of the real and imaginary parts of the cross-spectral density of stationary coupled random processes. The use of heterodyne multiplication with preliminary filtering of the signals significantly simplifies the measuring scheme of the spectral characteristics. The use of hard clipping of the signals after preliminary filtering is considered, which leads to theoretical and technical advantages. In this work the exact characteristics of the described schemes are evaluated.