The periodicity is a feature of science and engineering phenomena

so detecting periodicity from complex and noise-included samples and measuring its parameters are important topics in signal processing.Spectral correlation is a useful tool to find second-order periodicity of cyclostationary signals.This paper investigates the reasons

procedures and features using spectral correlation to analyze cyclicity.First

internal relations between main definitions in spectral correlation theory are summarized and mathematic diagrams reflecting their transforming or mapping relations are built.Then a method to calculate spectral correlation based on the diagrams is proposed.By analysis of single periodic signals and connections between periods and results in each operation

physical functions of cyclic autocorrelation

spectral correlation

limit periodic spectrum and cyclic frequency

etc

are interpreted.