In contrast, 8-psk modulation implements a linear mode in which a time-varying amplitude is output from the pa as measured by power versus time during the useful part of the burst.

This technique performs harmonic analysis of the nonspeech audio signals and then the resulted attributes including time-varying amplitude and frequency functions are piecewisely linearized.

The approach is to use short-time analysis to extract the characteristics of time-varying amplitude, frequency and phase in a digital modulation signal, and applies them for simple identification.