Effects of Phase Nonlinearities on Phase-Shift-Keyed Pseudonoise/Spread-Spectrum Communication Systems

The effective signal-to-noise ratio of a phase-shift-keyed pseudonoise/spread-spectrum signal passed through a communication link with phase nonlinearities
\varphi(f)
is shown to be a fraction
\langlecos \varphi(f)\rangle^{2}
of the actual ratio, where
\langle \dot \rangle
denotes an average formed by weighting
cos \varphi(f)
by signal spectral power density across the passband.