The effect of phase noise on noncoherent digital communications

The effect of oscillator phase noise on noncoherent data detection is considered with the objective of relating more specifically than in prior studies the phase noise key parameters (bandwidth, spectral slopes, upper and lower cutoffs, spectral height). The concentration is on binary frequency-shift keying (FSK) and differential phase-shift keying (DPSK). Expressions that relate decoding error probability to the phase noise spectra are derived. It is shown that decoding degradation can be accurately approximated by relatively simple integrals involving the phase noise structure function (the latter obtained directly from the phase spectrum). Examples with reported crystal and cesium oscillator noise are presented. The key phase noise parameters are the spectral bandwidth relative to the bit rate, and the gain level of the phase noise (the latter being dependent on the carrier frequency to which the oscillator is multiplied). Separate results are derived for FSK and DPSK, but the order of the degradation is comparable in both cases