Distortionless demodulation of narrow-band single-sideband angle modulated signals

The problem of distortionless demodulation of a narrow-band single-sideband angle modulated signal is considered. The receiver uses a standard angle detector followed by a low-pass filter. The class of modulating signals is Zakai´s class of band-limited functions and processes. It is shown that the demodulation of these baseband signals is distortionless under an appropriate boundedness constraint on the signals.