Demodulation of a phase-modulated noise carder

In this paper, an analysis is made of a communication system in which the information-bearing signal phase modulates a Gaussian noise carrier. The effect of additive Gaussian noise and linear filtering on the first-order statistics of the receiver output noise and on the character of the output signal are determined. It is shown that with regard to determining the distortion of the output signal, the system may be replaced by a single linear filter whose input is the modulated signal impressed on a sinusoidal rather than noise carrier. In this way, conventional FM techniques may be used for the determination of signal distortion.