where and M ( t ) is a WSS process independent of .. Here the modulation process translates the spectrum of M ( t ) from base-band to a band centred around

• The noise associated with communication signal undergoes band-pass filtering in the communication receiver and the band-pass filtered noise can be modeled as a band-pass process.

 Figure 1 illustrates the power spectrum of a bandpass random process.

Figure 1 Power spectrum of a band-pass random process