Two components of linear distortion produced by transmitting asignal through an LTI (linear time invariant) system:
Amplitude distortion - the frequency components of the input signalare transmitted through the system with different amounts of gainor attenuation.
Phase distortion - the phase response is not linear with frequency inside the frequency band of interest. Different frequency components are subject to different delay in passing through the system.
Multipath propagation model: y[n] = x[n] + ax[n-1].
In general, the parameter a can be real or complex, so long as |a|< 1.
What form of linear distortion is introduced by this channel?