What do you already know?

• What do most folks have experience with? AM/FM/TV $\rightarrow$ analog transmission.   
• What is the usual old-style model?
• How do we rate performance?
• Goodness of system $\equiv G(\hat{s}(t),s(t))$.
• Usually $\hat{s}(t)$ must be a ``faithful'' replica of s(t).
• Almost universal MEAN SQUARE ERROR (MSE) metric
$$G(\hat{s}(t),s(t))=\int \vert s(t) - \hat{s}(t)\vert^2 dt$$
 
 

• Subjective judgement:


But of course, phase shift means nothing to ears and the usual MSE bites the dust. Just remember Fourier expansion of odd square wave 1/(2k+1) applied to cosine waveforms. They sound the same!

1999-01-20