[ = E[s[n]s[n+k]] + E[s[n]w[n+k]] + E[w[n]s[n+k]] + E[w[n]w[n+k]] ]
[ \sum x[n] - N A = 0 \quad \Rightarrow \quad A = \frac1N \sum x[n] ] [ = E[s[n]s[n+k]] + E[s[n]w[n+k]] + E[w[n]s[n+k]] +
Typical chapters in such a book: