Fig. 2.12. The Dirichlet Kernel Function [wo(o) = Dyy(6)]. 
2. | Wn(%) dp =1,1.e., w(0) = 1 from Eq. 2.92, to keep R(0) unchanged. 
3. | Wi(@) dp < ©, to make Sw) a consistent estimator. 
4s L——.. »» 
4. Wn?) > 0, uniformly as N > ~, 
Namo 
Irt\ 2 
= |w (r) 
5. Ee — 0 as N— ©, to ensure that Wy(@) is not too narrow in relation 
> wr 
1 i i : ; 
to (=) and to have s(w) an asymptotically unbiased estimator of s(w). 
The effects of the spectral windows, most of them designed under the above 
conditions, can be summarized as follows: 
1. Bias, that was 0 for the estimator “‘Periodogram Py(w),” is now 
32 
