Spectrum of the Sampled Signal: (contd:)
Alternatively, we follow a different derivation which can be easily extended to other periodic sampling structures.
First substitute equ (3.1.5) in to (3.1.2) and evaluate t1 and t2 at the sampling locations given by equ (3.1.1) to obtain,
After the change of variables
we have
Next break the integration over the  plane into a sum of integrals each over a square denoted by SQ  ,
where
SQ  is defined as,
 |
and |
|
|
