Dinei A. Florencio
The behavior of several windows in relation to time delay
and spectral estimation is analyzed in its application
to CELP coders, with emphasis on time delay considerations.
From the data, the importance of Asymmetric
Windows in such context becomes evident. In
order to get objective conclusions, we have used a perceptually
weighted residual energy as the comparison
criteria. It is shown that a reduction in delay of up to 8
ms can be obtained with no penalty in quality, simply
with the correct choice of the window. Application to
the military CELP standard, and considerations about
the choice of asymmetric windows for other CELP implementations
are also included.