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regarding adaptive c/b in AMR encoder

Started by Sameer Kibey May 19, 2003
hi all

in the AMR standard, a signal called y[n] is used. it is the "filtered adaptive
codebook vector" and is defined as:
y[n] = v[n]*h[n] (read convolution of v[n] and h[n]), where
v[n] => adaptive codebook vector and
h[n] => impulse response of teh weighted synthesis filter.

i am unable to understand what y[n] actually represents. what is the need of
filtering the content of the adaptive codebook with the short term predictor?
can anyone please explain the significance of this signal y[n] ?

thanks
Sameer.



y[n] is needed to calculate the minimum error. y[n] is filtered
by h[n]-synthesis filter to get synthesised speech. The difference
of y[n] and original speech i.e error is what algorithm is trying
to minimize.

Hope this help.

Nayan Gaywala

--- In , "Sameer Kibey" <sameer@t...>
wrote:
> hi all
>
> in the AMR standard, a signal called y[n] is used. it is
the "filtered adaptive codebook vector" and is defined as:
> y[n] = v[n]*h[n] (read convolution of v[n] and h[n]), where
> v[n] => adaptive codebook vector and
> h[n] => impulse response of teh weighted synthesis filter.
>
> i am unable to understand what y[n] actually represents. what is
the need of filtering the content of the adaptive codebook with the
short term predictor? can anyone please explain the significance of
this signal y[n] ?
>
> thanks
> Sameer.