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About Mean-removed LSF vector and quantization of LSF coefficient in CELP coding

Started by cherrymata November 12, 2003
Dear All,

I have some difficulties in understanding CELP coding process,
one of them is about Mean-removed LSF vector and quantization of LSF
coefficient (ETSI 06.09).

For 7.95 kbps mode, the residual LSF is quantified using split vector
quantization (SVQ). The residual LSF is given by:
r(n)=z(n)- p(n)
where z(n) denote the mean-removed LSF vector at frame n. What is the
meaning of mean-removed LSF and how do you calculate it?

and then after we split the residual vector, do we have to apply the
shannon theorem or do we only need to apply uniform quantization to
each splitted residual vector?

I hope someone can help me... ;)
thanks before

regards,
arida