Reply by Peter K. November 30, 20052005-11-30
John wrote:

> I am trying to do some statistics, but I don't know how to solve the problem > I am working on. > > I have N speech segments and I perform a 10th order LPC-analysis of each > segment and get a 10-dimensional LPC-vector A(j)=[a1(j),a2(j),....a10(j)] > for j=1 to N. > > I then convert all A(j) to B(j)=[c1(j),c2(j),......,c10(j)] where the > coefficients of B(j) are the LSF-coefficients corresponding to the > LPC-vector A(j). > > I want to figure out what: > > - the probability of B(j) given B(j-1) is ? (transition probability) > - the probability of B(j) ? > > How do I do that?
1. Calculate Pr[ B(j) | B(j-1) ]. 2. Calculate Pr[ B(j) ] = sum{k = 0 to N-1} Pr[ B(j) | B(k) ]
> My thoughts: > The first step would be to define a discrete space S of outcomes for B(j), > but the number of possible outcomes is very large. The coefficients of B(j) > each > have a dynamic range from 0 to pi. If I use a discrete range from > 0,0.01,0.02,..........,3.14 that is 315 possible outcomes for any > coefficient in B(j). Since B(j) is a 10-dimensional > vector I have 315^10 possible outcomes in the space S. That number is way > too big to do any realistic computation in matlab......
Don't quantize nearly so finely and use vector quantization rather than quantizing the individual elements. Ciao, Peter K.
Reply by John November 30, 20052005-11-30
Hi

I am trying to do some statistics, but I don't know how to solve the problem 
I am working on.

I have N speech segments and I perform a 10th order LPC-analysis of each 
segment and get a 10-dimensional LPC-vector A(j)=[a1(j),a2(j),....a10(j)] 
for j=1 to N.

I then convert all A(j) to B(j)=[c1(j),c2(j),......,c10(j)] where the 
coefficients of B(j) are the LSF-coefficients corresponding to the 
LPC-vector A(j).

I want to figure out what:

- the probability of B(j) given B(j-1) is ? (transition probability)
- the probability of B(j) ?

How do I do that?

My thoughts:
The first step would be to define a discrete space S of outcomes for B(j), 
but the number of possible outcomes is very large. The coefficients of B(j) 
each
have a dynamic range from 0 to pi. If I use a discrete range from 
0,0.01,0.02,..........,3.14 that is 315 possible outcomes for any 
coefficient in B(j). Since B(j) is a 10-dimensional
vector I have 315^10 possible outcomes in the space S. That number is way 
too big to do any realistic computation in matlab......