Hi yes you are right, I can't understand it mathematically. According to this, I am asking a help from someone who knows it. I tried to find some files about LSP and I found only one paper and this paper also related to speech recognition. The code is shown in below:
function lsp=lpc_lsp(a)
p=length(a); A(1)=1; B(1)=1;
for k=2
A(k)=(a(k) - a(p+2-k)) + A(k-1);
B(k)=(a(k) + a(p+2-k)) - B(k-1);
end
r1=roots(A);
r2=roots(B);
for k=1
-1
if (real(r1(k)) < 0)
theta1(k)=pi-abs(atan(imag(r1(k))/real(r1(k))));
else
theta1(k)=abs(atan(imag(r1(k))/real(r1(k))));
end
if (real(r2(k)) < 0)
theta2(k)=pi-abs(atan(imag(r2(k))/real(r2(k))));
else
theta2(k)=abs(atan(imag(r2(k))/real(r2(k))));
end
end
p=p-1;
for k=1
/2
theta(k)=theta1(k*2);
theta(k+ round(p/2))=theta2(k*2);
end
lsp=sort(theta); %Sort into ascending order
This code was took from the following link : **broken link removed**
or it is shown the book which is named "Applied Speech and Audio Processing: With MATLAB Examples", 106-112 pages.
So, could you help to me to use this code or to explain it for me, please ?