Convert line spectral frequencies to prediction filter coefficients
a = lsf2poly(lsf)
a = lsf2poly(lsf) returns a vector a containing the prediction filter coefficients from the vector lsf of line spectral frequencies. If lsf is a matrix of size MxN with separate channels of line spectral frequencies in each column, the returned a matrix has the resulting prediction filter coefficients in rows and is of size Nx(M+1).
lsf = [0.7842 1.5605 1.8776 1.8984 2.3593]; a = lsf2poly(lsf) a = 1.0000 0.6148 0.9899 0.0001 0.0031 -0.0081
 Deller, J.R., J.G. Proakis, and J.H.L. Hansen, Discrete-Time Processing of Speech Signals, Prentice-Hall, 1993.
 Rabiner, L.R., and R.W. Schafer, Digital Processing of Speech Signals, Prentice-Hall, 1978.