Method of calculating line spectral frequencies

摘要

In a method of encoding a source signal by determining Line Spectral Frequencies (LSFs) for representing Linear Predictive Coding (LPC) filter coefficients, real zeros are determined in associated polynomials P'' and Q'' in cos(momega), with each polynomial being a series of Chebyshev polynomials, a search for real zeroes being performed by evaluating the associated polynomials in a series of steps of a real variable u, an approximation of cos(momega) as a function of the real variable u being employed.