On line spectral frequencies
Willem Bastiaan Kleijn, Tom Bäckström, Paavo Alku · IEEE Signal Processing Letters · 2003
The commonly used line spectral frequencies form the roots of symmetric and antisymmetric polynomials constructed from a linear predictor. We provide a new, simpler proof that the symmetric and antisymmetric polynomials can be regarded as optimal constrained predictors that correspond to predicting from the low-pass and high-pass filtered signal, respectively.