摘要 |
<p>A method using the algebraic index CELP coding technique. The search for CELP excitation comprises calculating certain components of covariance matrix U = HT.H where H is a lower triangular Toeplitz matrix formed from the impulse response of a filter consisting of synthesis filters and a perceptual weighting filter. The stored covariance matrix components are only those of pattern U(pos¿i,p?,posi,p) and those of pattern U(posi,p,posj,q), where posi,p and posj,q are the i position and the j position respectively for pulses p and q in the algebraic index codes.</p> |