CONVERSION OF LINEAR PREDICTIVE COEFFICIENTS USING AUTO-REGRESSIVE EXTENSION OF CORRELATION COEFFICIENTS IN SUB-BAND AUDIO CODECS

摘要

Disclosed are systems and methods for the efficient conversion of linear predictive coefficients. This method is usable, for example, in the conversion of full band linear predictive coding ("LPC") coefficients to sub-band LPCs of a sub-band speech codec (200, 300). The sub-bands may or may not be down-sampled. In an embodiment, the LPC coefficients of the sub-bands are obtained (400) from the correlation coefficients, which are in turn obtained (402) by filtering the auto-regressive extended auto-correlation coefficients of the full band LPCs. The method also allows the generation of an LPC approximation of a pole-zero weighted synthesis filter.