Recursive autocorrelation computation for LPC analysis

A method for recursively calculating the autocorrelation functions for LPC analysis in a vocoder environment is developed theoretically and studied experimentally. The method has three specific advantages: (1) it requires very little memory for its implementation; (2) it is realized by a structure consisting of several identical modules; and (3) the effective window length may be changed without varying the structure. Experimental results showed the speech quality to be comparable to (but slightly superior to) that produced by an autocorrelation LPC using a Hanning window.