PITCH ESTIMATOR, PITCH ESTIMATION METHOD, SELF-CORRELATION COMPUTING DEVICE, AND SELF-CORRELATION COMPUTATION METHOD

摘要

PPROBLEM TO BE SOLVED: To detect a pitch period of a signal of discrete value system with less computation amount. PSOLUTION: A pitch estimator has a self-correlation computation unit which computes a self-correlation coefficient Corr(n, k) for a time difference k of a signal X(n) of discrete value system; and a maximum value detection means which detects, as a pitch period, a time difference which gives a maximum value from among the absolute values of a plurality of self-correlation coefficients Corr(n, k) which are different in time difference k, from the self-correlation coefficients Corr(n, k). The self-correlation computation device has a binary value encoding means which converts the signal X(n) to one bit signal XSBbin/SB(n), which conforms to a value below an intermediate value in its dynamic range or to the intermediate value or a value over the intermediate value; and a computation means which computes a self-correlation value of the one bit signal XSBbin/SB(n) and outputs it as a self-correlation coefficient Corr(n, k). PCOPYRIGHT: (C)2008,JPO&INPIT