Patent ID: 11972768
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A linear prediction analysis method of obtaining, in each frame, which is a predetermined time interval, linear prediction coefficients corresponding to an input time-series signal, the linear prediction analysis method comprising:
a step of receiving the input time-series signal, the time-series signal being a speech signal or an acoustic signal;
an autocorrelation calculation step of calculating an autocorrelation RO(i) between an input time-series signal XO(n) of a current frame and an input time-series signal XO(n−i) i samples before the input time-series signal XO(n) or an input time-series signal XO(n+i) samples after the input time-series signal XO(n), for each i of i=0, 1, . . . , Pmax at least; and
a prediction coefficient calculation step of calculating first-order to Pmax-order linear prediction coefficients, by using a modified autocorrelation R′O(i) obtained by multiplying a coefficient wO(i) by the autocorrelation RO(i) for each i,
wherein a case where, for at least part of each order i, the coefficient wO(i) corresponding to the order i is in a monotonically increasing relationship with an increase in a period, a quantized value of the period, an estimated value of the period or a value that is negatively correlated with a fundamental frequency based on the input time-series signal of the current frame or a past frame, is comprised, and
wherein the calculated first-order to Pmax-order linear prediction coefficients are used for encoding or analyzing the speech signal or the acoustic signal.