Patent ID: 8812307

Claim:
A Linear Prediction Coding (LPC) analysis method, wherein an input signal has 80 sample points x[n], n=0,1, . . . ,79, the method comprising: obtaining, by a LPC analysis apparatus, an amplitude value |x[0]| of the first sample point and an amplitude value |x[79]| of the last sample point of an input signal; determining, by the LPC analysis apparatus, whether the amplitude value |x[0]| of the first sample point is greater than or equal to a threshold, and whether the amplitude value |x[79]| of the last sample point is greater than or equal to the threshold; obtaining, by the LPC analysis apparatus, a windowed signal by applying a window function w(n), n=0,1, . . . ,79 respectively on each of the sample points of the input signal; and processing, by the LPC analysis apparatus, the windowed signal to obtain an LPC coefficient for linear prediction; wherein when the amplitude value |x[0]| of the first sample point is greater than or equal to the threshold, the first eight points of the window function are set as w ( n )=0.16+0.84·cos(2·π·(31−4 ·n )/127), n= 0,1, . . . ,7; or when the amplitude value |x[0]| of the first sample point is smaller than the threshold, the first eight points of the window function are set as w ( n )=0.26+0.74·cos(2·π·(31−4 ·n )/127), n= 0,1, . . . ,7; the 9th to 72nd points of the window function are set as w(n)=1, n=8,9, . . . ,71; when the amplitude value |x[79]| of the last sample point is greater than or equal to the threshold, the last eight points of the window function are set as w ( n )=0.16+0.84·cos(2·π·(4 ·n− 285)/127), n= 72,73, . . . ,79; or when the amplitude value |x[79]| of the last sample point is smaller than the threshold, the last eight points of the window function are set as w ( n )=0.26+0.74·cos(2·π(4 ·n− 285)/127), n = 72,73, . . . ,79.