www.gusucode.com > signal 案例源码程序 matlab代码 > signal/BandwidthExpansionOfLPCSpeechSpectrumExample.m

    %% Bandwidth Expansion of LPC Speech Spectrum
% Load a speech signal sampled at $F_s=7418\;\rm Hz$. The file contains a
% recording of a female voice saying the word "MATLAB(R)."

load mtlb

%%
% Model a 100-sample section of the signal using a 12th-order
% autoregressive polynomial.

Ao = lpc(mtlb(1000:1100),12);
Ax = polyscale(Ao,0.85);

%%
% Perform bandwidth expansion of the signal by scaling the roots of the
% autoregressive polynomial by 0.85. Plot the zeros, poles, and frequency
% responses of the models.

subplot(2,2,1)
zplane(1,Ao)
title('Original')

subplot(2,2,3)
zplane(1,Ax)
title('Flattened')

subplot(1,2,2)
[ho,w] = freqz(1,Ao);
[hx,w] = freqz(1,Ax);
plot(w/pi,abs([ho hx]))
legend('Original','Flattened')