FFT實現(xiàn)長序列卷積，256點

FIR濾波器

-------------------------------------------------------Code-------------------------------------------------------------

clear;

clc;

[y,fs]=audioread('C:\Users\shinelon\Documents\錄音\number2.wav');

figure

plot(y);

y = y(:, 1)';

for?i=0:1:1158

%sound(y,fs);

y_temp=y((i*256+1):1:(i+1)*256);

S=fft(y_temp,256);

%figure

%subplot(2,1,1);

%plot(y);

%title('原語音信號波形');

%subplot(2,1,2);

%plot(abs(S));

%title('原語音信號頻譜');

?

Hd = FIR1;

female_freq = filter(Hd,S);

%figure(2);

%subplot(2,1,1);

%plot(abs(female_freq));

%title('轉(zhuǎn)化后語音信號頻譜');

????if?i==0

???????female = real(ifft(female_freq,256))';

????else

????????temp = real(ifft(female_freq,256))';

????????female =[female;temp];

????end

end

figure(2);

plot(female);

audiowrite('C:\Users\shinelon\Documents\錄音\transform.wav',female*100,fs);

?

?

?

?

?

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function?Hd = FIR1

%FIR1 Returns a discrete-time filter object.

?

% MATLAB Code

% Generated by MATLAB(R) 9.1 and the DSP System Toolbox 9.3.

% Generated on: 06-Nov-2022 23:42:27

?

% Equiripple Highpass filter designed using the FIRPM function.

?

% All frequency values are in Hz.

Fs = 48000; ?% Sampling Frequency

?

Fstop = 150; ????????????% Stopband Frequency

Fpass = 1000; ???????????% Passband Frequency

Dstop = 0.0001; ?????????% Stopband Attenuation

Dpass = 0.057501127785; ?% Passband Ripple

dens ?= 20; ?????????????% Density Factor

?

% Calculate the order from the parameters using FIRPMORD.

[N, Fo, Ao, W] = firpmord([Fstop, Fpass]/(Fs/2), [0 1], [Dstop, Dpass]);

?

% Calculate the coefficients using the FIRPM function.

b ?= firpm(N, Fo, Ao, W, {dens});

Hd = dfilt.dffir(b);

?

% [EOF]