Loading .gitignore +1 −0 Original line number Diff line number Diff line Loading @@ -3,3 +3,4 @@ LAB3/~$b3+袁通+代育津+11810818+11910114.docx .DS_Store *.code-workspace LAB4/~$！实验报告格式说明 (1) copy.docx LAB3/P3_10_a.m LAB3/P3_8_b.m +1 −1 Original line number Diff line number Diff line Loading @@ -18,4 +18,4 @@ ylabel('H2(e^{j\omega} )'); title('frequency responses of Systems 2'); saveas(gcf, "plots/P3_8_b_out.png"); close; %close; LAB5/C_01_01.wav 0 → 100644 +102 KiB File added.No diff preview for this file type. View file LAB5/C_01_02.wav 0 → 100644 +57.9 KiB File added.No diff preview for this file type. View file LAB5/lab5.m 0 → 100644 +69 −0 Original line number Diff line number Diff line %5.1 [y1,fs]=audioread('C_01_01.wav'); y1=y1'; %sound(y,fs); sig=repmat(y1,1,10); N = length(y1); noise=1-2*rand(1,N); [Pxx,w]=pwelch(sig,[],[],512,fs); figure(1); plot(w,Pxx); title('The power spectral density of the speech signal'); xlabel('w'); ylabel('Pxx'); b=fir2(3000,w/(fs/2),sqrt(Pxx/max(Pxx))); [h,wh]=freqz(b,1,128); ssn=filter(b,1,noise); [Pxx1,w1]=pwelch(ssn,[],[],512,fs); figure(2); plot(w1,Pxx1); title('The power spectral density of the speech-shaped noise'); xlabel('w1'); ylabel('Pxx1'); %5.2 ssn=norm(y1)*ssn/10^(-5/20)/norm(ssn); snr=20*log10(norm(y1)/norm(ssn)); disp(snr); y=y1+ssn; y=y*norm(y1)/norm(y); %5.3 y=abs(y); figure(3); [b,a]=butter(2,100/(fs/2)); envelop3=filter(b,a,y); subplot(3,1,1); plot(envelop3); title('f_{cut}=100 Hz'); xlim([0,6000]); [b,a]=butter(2,200/(fs/2)); envelop2=filter(b,a,y); subplot(3,1,2); plot(envelop2); title('f_{cut}=200 Hz'); xlim([0,6000]); [b,a]=butter(2,300/(fs/2)); envelop3=filter(b,a,y); subplot(3,1,3); plot(envelop3); title('f_{cut}=300 Hz'); xlim([0,6000]); figure(4); [b,a]=butter(2,200/(fs/2)); envelop=filter(b,a,y); subplot(2,1,1); plot(envelop); title('2nd order'); xlim([0,6000]); [b,a]=butter(6,200/(fs/2)); envelop=filter(b,a,y); subplot(2,1,2); plot(envelop); title('6th order'); xlim([0,6000]); No newline at end of file Loading
.gitignore +1 −0 Original line number Diff line number Diff line Loading @@ -3,3 +3,4 @@ LAB3/~$b3+袁通+代育津+11810818+11910114.docx .DS_Store *.code-workspace LAB4/~$！实验报告格式说明 (1) copy.docx LAB3/P3_10_a.m
LAB3/P3_8_b.m +1 −1 Original line number Diff line number Diff line Loading @@ -18,4 +18,4 @@ ylabel('H2(e^{j\omega} )'); title('frequency responses of Systems 2'); saveas(gcf, "plots/P3_8_b_out.png"); close; %close;
LAB5/lab5.m 0 → 100644 +69 −0 Original line number Diff line number Diff line %5.1 [y1,fs]=audioread('C_01_01.wav'); y1=y1'; %sound(y,fs); sig=repmat(y1,1,10); N = length(y1); noise=1-2*rand(1,N); [Pxx,w]=pwelch(sig,[],[],512,fs); figure(1); plot(w,Pxx); title('The power spectral density of the speech signal'); xlabel('w'); ylabel('Pxx'); b=fir2(3000,w/(fs/2),sqrt(Pxx/max(Pxx))); [h,wh]=freqz(b,1,128); ssn=filter(b,1,noise); [Pxx1,w1]=pwelch(ssn,[],[],512,fs); figure(2); plot(w1,Pxx1); title('The power spectral density of the speech-shaped noise'); xlabel('w1'); ylabel('Pxx1'); %5.2 ssn=norm(y1)*ssn/10^(-5/20)/norm(ssn); snr=20*log10(norm(y1)/norm(ssn)); disp(snr); y=y1+ssn; y=y*norm(y1)/norm(y); %5.3 y=abs(y); figure(3); [b,a]=butter(2,100/(fs/2)); envelop3=filter(b,a,y); subplot(3,1,1); plot(envelop3); title('f_{cut}=100 Hz'); xlim([0,6000]); [b,a]=butter(2,200/(fs/2)); envelop2=filter(b,a,y); subplot(3,1,2); plot(envelop2); title('f_{cut}=200 Hz'); xlim([0,6000]); [b,a]=butter(2,300/(fs/2)); envelop3=filter(b,a,y); subplot(3,1,3); plot(envelop3); title('f_{cut}=300 Hz'); xlim([0,6000]); figure(4); [b,a]=butter(2,200/(fs/2)); envelop=filter(b,a,y); subplot(2,1,1); plot(envelop); title('2nd order'); xlim([0,6000]); [b,a]=butter(6,200/(fs/2)); envelop=filter(b,a,y); subplot(2,1,2); plot(envelop); title('6th order'); xlim([0,6000]); No newline at end of file
