fig6_16.m

数字信号处理Matlab演示文件,其中各个文件加放置了不同的matlab子文件

% QUANTISE.M: Effects of coefficient quantisation on FIR LP filter
% (JST 27/7/00)
% revised: 10/8/01
%
% Copyright Notice -
%
%       This software, and the comments, are the property of
%       The University of Edinburgh, and must be used only for
%       educational purposes.
%

% Set up ideal filter and 16/12/8 bit quantisation

B1=fir1(62,0.2);
[P1,f] = freqz(B1,1,512,1);
B2 = round(B1*32767/B1(32))/(32767/B1(32));
P2 = freqz(B2,1,512,1);
B3 = round(B1*2047/B1(32))/(2047/B1(32));
P3 = freqz(B3,1,512,1);
B4 = round(B1*127/B1(32))/(127/B1(32));
P4 = freqz(B4,1,512,1);

% Plot Filter Frequency response

plot(f,20*log10(abs(P1))),axis([0 0.5 -90 0]),xlabel('Normalised Frequency','Fontsize',12), ylabel('Power (dB)','Fontsize',12),title('Frequency Response of FIR Filter using Hamming Window','Fontsize',12);
fprintf(1,'Press return to continue');
pause;
plot(f,20*log10(abs(P2))),axis([0 0.5 -90 0]),xlabel('Normalised Frequency','Fontsize',12), ylabel('Power (dB)','Fontsize',12),title('Frequency Response of 16 bit FIR Filter','Fontsize',12);
fprintf(1,'Press return to continue');
pause;
plot(f,20*log10(abs(P3))),axis([0 0.5 -90 0]),xlabel('Normalised Frequency','Fontsize',12), ylabel('Power (dB)','Fontsize',12),title('Frequency Response of 12 bit FIR Filter','Fontsize',12);
fprintf(1,'Press return to continue');
pause;
plot(f,20*log10(abs(P4))),axis([0 0.5 -90 0]),xlabel('Normalised Frequency','Fontsize',12), ylabel('Power (dB)','Fontsize',12),title('Frequency Response of 8 bit FIR Filter','Fontsize',12);
fprintf(1,'Press return to continue');
pause;
plot(f,20*log10(abs(P1)),f,20*log10(abs(P4))),axis([0 0.5 -90 0]),xlabel('Normalised Frequency','Fontsize',12), ylabel('Power (dB)','Fontsize',12),title('Comparison of Ideal FIR and 8 bit FIR Filter','Fontsize',12);