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This commit is contained in:
Silas Oettinghaus
2024-04-19 10:31:36 +02:00
parent 025498d120
commit ed17953407
30 changed files with 3261 additions and 1580 deletions
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195
Classes/02_etc/Filter.m
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@@ -1,4 +1,4 @@
classdef Filter
classdef Filter < handle
%FILTER Summary of this class goes here
% Detailed explanation goes here
@@ -12,7 +12,7 @@ classdef Filter
filtdegree
passband_ripple
stopband_ripple
fsamp
fs
w
end
@@ -24,7 +24,8 @@ classdef Filter
arguments
options.filterType filtertypes = filtertypes.bessel_inp ;
options.f_cutoff = 0;
options.fsamp = 0;
options.fs = 0;
options.signal_length = 0;
options.filtdegree = 3;
options.passband_ripple = 0.5;
options.stopband_ripple = 0.5;
@@ -36,7 +37,12 @@ classdef Filter
for n = 1:numel(fn)
obj.(fn{n}) = options.(fn{n});
end
% *Nur* wenn die beiden gegeben wurde, kann das Filter vorab
% erstellt werden - sonst zur Laufzeit
if obj.fs ~= 0 && obj.signal_length ~= 0
[obj.H,obj.w] = obj.buildFilter();
end
end
@@ -61,75 +67,77 @@ classdef Filter
end
function yout = process_(obj,xin)
obj.signal_length = length(xin);
[obj.H,obj.w] = obj.buildFilter(obj.filterType);
if isempty(obj.H) || obj.signal_length ~= length(obj.H)
[obj.H,obj.w] = obj.buildFilter();
end
yout = obj.applyFilter(xin);
end
end
function y_filtered = applyFilter(obj,xin)
y_filtered = ifft(obj.H.*fft(xin));
end
function [H,w] = buildFilter(obj,filterType)
function [H,w] = buildFilter(obj)
w = [];
rp = obj.passband_ripple; %passband ripple
rs = obj.stopband_ripple; %stopband ripple
switch filterType
switch obj.filterType
case 1
% Bessel filter, impulse invariant transformed
[B, A] = besself(obj.filtdegree, 2*pi*obj.f_cutoff);
[B ,A] = impinvar(B,A,obj.fsamp);
[B ,A] = impinvar(B,A,obj.fs);
case 2
% Bessel filter, impulse bilinear transformed
[Z, P, K] = besself(obj.filtdegree, 2*pi*obj.f_cutoff);
[Z ,P, K] = bilinear(Z,P,K,obj.fsamp);
[Z ,P, K] = bilinear(Z,P,K,obj.fs);
[B ,A] = zp2tf(Z ,P ,K);
case 3
% Butterworth filter
if obj.lowpass == 1 %lowpass
[B, A] = butter(obj.filtdegree, obj.f_cutoff/(obj.fsamp/2),'low');
[B, A] = butter(obj.filtdegree, obj.f_cutoff/(obj.fs/2),'low');
else % highpass
[B, A] = butter(obj.filtdegree, obj.f_cutoff/(obj.fsamp/2),'high');
[B, A] = butter(obj.filtdegree, obj.f_cutoff/(obj.fs/2),'high');
end
case 4
% Chebyshev 1 filter
[B, A] = cheby1(obj.filtdegree,rp, obj.f_cutoff/(obj.fsamp/2));
[B, A] = cheby1(obj.filtdegree,rp, obj.f_cutoff/(obj.fs/2));
case 5
% Chebyshev 2 filter
[B, A] = cheby2(obj.filtdegree,rs, obj.f_cutoff/(obj.fsamp/2));
[B, A] = cheby2(obj.filtdegree,rs, obj.f_cutoff/(obj.fs/2));
case 6
% Elliptic filter
[B, A] = ellip(obj.filtdegree,rp,rs,obj.f_cutoff/(obj.fsamp/2));
[B, A] = ellip(obj.filtdegree,rp,rs,obj.f_cutoff/(obj.fs/2));
case 7
% Hamming filter
g=(obj.filtdegree-1)/2;
wc=obj.f_cutoff/(obj.fsamp/2);
wc=obj.f_cutoff/(obj.fs/2);
B = wc*sinc(wc*(-g:g)).*hamming(obj.filtdegree)';
A=1;
@@ -137,7 +145,7 @@ classdef Filter
% Raised Cosine filter
B = firrcos(obj.filtdegree,obj.f_cutoff,para.df,obj.fsamp);
B = firrcos(obj.filtdegree,obj.f_cutoff,df,obj.fs);
A=1;
case 9
@@ -145,7 +153,7 @@ classdef Filter
% Sinc filter
g=(obj.filtdegree-1)/2;
wc=obj.f_cutoff/(obj.fsamp/2);
wc=obj.f_cutoff/(obj.fs/2);
B = wc*sinc(wc*(-g:g));
A=1;
@@ -155,55 +163,122 @@ classdef Filter
%check if order ist multiple of 1/2
blocklen=obj.signal_length;
faxis=linspace(-obj.fsamp/2,obj.fsamp/2,blocklen+1)';%generates arow vector faxis of blocklen+1 points linearly spaced between and including -para.fs/2 and para.fs/2
faxis=linspace(-obj.fs/2,obj.fs/2,blocklen+1)';%generates arow vector faxis of blocklen+1 points linearly spaced between and including -fs/2 and fs/2
faxis=ifftshift(faxis(1:end-1));
H=exp(-((faxis)/(obj.f_cutoff*2)).^(2*obj.filtdegree)*log(2)*2^(2*obj.filtdegree-1));
% figure()
% hold on
% xline(obj.f_cutoff*1e-9,'LineWidth',3,LineStyle='--');
% xline(-obj.f_cutoff*1e-9,'LineWidth',3,LineStyle='--');
% plot(faxis*1e-9,20*log10(abs(H)),'LineWidth',3);
% ax = gca;
% ylim([-6 0])
% grid on
% xlabel('Freq in GHz')
% ylabel('Magnitude (dB)')
end
% Build Filter from coefficients
if filterType ~= 10
if obj.filterType ~= 10
[H,w] = freqz(B, A, obj.signal_length,'whole');
% figure()
% hold on
% plot(w/(2*pi)*obj.fsamp*1e-9,20*log10(abs(H)),'LineWidth',3);
% ax = gca;
% %ylim([-6 0])
% grid on
% xlabel('Freq in GHz')
% ylabel('Magnitude (dB)')
% figure(30)
% freqz(B, A, 2048, obj.fsamp);
% hfvt = fvtool(B,A);
end
end
function show(obj)
obj.signal_length = 1024;
[H,w] = obj.buildFilter(obj.filterType);
plot(w/pi,20*log10(abs(H)));
ax = gca;
ax.XTick = 0:.5:2;
grid on
xlabel('Normalized Frequency (\times\pi rad/sample)')
ylabel('Magnitude (dB)')
%freqz(H);
obj.signal_length = 512;
[H_,~] = obj.buildFilter();
figure()
sgtitle('- Filter Visualization -','FontSize',11)
hold on
fs = obj.fs;
frex = linspace(-fs/2,fs/2,numel(H_)).*1e-9;
filt = fftshift(20*log10(abs(H_)));
filt_angle = fftshift(angle(H_));
filt_grpdly = diff(unwrap(filt_angle))./diff(frex.');
fc = obj.f_cutoff;
fcut_= [-fc*1e-9;fc*1e-9];
[~, index] = min(abs(filt - (-3)));
threedB = frex(index);
cur_module_name = '';
filter_desc = char([num2str(obj.filtdegree),'th-order ',char(obj.filterType),'; f cut:',num2str(fc.*1e-9),' GHz']);
legend Interpreter none
subplot(3,1,1);
legend Interpreter none
title('Magnitude')
hold on
p = plot(frex,filt,'LineWidth',1,'LineStyle','-','DisplayName',[cur_module_name,': ',filter_desc]);
xline([-threedB,threedB],'LineStyle','-','LineWidth',1,'HandleVisibility','off','Color',p.Color);
xline(fcut_,'LineStyle',':','LineWidth',1,'HandleVisibility','off','Color',p.Color);
yline(-3,'LineStyle',':','LineWidth',1,'HandleVisibility','off');
ylim([-10 0])
xlim([-200 200])
ylabel('Magnitude (dB)')
legend
subplot(3,1,2);
legend Interpreter none
title('Phase')
hold on
p = plot(frex,filt_angle,'LineWidth',1,'Color',p.Color,'LineStyle',':','DisplayName',[cur_module_name,': ',filter_desc]);
ylim([-pi,pi]);
yticks([-pi, 0, pi]);
yticklabels({'-$\pi$', '0', '$\pi$'});
ylabel('Angle (rad)');
subplot(3,1,3);
legend Interpreter none
title('Group Delay')
hold on
p = plot(frex(2:end),filt_grpdly,'LineWidth',1,'Color',p.Color,'LineStyle',':','DisplayName',[cur_module_name,': ',filter_desc]);
ylabel('Angle (rad)');
ax = gca;
xlim([-200 200])
grid on
xlabel('Freq in GHz')
legend
end
function showHere(obj)
obj.signal_length = 512;
[H_,~] = obj.buildFilter();
fs = obj.fs;
frex = linspace(-fs/2,fs/2,numel(H_)).*1e-9;
filt = fftshift(20*log10(abs(H_)));
filt_angle = fftshift(angle(H_));
filt_grpdly = diff(unwrap(filt_angle))./diff(frex.');
fc = obj.f_cutoff;
fcut_= [-fc*1e-9;fc*1e-9];
[~, index] = min(abs(filt - (-3)));
threedB = frex(index);
cur_module_name = '';
filter_desc = char([num2str(obj.filtdegree),'th-order ',char(obj.filterType),'; f cut:',num2str(fc.*1e-9),' GHz']);
legend Interpreter none
legend Interpreter none
title('Magnitude')
hold on
p = plot(frex,filt,'LineWidth',1,'LineStyle','-','DisplayName',[cur_module_name,': ',filter_desc]);
xline([-threedB,threedB],'LineStyle','-','LineWidth',1,'HandleVisibility','off','Color',p.Color);
xline(fcut_,'LineStyle',':','LineWidth',1,'HandleVisibility','off','Color',p.Color);
yline(-3,'LineStyle',':','LineWidth',1,'HandleVisibility','off');
legend
end
end
end