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imdd_silas/Classes/00_signals/Signal.m
Silas Oettinghaus 7c1d9850d6 updates of framework
- focus on AWG output power and lowpass characteristics
2024-04-26 14:08:21 +02:00

402 lines
11 KiB
Matlab

classdef Signal
%SIGNAL Summary of this class goes here
% Detailed explanation goes here
properties
signal
logbook
end
methods
function obj = Signal(signal)
%SIGNAL Construct an instance of this class
% Detailed explanation goes here
obj.signal = signal;
obj.signal = obj.signal;
SignalType = [];
TimeStamp = [];
Length = [];
SignalPower = [];
Nase = [];
Description = [];
obj.logbook = table(SignalType,TimeStamp,Length,SignalPower,Nase,Description);
end
%% CONVERT TO INFORMATIONSIGNAL
function [i_sig, varargout] = Informationsignal(obj,options)
arguments
obj
options.fs
options.logbook
end
if isa(obj,'Electricalsignal')
%convert to information
varargout{1} = obj.fs;
i_sig = Informationsignal(obj.signal,"fs",options.fs,"logbook",options.logbook);
elseif isa(obj,'Opticalsignal')
error("Cannot convert from optical- to informationsignal. Use O/E conversion first.");
end
end
%% CONVERT TO Electricalsignal
function [e_sig, varargout] = Electricalsignal(obj,options)
arguments
obj
options.fs
options.logbook
end
obj.logbook = options.logbook;
if isa(obj,'Opticalsignal')
%convert to electrical
varargout{1} = obj.nase;
varargout{2} = obj.lambda;
e_sig = Electricalsignal(obj.signal,"fs",obj.fs,"logbook",obj.logbook);
elseif isa(obj,'Informationsignal')
try
% specify fs at varargin{1}
e_sig = Electricalsignal(obj.signal,"fs",options.fs,"logbook",options.logbook);
catch
error("Signal Conversion failed [I -> E] ");
end
end
end
%% CONVERT TO Opticalsignal
function o_sig = Opticalsignal(obj, options)
arguments
obj
options.fs
options.logbook
options.nase
options.lambda
end
fn = fieldnames(options);
for l = 1:numel(fn)
try
obj.(fn{l}) = options.(fn{l});
end
end
if isa(obj,'Electricalsignal')
%convert to optical
o_sig = Opticalsignal(obj.signal,"fs",obj.fs,"lambda",options.lambda,"logbook",obj.logbook,"nase",options.nase);
elseif isa(obj,'Informationsignal')
error("Cannot convert from information- to opticalsignal. Use E/O conversion first.");
end
end
%% Add signals from one signal to another, the first object will sustain
function Sum = plus(X,y)
if isa(y,'Signal')
Sum = X;
Sum.signal = X.signal + y.signal;
elseif isnumeric(y)
Sum = X;
Sum.signal = X.signal + y;
end
end
function Product = times(X,y)
if isa(y,'Signal')
Product = X;
Product.signal = X.signal .* y.signal;
elseif isnumeric(y)
Product = X;
Product.signal = X.signal .* y;
end
end
%% Display length
function return_length = length(obj)
%METHOD1 Summary of this method goes here
% Detailed explanation goes here
return_length = length(obj.signal);
end
%% Write Logbook Entry
function obj = logbookentry(obj,varargin)
if nargin > 1
Description = varargin{1};
else
Description = "";
end
SignalType = [string(class(obj))];
TimeStamp = [(datetime('now','TimeZone','local','Format','HH:mm:ss'))];
Length = num2str(obj.length, ['%' sprintf('.%df', 0)]);%[obj.length];
SignalPower = [obj.power];
Nase = [0];
cell = {SignalType , TimeStamp , Length , SignalPower , Nase, Description};
obj.logbook = [obj.logbook;cell];
end
%% Resample Signal
function obj = resample(obj,options)
arguments
obj Signal
options.fs_in double
options.fs_out double
end
obj.signal = resample(obj.signal,options.fs_out,options.fs_in);
desc = ['resample signal from ', num2str(options.fs_in*1e-9), ' GHz to ', num2str(options.fs_out*1e-9), ' GHz' ];
obj = obj.logbookentry(desc);
obj.fs = options.fs_out;
end
%%
function spectrum(obj,fsamp,options)
arguments
obj
fsamp
options.figurename = [];
options.displayname = [];
end
%Get figure if there is already a spectrum plot -> I want to add the new
%spectum "onto" the existing plot to have a better comparison
if isempty(options.figurename)
fig = findall(groot, 'Type', 'figure', 'Name', 'power density');
if isvalid(fig)
fig = get(fig);
ax = gca;
hold on
else
figure('name','power density');
ax = gca;
end
else
fig = findall(groot, 'Type', 'figure', 'Name', options.figurename);
if isvalid(fig)
ax = fig.CurrentAxes;
hold on
else
figure('name',options.figurename);
ax = gca;
hold on
end
end
%compute FFT of input
Fsignal = fft(obj.signal);
%POWER spectral density (todo: toggle?)
psd = Fsignal.*conj(Fsignal);
%Use only magnitude of FFT (which was complex)
psd = abs(psd);
%Shift the spectrum to yield
psd = fftshift(psd);
%divide by N
psd = psd/length(Fsignal);
%smoothing
psd = smooth(psd,1000);
psd_plot = 20*log10(psd);
psd_plot(psd_plot<-120) = -120;
testParseval = 1;
if testParseval == 1
E_FreqDomain = sum(psd);
%test parseval
E_TimeDomain = sum(abs(Fsignal.^2));
if isequal(round(E_FreqDomain,1),round(E_TimeDomain,1))
%disp('Parseval is right!');
else
disp('Parseval theorem is not right...');
end
end
if fsamp <= 1e+100
%Frequency Axis
freq_vec = linspace(-fsamp/2,fsamp/2,length(psd));
freq_vec = reshape(freq_vec,size(psd_plot));
if ~isempty(options.displayname)
plot(freq_vec*1e-9,psd_plot,'Linewidth',0.5,'DisplayName',options.displayname,'Parent',ax);
else
plot(freq_vec*1e-9,psd_plot,'Linewidth',0.5,'Parent',ax);
end
xlabel('Frequency [GHz]')
else
%Wavelength Axis
freq_vec = physconst('LightSpeed')*linspace(-fsamp/2,fsamp/2,length(psd))./((physconst('LightSpeed')/1550e-9)^2);
if ~isempty(options.displayname)
plot(freq_vec*1e9,psd_plot,'Linewidth',0.5,'DisplayName',options.displayname,'Parent',ax);
else
plot(freq_vec*1e9,psd_plot,'Linewidth',0.5,'Parent',ax);
end
xlabel('Wavelength [nm]')
end
ylabel('Magnitude [dB]')
legend
grid minor;
end
%%
function obj = normalize(obj,options)
arguments
obj Signal
options.mode normalization_mode = normalization_mode.rms
end
switch options.mode
case normalization_mode.rms
obj.signal = obj.signal/sqrt(mean(abs(obj.signal).^2,"all"));
case normalization_mode.oneone
obj.signal = obj.signal - min(obj.signal);
obj.signal = obj.signal/max(abs(obj.signal));
obj.signal = (2*obj.signal) - 1;
end
end
%%
function [obj,delay_n] = delay(obj,options)
arguments
obj Signal
options.delay_samples = 0
end
obj.signal=delayseq(obj.signal,options.delay_samples);
end
%%
function [obj,D,cuts] = tsynch(obj,options)
% time sync and cut
arguments
obj Signal
options.reference Signal
options.fs_ref = 0;
end
%normalize the signal
a = obj.normalize("mode","oneone").signal;
%resample the reference
q = obj.fs/options.fs_ref;
b = options.reference.resample("fs_in",options.fs_ref,"fs_out",obj.fs).normalize("mode","oneone").signal;
%estimate delay between signals
[co,lags] = xcorr(a,b,100);
[~,pos] = max(co);
D = lags(pos);
if D == 100
warning('Check Sync: Delay is found to be 100 which is the max. windowlength is xcorr function!')
end
% delay by lagging samples
obj = obj.delay("delay_samples",-D);
cuts = obj.length-(options.reference.length*q);
if cuts > 10
warning('Check Sync: Signal difference larger than 10.')
end
if cuts < 0
% warning('Check Sync: Reference Signal shorter than signal to sync.')
else
% then cut out the length of the reference
obj.signal = obj.signal(1:end-cuts);
end
end
function eye(obj,fsym)
disp('h');
fsig = obj.fs;
q = fsig/fsym;
if q > 10 && isinteger(q)
sig = (obj.signal);
else
sig = (obj.resample("fs_in",fsig,"fs_out",fsym*30).signal);
q = 10;
end
figure()
clf
cursor = 200*q;
for s = 1:700
plot(sig(cursor-q:cursor+q),'Color','black','LineWidth',0.1,'LineStyle','-');
hold on
cursor=cursor+q;
s=s+1;
end
ylim([-3 3]);
end
end
end