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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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70
projects/IMDD_base_system/filter_debug.m Normal file
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clear
%% Set Simulation Variables
O = 18; %order of prbs
N = 2^(O-1); %length of prbs
[~,seed] = prbs(O,1); %initialize first seed of prbs
% Modulation
M = 4; %PAM-M
bitpattern = zeros(N,log2(M));
% Symbol Rate
fsym = 112e9;
% DAC Rate
fdac = 120e9;
% Simulation oversampling rate "k";
kover = 16;
% ADC Rate
fadc = 256e9;
% Simulation frequency in "analog domain"
fsimu = kover * fdac ;
%% CONSTRUCT ALL CLASSES
digimod = PAMmapper(M,0);
pulsef = Pulseformer("pulseform","rrc","fdac",fdac,"fsym",fsym,"pulselength",32,"rrcalpha",0.05);
awg = AWG('preset','M8199B','fdac',fdac,'kover',kover,'lpf_active',1,'f_cutoff',56e9,'lpf_type',filtertypes.gaussian,'bit_resolution',5.5);
lp_laser = Filter('filtdegree',1,"f_cutoff",30e9,"fsamp",fdac,"filterType",filtertypes.bessel_inp);
%% PROCESS
% PRBS Generation
for i = 1:log2(M)
[bitpattern(:,i),seed] = prbs(O,N,seed);
end
% Build Inf. signal class
bits = Informationsignal(bitpattern);
% Digi Mod
mod_out = digimod.map(bits);
% merken für EQ training
reference = mod_out;
% shape shape
mod_out = pulsef.process(mod_out);
test = applyPulseShaping(reference.signal,fsym,fdac);
% AWG -> ELECTRICAL DOMAIN
X = lp_laser.process(mod_out);
%X.spectrum(fsimu,"displayname",'AWG out','figurename','after AWG');

227
projects/IMDD_base_system/imddmodel.m Normal file
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function output = imddmodel(sir,dcmode)
for realiz = 1:3
rng(realiz);
%% Set Simulation Variables
delay = 0;10+(10*realiz); %mpi delay in meter
fiblen = 0; %main link in km
laser_linewidth =0e6;
O = 18; %order of prbs
N = 2^(O-1); %length of prbs
[~,seed] = prbs(O,1); %initialize first seed of prbs
% Modulation
M = 4; %PAM-M
bitpattern = zeros(N,log2(M));
% Symbol Rate
fsym = 112e9;
% DAC Rate
fdac = 120e9;
% Simulation oversampling rate "k";
kover = 16;
% ADC Rate
fadc = 256e9;
% Simulation frequency in "analog domain"
fsimu = kover * fdac ;
%% B) CONSTRUCT ALL CLASSES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
digimod = PAMmapper(M,0);
pulseform = Pulseformer("pulseform","rrc","fdac",fdac,"fsym",fsym,"pulselength",32,"rrcalpha",0.027);
awg = AWG('fdac',fdac,'kover',kover,'lpf_active',1,'f_cutoff',56e9,'lpf_type',filtertypes.gaussian,'bit_resolution',5.5);
lp_laser = Filter('filtdegree',1,"f_cutoff",50e9,"fsamp",fdac*kover,"filterType",filtertypes.bessel_inp);
u_pi = 3.5;
vbias = (0.5*u_pi)-u_pi;
extmodlaser = EML("mode",eml_mode.im_cosinus,"power",5,"fsimu",fsimu,"lambda",1550,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth);
fib = Fiber("fsimu",fdac*kover,"fiber_length",fiblen,"alpha",0.2,"D",16,"lambda0",thz2nm(193.1),"gamma",0);
reflectionpoint = Amplifier("amp_mode","ideal_no_noise","gain_mode","gain","amplification_db",sir);
reflectionprop = Fiber("fsimu",fdac*kover,"fiber_length",delay/1000,"alpha",0.2,"D",16,"lambda0",1550,"gamma",0);
opticatten = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",-8);
phdiode = Photodiode("fsimu",fdac*kover,"dark_current",2e-08,"responsivity",1,"temperature",20);
lp_diode = Filter('filtdegree',1,"f_cutoff",50e9,"fsamp",fdac*kover,"filterType",filtertypes.bessel_inp);
scp = Scope("fsimu",fdac*kover,"fadc",fadc,...
"delay",0,"fixed_delay",0,"lpf_bw",113e9,"filtertype",filtertypes.butterworth,...
"samplingdelay",0,"rand_samplingdelay",0,"freq_offset",0,"samp_jitter",0,...
"adcresolution",6,"quantbuffer",0.1,'block_dc',1);
eq = EQ("K",2,"plottrain",0,"plotfinal",0,...
"training_length",4096,"training_loops",2,...
"Ne",[50,5,3],"Nb",[3,2,2],...
"DCmu",0.05,"DDmu",[0.0004 0.0005 0.0006 0.0007 ],"DFEmu",0.005,"FFEmu",0.005,...
"dd_loops",2,"epsilon",[10 100 1000 ],"M",2,...
"thres",[0.005 0.004 0.0005 ],"l1act",0,"delay",0,"rho",0.0005,"ideal_dfe",0,"DB_aim",0);
eq2 = EQ_silas("Ne",[20,0,0],"Nb",[3,0,0],"trainlength",4096,"mu_dc_dd",0.005,"mu_dc_train",0.05,...
"mu_ffe_train",0.005,"mu_combined_dd",[0.0004 0.0006 0.0003 0.005],"ddloops",3,"dcmode",dcmode);
%% C) PROCESS TX %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 1) PRBS Generation
for i = 1:log2(M)
[bitpattern(:,i),seed] = prbs(O,N,seed);
end
% 2 ) Build Inf. signal class
bits = Informationsignal(bitpattern);
% 3) Digi modulation -> PAM-M signal
digimod_out = digimod.map(bits);
% 4) Pulse shaping -> racos
X = pulseform.process(digimod_out);
% 5) AWG (lowpass, quantization, sample and hold)
X = awg.process(X);
% 6) Lowpass behavior of laser and hf-cable? why twice?
X = lp_laser.process(X);
X = lp_laser.process(X);
% 7) Normalize signal
X = X.normalize("mode","oneone");
X.signal = X.signal .* 1.3800;
%% D) PROCESS OPTICAL CHANNEL %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 1) Laser; Modulation -> OPTICAL DOMAIN
[X,extmodlaser] = extmodlaser.process(X);
% 2) Main fiber propagation
X = fib.process(X);
if delay ~= 0
% 3) Reflection
% Reflection is just an attenuation
R = reflectionpoint.process(X);
% Propagate back and forth (actual fiber propagation)
R = reflectionprop.process(R);
% Delay the reflected signal
[R,n] = R.delay("delay_meter",delay);
% Add together
X.signal = X.signal(n:end);
R.signal = R.signal(n:end);
%disp(['SIR ',num2str(10*log10(X.power/R.power))]);
X = X+R;
% 4) Equalize
% cut reference signal to correct length (nessecary due to MPI delay)
digimod_out.signal = digimod_out.signal(round(n * fsym/fsimu) : end,:);
bitpattern = bitpattern(round(n * fsym/fsimu):end,:);
end
% 4) Attenuation
X = opticatten.process(X);
% X = edfaamp.process(X);
% 5) Photo Diode -> ELECTRICAL DOMAIN
X = phdiode.process(X);
X = lp_diode.process(X);
%% E) PROCESS RX %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 1) Oscilloscope (Sampling to f_adc; Quantization; Bandwidth Limitation)
X = scp.process(X);
% 2) Resample to 2x symbol rate
X = X.resample("fs_out",2*fsym,"fs_in",fadc);
% 3) Normalize
Eq_in = X.normalize("mode","rms");
% MPI reduction DC removal BEFORE EQ
wl = 3000; % symbols
Eq_in.signal = Eq_in.signal - 1/wl .* movsum( Eq_in.signal,[wl/2,wl/2]);
% Equalize Signal
[Eq_out] = eq2.process(Eq_in,digimod_out);
%% A1: MPI reduction DC removal
wl = 1000; % symbols
yk_dcsm = Eq_out;
yk_dcsm.signal = Eq_out.signal - 1/wl .* movsum( Eq_out.signal,[wl/2,wl/2]);
%% A2: MPI reduction Level wise error removal
yk_lvsm = Eq_out;
yk_lvlp = Eq_out;
pre_decision_level_uni = digimod.decide_pamlevel(Eq_out);
pre_decision_level_bi = ( pre_decision_level_uni*2-3 ) .* 1/sqrt(5);
e = Eq_out.signal - pre_decision_level_bi;
lp_mpi = Filter('filtdegree',1,"f_cutoff",2e6,"fsamp",fsym,"filterType",filtertypes.bessel_inp);
filtered = lp_mpi.process(e);
wl = 30; % symbols
smoothed = ( 1/wl .* movsum(e,[wl/2,wl/2]) );
% remove interference
for level = 0:3
yk_lvsm.signal(pre_decision_level_uni==level) = yk_lvsm.signal(pre_decision_level_uni==level) - smoothed(pre_decision_level_uni==level);
yk_lvlp.signal(pre_decision_level_uni==level) = yk_lvlp.signal(pre_decision_level_uni==level) - filtered(pre_decision_level_uni==level);
end
%% PROCESS RX %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 1) Digi Demod
d_bm = digimod.demap(Eq_out);
d_dcsm = digimod.demap(yk_dcsm);
d_lvsm = digimod.demap(yk_lvsm);
d_lvlp = digimod.demap(yk_lvlp);
% 2) BER
dbit = length(d_bm.signal)-length(bitpattern);
[~,errors_bm,ber_bm(realiz),loc] = calc_ber(d_bm.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",1);
[~,errors_dcsm,ber_dcsm(realiz)] = calc_ber(d_dcsm.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",0);
[~,errors_lvsm,ber_lvsm(realiz)] = calc_ber(d_lvsm.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",0);
[~,errors_lvlp,ber_lvlp(realiz)] = calc_ber(d_lvlp.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",0);
end
output.ber_bm = mean(ber_bm);
output.ber_dcsm = mean(ber_dcsm);
output.ber_lvsm = mean(ber_lvsm);
output.ber_lvlp = mean(ber_lvlp);
end

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projects/IMDD_base_system/run_loop.m Normal file
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clear
sir_loop = [-25:2:-13];
sir_loop = 0;
lw_loop = [1,2,3];
data = cell(length(sir_loop),length(lw_loop));
iterations=size(data);
parfor ix = 1:numel(data)
[u1,u2] = ind2sub(iterations,ix);
output = imddmodel(sir_loop(u1),lw_loop(u2));
data{ix} = output;
end
for sir = 1:size(data,1)
for lw = 1:size(data,2)
ber_bm(sir,lw) = data{sir,lw}.ber_bm;
ber_dcsm(sir,lw) = data{sir,lw}.ber_dcsm;
ber_lvsm(sir,lw) = data{sir,lw}.ber_lvsm;
ber_lvlp(sir,lw) = data{sir,lw}.ber_lvlp;
end
end
col = [ 0.6510 0.8078 0.8902
0.6980 0.8745 0.5412
0.9922 0.7490 0.4353];
figure(22)
for l = 1:numel(lw_loop)
hold on
plot(sir_loop,ber_bm(:,l),'DisplayName',['DC mode:', num2str(lw_loop(l)),', Linewidth= 50 MHz'],'Marker','o','MarkerFaceColor',col(l,:),'Color',col(l,:),'LineWidth',2,'LineStyle','--');
end
set(gca,'yscale','log');
yline(3.8e-3,'LineWidth',2,'LineStyle','--','HandleVisibility','off');
set(gca,'xdir','reverse');
%% Plot
col = linspecer(8);
figure(1)
hold on
m = ["x","o","pentagram","hexagram","*","+"];
cnt = 1;
for d = 1%:size(data,2)
for dc = 1:size(data,1)
for lw = 1:size(data,3)
ber_bm(dc,d,lw) = (data{dc,d,lw}.ber_bm);
ber_dcsm(dc,d,lw) = data{dc,d,lw}.ber_dcsm;
ber_lvsm(dc,d,lw) = data{dc,d,lw}.ber_lvsm;
ber_lvlp(dc,d,lw) = (data{dc,d,lw}.ber_lvlp);
end
end
i = 1;
comm_dn = [];% ['EQ DC Tap: ',num2str(dc_tap_loop(d)),' m'];
title("Dependency on Laser Linewidth; B2B; Delay : 2*50m")
plot(lw_loop*1e-6,mean(squeeze(ber_bm(1:end,d,:)),1),"LineWidth",1.2,"Marker",m(1),"MarkerSize",5,'Color',col(cnt,:),'DisplayName',[' ',comm_dn]);
plot(lw_loop*1e-6,mean(squeeze(ber_dcsm(1:end,d,:)),1),"LineWidth",1,"Marker",m(1+4),"MarkerSize",5,'LineStyle','--','Color',col(cnt,:),'DisplayName',['DC smoothing ',comm_dn],'HandleVisibility','on');
plot(lw_loop*1e-6,mean(squeeze(ber_lvsm(1:end,d,:)),1),"LineWidth",1.2,"Marker",m(1+1),"MarkerSize",5,'LineStyle',':','Color',col(cnt,:),'DisplayName',['Lvl Smoothing ',comm_dn],'HandleVisibility','on');
plot(lw_loop*1e-6,mean(squeeze(ber_lvlp(1:end,d,:)),1),"LineWidth",1,"Marker",m(1+3),"MarkerSize",5,'LineStyle','-.','Color',col(cnt,:),'DisplayName',['Lvl Lowpass ',comm_dn],'HandleVisibility','on');
set(gca,'yscale','log');
set(gca,'xscale','log');
%xticklabels([10 100 1000 10000]);
grid minor
yline(3.8e-3,'LineWidth',2,'LineStyle','--','HandleVisibility','off');
ylim([1e-3 4e-2]);
ylabel("BER");
xlabel("Linewidth in MHz")
legend
cnt = cnt+1;
end
figure(1)
contour(lw_loop,sir_loop,thres_a0,16:0.4:21,'LineWidth',2,'FaceAlpha',0.3,'ShowText','on',"LabelFormat","%0.1f dB");
clim([16 21]);
ylabel("Bandwidth in Multiples of Linewidth");
xlabel("Linewidth in MHz");
% set(gca,'yscale','log');
grid minor
title("MPI removal - Optimization of Lowpass Filter Bandwidth")
figure(2)
contour(lw_loop,sir_loop([1:10,12:end]),thres_a0([1:10,12:end],:),16:0.3:21,'LineWidth',2,'FaceAlpha',0.3,'ShowText','on',"LabelFormat","%0.1f dB");
clim([16 21]);
ylabel("Window Length");
xlabel("Linewidth in MHz");
set(gca,'yscale','log');
grid minor
title("MPI removal - Optimization of Averaging Window Length")
%% Plot Winlen Contour
hdfec = 3.8e-3.*ones(size(sir_loop));
for dc = 1:size(data,2)
for lw = 1:size(data,3)
for s = 1:size(data,1)
ber_lvlp(s,dc,lw) = data{s,dc,lw}.ber_dcsm;
% ber_dcsm(wl,lw,s) = data{wl,s,lw}.ber_dcsm;
end
a_bm = InterX([sir_loop;squeeze(ber_lvlp(:,dc,lw))'],[sir_loop;hdfec]);
% a_dcsm = InterX([sirloop;squeeze(ber_dcsm(wl,lw,:))'],[sirloop;hdfec]);
try
thres_a0(dc,lw) = -a_bm(1);
%thres_a1(wl,lw) = -a_dcsm(1);
catch
thres_a0(dc,lw) = NaN;
%thres_a1(wl,lw) = NaN;
end
end
end
figure(1)
contour(lw_loop,bw_loop,thres_a0,14:0.2:21,'LineWidth',1.5,'FaceAlpha',0.3,'ShowText','on',"LabelFormat","%0.1f dB");
a = flip(cbrewer2('seq','Spectral',32));
a = [a(1:12,:); a(22:end,:)];
colormap(a);
clim([16 21]);
ylabel("Window Length");
xlabel("Linewidth in MHz");
yticks(bw_loop);
yticklabels(bw_loop);
set(gca,'yscale','log');
set(gca,'xscale','log');
grid minor
%% Plot DC Tap Contour
hdfec = 3.8e-3.*ones(size(bw_loop));
thres_a0 = zeros(size(ber,1),size(ber,3));
thres_a1 = zeros(size(ber,1),size(ber,3));
for dc = 1:size(ber,1)
for lw = 1:size(ber,3)
a_lvsm = InterX([bw_loop;ber(dc,:,lw)],[bw_loop;hdfec]);
thres_a0(dc,lw) = -a_lvsm(1);
a1 = InterX([bw_loop;ber_a1(dc,:,lw)],[bw_loop;hdfec]);
thres_a1(dc,lw) = -a1(1);
end
end
figure(1)
subplot(2,1,1)
contour(lw_loop,sir_loop,thres_a0,16:0.5:21,'LineWidth',3,'FaceAlpha',0.3,'ShowText','on',"LabelFormat","%0.1f dB");
clim([16 21]);
ylabel("DC Tap");
xlabel("Linewidth in MHz");
set(gca,'yscale','log');
grid minor
subplot(2,1,2)
contour(lw_loop,sir_loop,thres_a1,16:0.5:21,'LineWidth',3,'FaceAlpha',0.3,'ShowText','on',"LabelFormat","%0.1f dB");
clim([16 21]);
ylabel("DC Tap");
xlabel("Linewidth in MHz");
set(gca,'yscale','log');
grid minor
%% Plot Curves of required SIR to see the minimum a bit better
col = flip(cbrewer2('seq','Spectral',16));
col = col([1:4, 10:end],:);
figure(2)
hold on
for lw = [size(ber,3):-2:2 2 1]
plot(sir_loop,thres_a0(:,lw),'DisplayName',[' Linewidth: ',num2str(lw_loop(lw)*1e-6), ' MHz'],'Color',col(lw,:),'Marker','o','MarkerFaceColor',col(lw,:),'LineWidth',2);
set(gca,'xscale','log');
end
xlabel("DC Tap Value");
ylabel("Required SIR to rech FEC in dB");
%%
col = linspecer(7);
figure(3)
cnt=1;
for lw = [1,2,11]
for i = 1:length(sir_loop)-1
subplot(1,3,cnt)
hold on
plot(-1.*bw_loop,ber(i,:,lw),"LineWidth",2,"Marker","o","MarkerSize",5,'Color',col(i,:),'DisplayName',['DC tap ',num2str(sir_loop(i))]);
plot(-1.*bw_loop,ber_a1(i,:,lw),"LineWidth",2,"Marker","x","MarkerSize",5,'LineStyle','--','Color',col(i,:),'DisplayName',['A1. DC tap ',num2str(sir_loop(i))]);
yline(3.8e-3,'LineWidth',2,'LineStyle','--','HandleVisibility','off');
set(gca,'yscale','log');
grid minor
xlim([15,30]);
ylim([1e-4,1e-2]);
xlabel("SIR in dB");
ylabel("BER");
title(['BER for different SIR;',' Linewidth: ',num2str(lw_loop(lw)*1e-6), ' MHz'])
text(25,4.2e-3,"FEC $3.8 e^{-3}$");
end
cnt = cnt+1;
end
legend

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projects/IMDD_base_system/setup_simulation.m Normal file
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lw = [0.1e6 1e6 10e6];
for lp = 1
rng(9);
%% A) Set Simulation Variables
sir = -18;
delay = 50; %mpi delay in meter
fiblen = 0; %main link in km
laser_linewidth =5e6;
O = 19; %order of prbs
N = 2^(O-1); %length of prbs
[~,seed] = prbs(O,1); %initialize first seed of prbs
% Modulation
M = 4; %PAM-M
bitpattern = zeros(N,log2(M));
% Symbol Rate
fsym = 112e9;
% DAC Rate
fdac = 120e9;
% Simulation oversampling rate "k";
kover = 16;
% ADC Rate
fadc = 256e9;
% Simulation frequency in "analog domain"
fsimu = kover * fdac ;
%% B) CONSTRUCT ALL CLASSES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
digimod = PAMmapper(M,0);
pulseform = Pulseformer("pulseform","rrc","fdac",fdac,"fsym",fsym,"pulselength",32,"rrcalpha",0.027);
awg = AWG('fdac',fdac,'kover',kover,'lpf_active',1,'f_cutoff',56e9,'lpf_type',filtertypes.gaussian,'bit_resolution',5.5);
lp_laser = Filter('filtdegree',1,"f_cutoff",50e9,"fsamp",fdac*kover,"filterType",filtertypes.bessel_inp);
u_pi = 3.5;
vbias = (0.5*u_pi)-u_pi;
extmodlaser = EML("mode",eml_mode.im_cosinus,"power",5,"fsimu",fsimu,"lambda",1310,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth);
fib = Fiber("fsimu",fdac*kover,"fiber_length",fiblen,"alpha",0.2,"D",16,"lambda0",thz2nm(193.1),"gamma",0);
reflectionpoint = Amplifier("amp_mode","ideal_no_noise","gain_mode","gain","amplification_db",sir);
reflectionprop = Fiber("fsimu",fdac*kover,"fiber_length",delay/1000,"alpha",0.2,"D",16,"lambda0",1550,"gamma",0);
opticatten = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",-8);
phdiode = Photodiode("fsimu",fdac*kover,"dark_current",2e-08,"responsivity",1,"temperature",20);
lp_diode = Filter('filtdegree',1,"f_cutoff",50e9,"fsamp",fdac*kover,"filterType",filtertypes.bessel_inp);
scp = Scope("fsimu",fdac*kover,"fadc",fadc,...
"delay",0,"fixed_delay",0,"lpf_bw",113e9,"filtertype",filtertypes.butterworth,...
"samplingdelay",0,"rand_samplingdelay",0,"freq_offset",0,"samp_jitter",0,...
"adcresolution",6,"quantbuffer",0.1,'block_dc',1);
eq = EQ("K",2,"plottrain",0,"plotfinal",0,...
"training_length",4096,"training_loops",2,...
"Ne",[50,5,3],"Nb",[3,0,0],...
"DCmu",0.05,"DDmu",[0.0004 0.0005 0.0006 0.0007 ],"DFEmu",0.005,"FFEmu",0.00,...
"dd_loops",2,"epsilon",[10 100 1000 ],"M",2,...
"thres",[0.005 0.004 0.0005 ],"l1act",0,"delay",0,"rho",0.0005,"ideal_dfe",0,"DB_aim",0);
eq = EQ_silas("Ne",[50,5,3],"Nb",[2,0,0],"trainlength",4096,...
"sps",2,...
"mu_dc_dd",0.05,...
"mu_dc_train",0.05,...
"mu_ffe_train",0,...
"mu_dfe_train",0.005,...
"mu_ffe_dd",[0.0004 0.0004 0.0004],...
"mu_dfe_dd",0.005,...
"ddloops",3,...
"trainloops",4,...
"dcmode",1);
%% C) PROCESS TX %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 1) PRBS Generation
for i = 1:log2(M)
[bitpattern(:,i),seed] = prbs(O,N,seed);
end
% 2 ) Build Inf. signal class
bits = Informationsignal(bitpattern);
% 3) Digi modulation -> PAM-M signal
digimod_out = digimod.map(bits);
% 4) Pulse shaping -> racos
X = pulseform.process(digimod_out);
% 5) AWG (lowpass, quantization, sample and hold)
X = awg.process(X);
% 6) Lowpass behavior of laser and hf-cable? why twice?
X = lp_laser.process(X);
% X = lp_laser.process(X);
% 7) Normalize signal
X = X.normalize("mode","oneone");
X.signal = X.signal .* 1.3800;
%% D) PROCESS OPTICAL CHANNEL %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 1) Laser; Modulation -> OPTICAL DOMAIN
[X,extmodlaser] = extmodlaser.process(X);
% 2) Main fiber propagation
X = fib.process(X);
if delay ~= 0
% 3) Reflection
% Reflection is just an attenuation
R = reflectionpoint.process(X);
% Propagate back and forth (actual fiber propagation)
R = reflectionprop.process(R);
% Delay the reflected signal
[R,n] = R.delay("delay_meter",delay);
% Add together
col = cbrewer2('qual','Paired',8);
xax = (1:X.length);% / fsimu * (physconst("LightSpeed")/1.4677);
xax_sec = (1:X.length) / fsimu .* 1e6;%* (physconst("LightSpeed")/1.4677);
xax_sec = xax_sec(n:end).';
thresh = pi/4;
phaseX = phase(X.signal(n:end));
phaseR = phase(R.signal(n:end));
phasediff = wrapToPi(phaseX-phaseR);
[pos_high] = find(abs(phasediff)>thresh);
[pos_low] = find(abs(phasediff)<=thresh);
figure(6);hold on;histogram(phaseX-phaseR,500,'EdgeAlpha',0)
figure()
subplot(3,1,1)
scatter(xax_sec.',wrapToPi(phaseX),4,'.','MarkerEdgeColor',col(2,:),'DisplayName','Desired Signal')
hold on
scatter(xax_sec,wrapToPi(phaseR),4,'.','MarkerEdgeColor',col(1,:),'DisplayName','Reflected Signal')
hold on
lg = legend;
lg.Location = "southwest";
xlim([xax_sec(1) xax_sec(end)]);
xlabel('time in $\mu$s')
ylim([-pi pi]);
yticks([-pi 0 pi])
yticklabels({'$-\pi$',0, '$\pi$'})
ylabel('$\phi$')
subplot(3,1,2)
scatter(xax_sec(pos_low),phasediff(pos_low),4,'.','MarkerEdgeColor',col(5,:),'DisplayName','Phase Difference')
hold on
scatter(xax_sec(pos_high),phasediff(pos_high),4,'.','MarkerEdgeColor',col(2,:),'HandleVisibility','off')
% yline(thresh,'LineWidth',2,'LineStyle','-','HandleVisibility','off')
% yline(-thresh,'LineWidth',2,'LineStyle','-','HandleVisibility','off')
lg = legend;
lg.Location = "southwest";
xlabel('time in $\mu$s')
xlim([xax_sec(1) xax_sec(end)]);
ylim([-pi pi]);
yticks([-pi 0 pi])
yticklabels({'$-\pi$',0, '$\pi$'})
ylabel('$\Delta \phi$')
X.signal = X.signal(n:end);
R.signal = R.signal(n:end);
X1 = X;
X = X+R;
subplot(3,1,3)
scatter(xax_sec(pos_low),abs(X.signal(pos_low).^2)*1000,4,'.','MarkerEdgeColor',col(5,:),'DisplayName','Constructive Interference');
hold on
scatter(xax_sec(pos_high),abs(X.signal(pos_high).^2)*1000,4,'.','MarkerEdgeColor',col(2,:),'DisplayName','Destructive Interference');
%scatter(xax_sec(pos_high),abs(X1.signal(pos_high).^2)*1000,4,'.','MarkerEdgeColor',col(1,:),'MarkerFaceAlpha',0.3,'DisplayName','Destructive Interference');
xlim([xax_sec(1) xax_sec(end)]);
xlabel('time in $\mu$s')
lg = legend;
lg.Location = "southwest";
ylabel('Optical power in mW');
disp(['SIR ',num2str(10*log10(X.power/R.power))]);
% cut reference signal to correct length (nessecary due to MPI delay)
digimod_out.signal = digimod_out.signal(round(n * fsym/fsimu) : end,:);
bitpattern = bitpattern(round(n * fsym/fsimu):end,:);
end
% plot(angle(R.signal))
% 4) Attenuation
X = opticatten.process(X);
% 5) Photo Diode -> ELECTRICAL DOMAIN
X = phdiode.process(X);
X = lp_diode.process(X);
%% E) PROCESS RX %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 1) Oscilloscope (Sampling to f_adc; Quantization; Bandwidth Limitation)
X = scp.process(X);
% 2) Resample to 2x symbol rate
X = X.resample("fs_out",2*fsym,"fs_in",fadc);
% 3) Normalize
Eq_in = X.normalize("mode","rms");
% 4) Equalize
% MPI reduction DC removal BEFORE EQ
wl = 3000; % symbols
Eq_in.signal = Eq_in.signal - 1/wl .* movsum( Eq_in.signal,[wl/2,wl/2]);
% Equalize Signal
[Eq_out] = eq.process(Eq_in,digimod_out);
%% A1: MPI reduction DC removal
wl = 1000; % symbols
yk_dcsm = Eq_out;
yk_dcsm.signal = Eq_out.signal - 1/wl .* movsum( Eq_out.signal,[wl/2,wl/2]);
%% A2: MPI reduction Level wise error removal
yk_lvsm = Eq_out;
yk_lvlp = Eq_out;
pre_decision_level_uni = digimod.decide_pamlevel(Eq_out);
pre_decision_level_bi = ( pre_decision_level_uni*2-3 ) .* 1/sqrt(5);
e = Eq_out.signal - pre_decision_level_bi;
lp_mpi = Filter('filtdegree',1,"f_cutoff",2e6,"fsamp",fsym,"filterType",filtertypes.bessel_inp);
filtered = lp_mpi.process(e);
wl = 30; % symbols
smoothed = ( 1/wl .* movsum(e,[wl/2,wl/2]) );
% remove interference
for level = 0:3
yk_lvsm.signal(pre_decision_level_uni==level) = yk_lvsm.signal(pre_decision_level_uni==level) - smoothed(pre_decision_level_uni==level);
yk_lvlp.signal(pre_decision_level_uni==level) = yk_lvlp.signal(pre_decision_level_uni==level) - filtered(pre_decision_level_uni==level);
end
% Calc EVM
evm_bm = calc_evm(Eq_out.signal, pre_decision_level_bi);
evm_dcsm = calc_evm(yk_dcsm.signal, pre_decision_level_bi);
evm_lsm = calc_evm(yk_lvsm.signal, pre_decision_level_bi);
evm_llp = calc_evm(yk_lvlp.signal, pre_decision_level_bi);
% figure(1);bar([evm_bm' evm_dcsm' evm_llp' evm_lsm']);ylim([0.01 0.1]);set(gca,'yscale','log');
%% PROCESS RX %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 1) Digi Demod
d_bm = digimod.demap(Eq_out);
d_dcsm = digimod.demap(yk_dcsm);
d_lvsm = digimod.demap(yk_lvsm);
d_lvlp = digimod.demap(yk_lvlp);
% 2) BER
dbit = length(d_bm.signal)-length(bitpattern);
[~,errors_bm,ber_bm,loc] = calc_ber(d_bm.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",1);
[~,errors_dcsm,ber_dcsm] = calc_ber(d_dcsm.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",0);
[~,errors_lvsm,ber_lvsm] = calc_ber(d_lvsm.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",0);
[~,errors_lvlp,ber_lvlp] = calc_ber(d_lvlp.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",0);
% Display BER
disp(['BER benchmark: ', sprintf('%2E',ber_bm), ' ERRORS: ' ,num2str(sum(errors_bm))]);
disp(['BER dc smooth (A1): ', sprintf('%2E',ber_dcsm), ' ERRORS: ' ,num2str(sum(errors_dcsm))]);
disp(['BER lv smooth (A2): ', sprintf('%2E',ber_lvsm), ' ERRORS: ' ,num2str(sum(errors_lvsm))]);
disp(['BER lv lowpas: ', sprintf('%2E',ber_lvlp), ' ERRORS: ' ,num2str(sum(errors_lvlp))]);
%% Generate some Plots
if 1
% SCATTER
col = cbrewer2('Paired',8);
xax = 1:Eq_out.length;
figure(3)
sgtitle('')
subplot(1,3,1)
hold on
eq_decision = digimod.decide_pamlevel(Eq_out);
true_symbols = digimod.decide_pamlevel(digimod_out);
xindices = 1:Eq_in.length;
errorpos = find(loc~=0)*2;
errorpos(errorpos>length(Eq_in.signal)) = length(Eq_in.signal);
correct = find(loc==0)*2;
correct(correct>length(Eq_in.signal)) = length(Eq_in.signal);
scatter(xindices(correct),Eq_in.signal(correct),4,'.','MarkerEdgeColor',col(4,:),'DisplayName','After EQ');
hold on
scatter(xindices(errorpos),Eq_in.signal(errorpos),6,'x','MarkerEdgeColor',col(6,:),'DisplayName','Wrong Decision');
hold off
xlim([1, xindices(end)]);
ylim([-3 3]);
xlabel('Sampling Index')
ylabel('Amplitude')
a = legend;
a.Location = "best";
subplot(1,3,2)
xindices = 1:Eq_out.length;
xax_sec = (1:Eq_out.length) / fsym .* 1e6;
scatter(xax_sec(loc==0),Eq_out.signal(loc==0),4,'.','MarkerEdgeColor',col(4,:),'DisplayName','After EQ');
hold on
scatter(xindices(loc~=0),Eq_out.signal(loc~=0),8,'x','MarkerEdgeColor',col(6,:),'DisplayName','Wrong Decision');
hold off
xlim([1, xax(end)]);
ylim([-2 2]);
xlabel('Sampling Index')
ylabel('Amplitude')
legend
a = legend;
a.Location = "best";
hold off
subplot(1,3,3)
xindices = 1:yk_lvsm.length;
scatter(xindices(loc==0),yk_lvsm.signal(loc==0),4,'.','MarkerEdgeColor',col(4,:),'DisplayName','After A2');
hold on
scatter(xindices(loc~=0),yk_lvsm.signal(loc~=0),8,'x','MarkerEdgeColor',col(6,:),'DisplayName','Wrong Decision');
hold off
xlim([1, xax(end)]);
ylim([-2 2]);
xlabel('Sampling Index')
ylabel('Amplitude')
legend
a = legend;
a.Location = "best";
hold off
end
if 0
col = cbrewer2('Paired',8);
figure(11)
clf
subplot(2,1,1)
hold on
plot(digimod_out.signal(4150:4175),'DisplayName','Tx','Color',col(1,:),'LineWidth',3);
plot(Eq_out.signal(4150:4175),'DisplayName','Rx after EQ','Color',col(6,:),'LineWidth',1);
title('Modulated Sequence Zoom');
legend
hold off
subplot(2,1,2)
hold on
stem(d_bm.signal(4150:4175,1),'DisplayName','Tx','Color',col(1,:),'LineStyle','-','LineWidth',5)
stem(bitpattern(4150:4175,1)','DisplayName','Rx','Color',col(6,:),'LineStyle','--','LineWidth',2)
title('Bitpattern Tx - Rx');
legend
hold off
end
end