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Equalizer with different DC removal positions

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This commit is contained in:
Silas Oettinghaus
2023-09-29 08:18:22 +02:00
parent 8b3bc688dd
commit fce274c4cf
6 changed files with 443 additions and 326 deletions
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2
Classes/01_transmit/AWG.m
View File

@@ -135,7 +135,7 @@ classdef AWG
elec_out = repmat(elec_out,obj.repetitions,obj.kover);
elec_out = reshape(elec_out',[],1);
% 3. Add skew (not working so far)
% 3. Add skew (not implemented so far)
if obj.skew_active
elec_out = obj.skew(elec_out);
end

1
Classes/02_optical/EML.m
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@@ -111,7 +111,6 @@ classdef EML
%scale with noisefactor
noi = noi * obj.noisefactor;
%cumsum to accumulate noise over time vector
noi = cumsum(noi);

63
Classes/04_DSP/EQ_silas.m
View File

@@ -49,6 +49,8 @@ classdef EQ_silas < handle
trainloops
ddloops
dcmode
@@ -73,6 +75,8 @@ classdef EQ_silas < handle
options.mu_dc_dd = 0.01;
options.mu_combined_dd = [0.0004 0.0005 0.0006 0.0007 ];
options.dcmode
end
fn = fieldnames(options);
@@ -151,18 +155,32 @@ classdef EQ_silas < handle
m = m+1;
%get Sigal input vectors with correct length for VNLE
x_in_block = obj.x_in(obj.Ne(1)+n+(obj.sps-1):-1:n+obj.sps).';
if obj.dcmode ~= 3
x_in_block = obj.x_in(obj.Ne(1)+n+(obj.sps-1):-1:n+obj.sps).';
elseif obj.dcmode == 3
x_in_block = obj.x_in(obj.Ne(1)+n+(obj.sps-1):-1:n+obj.sps).' + obj.e_dc;
end
x_in_vnle_format = obj.calcVNLENonlinVecs(x_in_block,obj.Ie2,obj.Ie3,obj.Ne,[1,1,1]);
%get Reference input vectors with correct length for VNLE
d_block = obj.d(obj.Nb(1)-obj.delay+m-2:-1:m-obj.delay-1).';
d_vnle_format = obj.calcVNLENonlinVecs(d_block,obj.Ib2,obj.Ib3,obj.Nb,obj.d_norm);
% Calculate the Error
obj.e_ffe = obj.e.' * x_in_vnle_format;
obj.e_dfe = obj.b.' * d_vnle_format;
obj.error = obj.e_dc + obj.e_ffe - obj.e_dfe - obj.d(obj.Nb(1)-1+m-obj.delay);
obj.e_ffe = obj.e.' * x_in_vnle_format;
% Calculate the Error
if obj.dcmode == 1
obj.error = obj.e_dc + obj.e_ffe - obj.e_dfe - obj.d(obj.Nb(1)-1+m-obj.delay);
elseif obj.dcmode == 2
obj.e_ffe = obj.e_ffe + obj.e_dc;
obj.error = obj.e_ffe - obj.e_dfe - obj.d(obj.Nb(1)-1+m-obj.delay);
elseif obj.dcmode == 3
obj.error = obj.e_ffe - obj.e_dfe - obj.d(obj.Nb(1)-1+m-obj.delay);
end
%update FFE coefficients with LMS
obj.e = obj.e - obj.error*conj(x_in_vnle_format)*obj.mu_ffe_train;
@@ -179,6 +197,7 @@ classdef EQ_silas < handle
end
function decisionDirectedMode(obj)
%start the dd mode with coefficients from training
@@ -195,6 +214,10 @@ classdef EQ_silas < handle
ones(1,obj.Ce(2))*obj.mu_combined_dd(2)... %2nd order ffe
ones(1,obj.Ce(3))*obj.mu_combined_dd(3)... %3rd order ffe
ones(1,sum(obj.Cb))*obj.mu_combined_dd(4)]); %all order dfe
mu_ffe = [ones(1,obj.Ce(1))*obj.mu_combined_dd(1)... %1st order ffe
ones(1,obj.Ce(2))*obj.mu_combined_dd(2)... %2nd order ffe
ones(1,obj.Ce(3))*obj.mu_combined_dd(3)];
mu_dfe = [ones(1,sum(obj.Cb))*obj.mu_combined_dd(4)];
end
y = zeros(1,floor(obj.x_length/obj.sps));
@@ -207,29 +230,47 @@ classdef EQ_silas < handle
m=m+1;
%get Sigal input vectors with correct length for VNLE
x = obj.x_in(obj.Ne(1)+k-1:-1:k).';
if obj.dcmode ~= 3
x = obj.x_in(obj.Ne(1)+k-1:-1:k).';
elseif obj.dcmode == 3
x = obj.x_in(obj.Ne(1)+k-1:-1:k).' + obj.e_dc;
end
x_vnle = obj.calcVNLENonlinVecs(x,obj.Ie2,obj.Ie3,obj.Ne,[1,1,1]);
%combine FFE with DFE to one vector (cursor between the two sequences)
x_d = [x_vnle;-d_vnle];
%Apply filter
y(m) = obj.e_dc + x_d.'* coeff;
if obj.dcmode == 1
y(m) = obj.e_dc + x_d.'* coeff;
elseif obj.dcmode == 2 || obj.dcmode == 3
% x_ffe = obj.e.' * x_vnle;
% x_dfe = obj.b.' * d_vnle;
% y(m) = x_ffe - x_dfe;
y(m) = x_d.'* coeff;
end
%Decision
[~,symbol_idx] = min(abs(y(m) - obj.d_constellation)); % decision for closest constellation point
d_hat(k) = obj.d_constellation(symbol_idx);
%Error between FFE & DFE filtered signal and Decision
obj.error = y(m) - d_hat(k);
if obj.dcmode == 1 || obj.dcmode == 3
obj.error = y(m) - d_hat(k);
elseif obj.dcmode == 2
obj.error = y(m) - d_hat(k) + obj.e_dc;
end
%Update coefficients (both FFE and DFE)
obj.e = obj.e - obj.error * mu_ffe * conj(x_vnle);
obj.b = obj.b + obj.error * mu_dfe * conj(d_vnle);
coeff = coeff - mu_mat*obj.error*conj(x_d);
if 1 %mu_mat ~= 0
obj.e_dc = obj.e_dc - obj.mu_dc_dd * obj.error;
obj.error_log(ddloop,m) = obj.e_dc.^2;
end
obj.e_dc = obj.e_dc - obj.mu_dc_dd * obj.error;
obj.error_log(ddloop,m) = obj.e_dc.^2;
% Append new decision to decision feedback
if obj.Nb(1) > 0

312
imddmodel.m
View File

@@ -1,206 +1,218 @@
function output = imddmodel(sir,winlen,linewidth)
function output = imddmodel(sir,dcmode)
for realiz = 1:3
rng(realiz);
%% Set Simulation Variables
sir = sir;
delay = 50; %mpi delay in meter
delay = 0;10+(10*realiz); %mpi delay in meter
fiblen = 0; %main link in km
laser_linewidth = linewidth;
O = 17; %order of prbs
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 ;
%% CONSTRUCT ALL CLASSES
%% B) CONSTRUCT ALL CLASSES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
digimod = PAMmapper(M,0);
pulseform = Pulseformer("pulseform","rrc","fdac",fdac,"fsym",fsym,"pulselength",32,"rrcalpha",0.1);
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",15,"fsimu",fsimu,"lambda",1550,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth);
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",2*delay/1000,"alpha",0.2,"D",16,"lambda0",1550,"gamma",0);
opticatten = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",0);
edfaamp = Amplifier("amp_mode","edfa_increase_nase","gain_mode","output_power","amplification_db",0,"nase_mode","generate_ase","noifig",10.5);
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",1024,"training_loops",5,...
"Ne",[50,0,0],"Nb",[0,0,0],...
"DCmu",0,"DDmu",[0.0004 0.0004 0.0004 0.0004 ],"DFEmu",0.005,"FFEmu",0.00,...
"dd_loops",2,"epsilon",[10 100 1000 ],"M",4,...
"thres",[0.005 0.004 0.0005 ],"l1act",0,"delay",1,"rho",0.0005,"ideal_dfe",0,"DB_aim",0);
%% PROCESS
% PRBS Generation
"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
bitpattern = [bitpattern ; flip(bitpattern)];
%bitpattern = prms_out';
% Build Inf. signal class
bits = Informationsignal(bitpattern);
% Digi Mod
mod_out = digimod.map(bits);
% merken für EQ training
reference = mod_out;
% shape shape
X = pulseform.process(mod_out);
% AWG -> ELECTRICAL DOMAIN
awg_out = awg.process(X);
X = lp_laser.process(awg_out);
X = lp_laser.process(X);
X = X.normalize("mode","oneone");
X.signal = X.signal .* 1.3800;
% Laser; Modulation -> OPTICAL DOMAIN
X = extmodlaser.process(X);
% Fiber Propagation
X = fib.process(X);
%% Reflect with attenuation
% 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
% Propagate back and forth (actual fiber propagation)
R = reflectionprop.process(R);
% disp(['SIR ',num2str(10*log10(X.power/R.power))]);
% Delay
R = R.delay("delay_meter",delay);
% 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
%%
X = opticatten.process(X);
% X = edfaamp.process(X);
% Photo Diode -> ELECTRICAL DOMAIN
X = phdiode.process(X);
X = lp_diode.process(X);
% Oscilloscope (Sampling to f_adc; Quantization; Bandwidth Limitation)
X = scp.process(X);
% Resample to Symbol Rate
X = X.resample("fs_out",2*fsym,"fs_in",fadc);
% Normalize
Eq_in = X.normalize("mode","rms");
% Equalizer
Eq_out = eq.process(Eq_in,reference);
%% MPI reduction DC removal
wl = winlen; % symbols
% 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]);
%% MPI reduction Level wise error removal
%% 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",max(10*linewidth,1e6),"fsamp",fsym,"filterType",filtertypes.bessel_inp);
lp_mpi = Filter('filtdegree',1,"f_cutoff",2e6,"fsamp",fsym,"filterType",filtertypes.bessel_inp);
filtered = lp_mpi.process(e);
wl = winlen; % symbols
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
%% EVM
[evm_bm(realiz,:),std_bm(realiz,:)] = calc_evm(Eq_out.signal, pre_decision_level_bi);
[evm_dcsm(realiz,:),std_dcsm(realiz,:)] = calc_evm(yk_dcsm.signal, pre_decision_level_bi);
[evm_lsm(realiz,:),std_lsm(realiz,:)] = calc_evm(yk_lvsm.signal, pre_decision_level_bi);
[evm_llp(realiz,:),std_llp(realiz,:)] = calc_evm(yk_lvlp.signal, pre_decision_level_bi);
%% 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);
%% BER
dbit = length(d_bm.signal)-length(bitpattern);
[~,errors_bm,ber_bm(realiz)] = calc_ber(d_bm.signal(1:end-dbit,:) ,bitpattern(1:end,:),10000);
[~,errors_dcsm,ber_dcsm(realiz)] = calc_ber(d_dcsm.signal(1:end-dbit,:) ,bitpattern(1:end,:),10000);
[~,errors_lvsm,ber_lvsm(realiz)] = calc_ber(d_lvsm.signal(1:end-dbit,:) ,bitpattern(1:end,:),10000);
[~,errors_lvlp,ber_lvlp(realiz)] = calc_ber(d_lvlp.signal(1:end-dbit,:) ,bitpattern(1:end,:),10000);
% disp(['BER benchmark: ', sprintf('%2E',ber_bm), ' ERRORS: ' ,num2str(sum(errors_bm))]);
% disp(['BER dc smooth: ', sprintf('%2E',ber_dcsm), ' ERRORS: ' ,num2str(sum(errors_dcsm))]);
% disp(['BER lv smooth: ', sprintf('%2E',ber_lvsm), ' ERRORS: ' ,num2str(sum(errors_lvsm))]);
% disp(['BER lv lowpas: ', sprintf('%2E',ber_lvlp), ' ERRORS: ' ,num2str(sum(errors_lvlp))]);
%% 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
@@ -210,15 +222,5 @@ output.ber_dcsm = mean(ber_dcsm);
output.ber_lvsm = mean(ber_lvsm);
output.ber_lvlp = mean(ber_lvlp);
output.evm_bm = mean(evm_bm);
output.evm_dcsm = mean(evm_dcsm);
output.evm_lsm = mean(evm_lsm);
output.evm_llp = mean(evm_llp);
output.std_bm = mean(std_bm);
output.std_dcsm = mean(std_dcsm);
output.std_lsm = mean(std_lsm);
output.std_llp = mean(std_llp);
end

116
run_loop.m
View File

@@ -1,73 +1,48 @@
clear
clear
sir_loop = [-22:1.5:-15];
sir_loop = [-25:2:-13];
sir_loop = 0;
lw_loop = [1,2,3];
%dc_tap_loop = [0.001 0.005 0.01 0.05 0.1 0.25];
bw_loop = [1:10];
lw_loop = [0e6:0.2e6:1e6 2e6:2e6:10e6 20e6:20e6:100e6];
data = cell(length(sir_loop),length(bw_loop),length(lw_loop));
data = cell(length(sir_loop),length(lw_loop));
iterations=size(data);
for ix = 1:numel(data)
parfor ix = 1:numel(data)
[u1,u2,u3] = ind2sub(iterations,ix);
[u1,u2] = ind2sub(iterations,ix);
output = imddmodel(sir_loop(u1),bw_loop(u2),lw_loop(u3));
output = imddmodel(sir_loop(u1),lw_loop(u2));
data{ix} = output;
% ber(ix) = BER.ber;
% ber_a1(ix) = BER.ber_a1;
disp(ix)
end
%% 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
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
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);
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');
set(gca,'xscale','log');
grid minor
yline(3.8e-3,'LineWidth',2,'LineStyle','--','HandleVisibility','off');
set(gca,'xdir','reverse');
%% Plot
%% Plot
col = linspecer(8);
figure(1)
hold on
@@ -122,6 +97,43 @@ 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
@@ -167,7 +179,7 @@ end
xlabel("DC Tap Value");
ylabel("Required SIR to rech FEC in dB");
%%
%%
col = linspecer(7);
figure(3)
cnt=1;
@@ -182,7 +194,7 @@ for lw = [1,2,11]
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");

275
setup_simulation.m
View File

@@ -1,26 +1,21 @@
sir_loop = -22;
lw = [0.1e6 1e6 10e6];
for lp = 1
dc_mu = 0.05;
rng(9);
sir = sir_loop(1);
%% A) Set Simulation Variables
rng(lp);
%% Set Simulation Variables
sir = sir;
delay = 20; %mpi delay in meter
sir = -18;
delay = 10; %mpi delay in meter
fiblen = 0; %main link in km
laser_linewidth =1e6;
laser_linewidth =5e6;
O = 17; %order of prbs
O = 18; %order of prbs
N = 2^(O-1); %length of prbs
[~,seed] = prbs(O,1); %initialize first seed of prbs
@@ -44,7 +39,8 @@ for lp = 1
fsimu = kover * fdac ;
%% CONSTRUCT ALL CLASSES
%% B) CONSTRUCT ALL CLASSES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
digimod = PAMmapper(M,0);
@@ -56,12 +52,12 @@ for lp = 1
u_pi = 3.5;
vbias = (0.5*u_pi)-u_pi;
extmodlaser = EML("mode",eml_mode.im_cosinus,"power",15,"fsimu",fsimu,"lambda",1550,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth);
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",2*delay/1000,"alpha",0.2,"D",16,"lambda0",1550,"gamma",0);
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);
@@ -77,101 +73,157 @@ for lp = 1
eq = EQ("K",2,"plottrain",0,"plotfinal",0,...
"training_length",4096,"training_loops",2,...
"Ne",[50,5,3],"Nb",[3,2,2],...
"DCmu",dc_mu,"DDmu",[0.0004 0.0005 0.0006 0.0007 ],"DFEmu",0.005,"FFEmu",0.005,...
"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",[50,5,0],"Nb",[3,2,0],"trainlength",4096,"mu_dc_dd",0.001,"mu_dc_train",0.05,"mu_ffe_train",0.005,"mu_combined_dd",[0.0004 0.0006 0.0003 0.005],"ddloops",5);
eq2 = EQ_silas("Ne",[30,0,0],"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',3);
%% PROCESS
%% C) PROCESS TX %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% PRBS Generation
% 1) PRBS Generation
for i = 1:log2(M)
[bitpattern(:,i),seed] = prbs(O,N,seed);
end
% Build Inf. signal class
bits = Informationsignal(bitpattern);
% 2 ) Build Inf. signal class
bits = Informationsignal(bitpattern);
% Digi Mod
mod_out = digimod.map(bits);
% 3) Digi modulation -> PAM-M signal
digimod_out = digimod.map(bits);
% merken für EQ training
reference = mod_out;
% 4) Pulse shaping -> racos
X = pulseform.process(digimod_out);
% shape shape
X = pulseform.process(mod_out);
% 5) AWG (lowpass, quantization, sample and hold)
X = awg.process(X);
% AWG -> ELECTRICAL DOMAIN
X = awg.process(X);
% 6) Lowpass behavior of laser and hf-cable? why twice?
X = lp_laser.process(X);
X = lp_laser.process(X);
X = lp_laser.process(X);
X = lp_laser.process(X);
X = X.normalize("mode","oneone");
X.signal = X.signal .* 1.3800;
% Laser; Modulation -> OPTICAL DOMAIN
[X,extmodlaser] = extmodlaser.process(X);
% Fiber Propagation
X = fib.process(X);
%% Reflect with attenuation
R = reflectionpoint.process(X);
% Propagate back and forth
R = reflectionprop.process(R);
% 7) Normalize signal
X = X.normalize("mode","oneone");
X.signal = X.signal .* 1.3800;
% Delay
[R,n] = R.delay("delay_meter",delay);
%% D) PROCESS OPTICAL CHANNEL %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Add together
X.signal = X.signal(n:end);
R.signal = R.signal(n:end);
% 1) Laser; Modulation -> OPTICAL DOMAIN
[X,extmodlaser] = extmodlaser.process(X);
disp(['SIR ',num2str(10*log10(X.power/R.power))]);
% 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_mtr = (1:X.length) / fsimu * (physconst("LightSpeed")/1.4677);
% thresh = 0.7;
% phaseX = phase(X.signal);
% phaseR = phase(R.signal);
% phasediff = wrapToPi(phaseX-phaseR);
% [pos_high] = find(abs(phasediff)>thresh);
% [pos_low] = find(abs(phasediff)<=thresh);
%
% figure()
% subplot(3,1,1)
% scatter(xax_mtr,wrapToPi(phaseX),4,'.','MarkerEdgeColor',col(4,:),'DisplayName','Phase of original Signal')
% hold on
% scatter(xax_mtr,wrapToPi(phaseR),4,'.','MarkerEdgeColor',col(7,:),'DisplayName','Phase of delayed Signal')
% hold on
% xline(delay,'LineWidth',4,'LineStyle','--','HandleVisibility','off')
% lg = legend;
% lg.Location = "southwest";
%
% subplot(3,1,2)
% scatter(xax_mtr(pos_low),phasediff(pos_low),4,'.','MarkerEdgeColor',col(6,:),'DisplayName','Phase Difference')
% hold on
% scatter(xax_mtr(pos_high),phasediff(pos_high),4,'.','MarkerEdgeColor',col(4,:),'HandleVisibility','off')
% xline(delay,'LineWidth',4,'LineStyle','--','HandleVisibility','off')
% yline(thresh,'LineWidth',2,'LineStyle','-','HandleVisibility','off')
% yline(-thresh,'LineWidth',2,'LineStyle','-','HandleVisibility','off')
% lg = legend;
% lg.Location = "southwest";
X = X+R;
% subplot(3,1,3)
% scatter(xax_mtr(pos_low),abs(X.signal(pos_low).^2),4,'.','MarkerEdgeColor',col(6,:),'DisplayName','Constructive Interference');
% hold on
% scatter(xax_mtr(pos_high),abs(X.signal(pos_high).^2),4,'.','MarkerEdgeColor',col(4,:),'DisplayName','Destructive Interference');
% xline(delay,'LineWidth',4,'LineStyle','--','HandleVisibility','off')
%
% lg = legend;
% lg.Location = "southwest";
X.signal = X.signal(n:end);
R.signal = R.signal(n:end);
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
X = X+R;
% plot(angle(R.signal))
% 4) Attenuation
X = opticatten.process(X);
%%
X = opticatten.process(X);
% X = edfaamp.process(X);
% 5) Photo Diode -> ELECTRICAL DOMAIN
X = phdiode.process(X);
X = lp_diode.process(X);
% Photo Diode -> ELECTRICAL DOMAIN
X = phdiode.process(X);
X = lp_diode.process(X);
% Oscilloscope (Sampling to f_adc; Quantization; Bandwidth Limitation)
X = scp.process(X);
%% E) PROCESS RX %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Resample to Symbol Rate
X = X.resample("fs_out",2*fsym,"fs_in",fadc);
% 1) Oscilloscope (Sampling to f_adc; Quantization; Bandwidth Limitation)
X = scp.process(X);
% Normalize
Eq_in = X.normalize("mode","rms");
% 2) Resample to 2x symbol rate
X = X.resample("fs_out",2*fsym,"fs_in",fadc);
% Equalizer
reference.signal = reference.signal(round(n * fsym/fsimu) : end,:);
% 3) Normalize
Eq_in = X.normalize("mode","rms");
tracking_speed_bandwidth = eq.FFEmu .* fsym .* 1e-9;
% 4) Equalize
%% MPI reduction DC removal BEFORE EQ
% wl = 1000; % symbols
% Eq_in.signal = Eq_in.signal - 1/wl .* movsum( Eq_in.signal,[wl/2,wl/2]);
% 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]);
[Eq_out] = eq2.process(Eq_in,reference);
% Equalize Signal
[Eq_out] = eq2.process(Eq_in,digimod_out);
%% MPI reduction DC removal
%% 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]);
%% MPI reduction Level wise error removal
%% A2: MPI reduction Level wise error removal
yk_lvsm = Eq_out;
yk_lvlp = Eq_out;
pre_decision_level_uni = digimod.decide_pamlevel(Eq_out);
@@ -183,7 +235,7 @@ for lp = 1
filtered = lp_mpi.process(e);
wl = 100; % symbols
wl = 30; % symbols
smoothed = ( 1/wl .* movsum(e,[wl/2,wl/2]) );
% remove interference
@@ -191,14 +243,8 @@ for lp = 1
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
%
% figure(26);plot(1:length(error_log),error_log(:,end),"LineWidth",0.4);ylim([-0.8 0.8]);ylabel('$\epsilon$'),title(['Linewidth: ',num2str(laser_linewidth*1e-6), 'MHz'])
%
% figure(28);plot(1:length(e),e,"LineWidth",0.4);ylim([-0.8 0.8]);
%% Calc EVM
% Calc EVM
evm_bm = calc_evm(Eq_out.signal, pre_decision_level_bi);
evm_dcsm = calc_evm(yk_dcsm.signal, pre_decision_level_bi);
@@ -207,35 +253,35 @@ for lp = 1
% figure(1);bar([evm_bm' evm_dcsm' evm_llp' evm_lsm']);ylim([0.01 0.1]);set(gca,'yscale','log');
% 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);
% BER
bitpattern = bitpattern(round(n * fsym/fsimu):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,loc] = calc_ber(d_bm.signal(1:end-dbit,:) ,bitpattern(1:end,:),"skip",0,"returnErrorLocation",1);
[~,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
% 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))]);
% disp(['BER dc smooth: ', sprintf('%2E',ber_dcsm), ' ERRORS: ' ,num2str(sum(errors_dcsm))]);
% disp(['BER lv smooth: ', 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);
@@ -244,14 +290,16 @@ for lp = 1
figure(3)
sgtitle('')
subplot(1,2,1)
subplot(1,3,1)
hold on
eq_decision = digimod.decide_pamlevel(Eq_out);
true_symbols = digimod.decide_pamlevel(mod_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');
@@ -264,7 +312,7 @@ for lp = 1
a = legend;
a.Location = "best";
subplot(1,2,2)
subplot(1,3,2)
xindices = 1:Eq_out.length;
scatter(xindices(loc==0),Eq_out.signal(loc==0),4,'.','MarkerEdgeColor',col(4,:),'DisplayName','After EQ');
hold on
@@ -279,16 +327,31 @@ for lp = 1
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
% ERROR IN EQ
figure(13)
plot(diff(eq2.error_log(1,:)));
plot((eq2.error_log(1,:)),'DisplayName','First iteration DD mode','Linewidth',0.5);
hold on;
for i = 1:size(eq2.error_log,1)
plot(diff(eq2.error_log(i,:)));
plot((eq2.error_log(i,:)),'Linewidth',0.5);
end
loc(loc==0) = NaN;
stem(loc.*mean((eq2.error_log(end,:))))
stem(loc.*mean((eq2.error_log(end,:))),'DisplayName','Error Positions')
hold off
end
@@ -301,7 +364,7 @@ for lp = 1
subplot(2,1,1)
hold on
plot(reference.signal(4150:4175),'DisplayName','Tx','Color',col(1,:),'LineWidth',3);
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