Files
imdd_silas/setup_simulation.m
2023-07-14 14:42:15 +02:00

321 lines
10 KiB
Matlab

sir_loop = -22;
lw = [0.1e6 1e6 10e6];
for lp = 1
dc_mu = 0.05;
sir = sir_loop(1);
rng(lp);
%% Set Simulation Variables
sir = sir;
delay = 20; %mpi delay in meter
fiblen = 0; %main link in km
laser_linewidth =1e6;
O = 17; %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);
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);
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",-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",dc_mu,"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);
%% 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
X = pulseform.process(mod_out);
% AWG -> ELECTRICAL DOMAIN
X = awg.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);
% Delay
[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;
%%
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
reference.signal = reference.signal(round(n * fsym/fsimu) : end,:);
tracking_speed_bandwidth = eq.FFEmu .* fsym .* 1e-9;
%% 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]);
[Eq_out] = eq2.process(Eq_in,reference);
%% 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
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 = 100; % 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
%
% 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
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');
% 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,:);
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
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))]);
%% Generate some Plots
if 1
% SCATTER
col = cbrewer2('Paired',8);
xax = 1:Eq_out.length;
figure(3)
sgtitle('')
subplot(1,2,1)
hold on
eq_decision = digimod.decide_pamlevel(Eq_out);
true_symbols = digimod.decide_pamlevel(mod_out);
xindices = 1:Eq_in.length;
errorpos = find(loc~=0)*2;
correct = find(loc==0)*2;
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(1,2,2)
xindices = 1:Eq_out.length;
scatter(xindices(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
% ERROR IN EQ
figure(13)
plot(diff(eq2.error_log(1,:)));
hold on;
for i = 1:size(eq2.error_log,1)
plot(diff(eq2.error_log(i,:)));
end
loc(loc==0) = NaN;
stem(loc.*mean((eq2.error_log(end,:))))
hold off
end
if 0
col = cbrewer2('Paired',8);
figure(11)
clf
subplot(2,1,1)
hold on
plot(reference.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