clear all

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 = 80e9;
% 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

pam_mapper = PAMmapper(M,0);

awg = AWG('preset','M8199B','fdac',fdac,'kover',kover,'lpf_active',1,'f_cutoff',80e9,'lpf_type',filtertypes.gaussian);

fil_50 = Filter('filtdegree',1,"f_cutoff",50e9,"fsamp",fdac,"filterType",filtertypes.bessel_inp);


u_pi = 3.5;
vbias = (0.5*u_pi)-u_pi;
extmodlaser = EML("mode",emlmodes.im_cosinus,"power",5,"fsimu",fsimu,"lambda",1550,"bias",vbias,"u_pi",u_pi,"linewidth",10000);

amp = Amplifier("amp_mode","ideal_no_noise","amplification_db",0,"gain_mode","output_power");

fib = Fiber("fsimu",fdac*kover,"fiber_length",0,"alpha",0.2,"D",17,"lambda0",1550);

phdiode = Photodiode("fsimu",fdac*kover,"dark_current",2e-08,"responsivity",1,"temperature",20);

fil_diode = Filter('filtdegree',1,"f_cutoff",120e9,"fsamp",fdac,"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);

eq = EQ("K",2,"plottrain",0,"plotfinal",1,...
    "training_length",4096,"training_loops",5,...
    "Ne",[50,0,0],"Nb",[0,0,0],...
    "DCmu",0.005,"DDmu",[0.0004 0.0004 0.0004 0.0004 ],"DFEmu",0.005,"FFEmu",0.000,...
    "dd_loops",2,"epsilon",[10 100 1000 ],"M",4,...
    "thres",[0.005 0.004 0.0005 ],"l1act",0,"delay",2,"rho",0.0005,"ideal_dfe",0,"DB_aim",0);

%% PROCESS
% INFORMATION SIGNAL
for i = 1:log2(M)
    [bitpattern(:,i),seed] = prbs(O,N,seed);
end

bits = Informationsignal(bitpattern);

mod_out = pam_mapper.map(bits);

reference = mod_out;

mod_out.signal  = applyPulseShaping(mod_out.signal,fsym,fdac);

% ELECTRICAL DOMAIN
X  = awg.process(mod_out);
X = fil_50.process(X);
X = X.normalize;

% OPTICAL DOMAIN
X  = extmodlaser.process(X);

X  = amp.process(X);

X  = fib.process(X);

X  = phdiode.process(X);

X  = fil_diode.process(X);

% ELECTRICAL DOMAIN
X  = scp.process(X);

X  = X.resample("fs_out",2*fsym,"fs_in",fadc);

% INFORMATION SIGNAL
X  = X.normalize;
eq_out  = eq.process(X,reference);
rx_series = eq_out.signal;

demap_out  = pam_mapper.demap(eq_out);

[bits,errors,BER] = calc_ber(demap_out.signal(:,10000:end-20),bitpattern(10000:end-19,:)',0);


%%
figure(22)
clf
subplot(3,1,1)
hold on
plot(reference.signal(10000:end-20));
plot(rx_series(10000:end-20));
hold off
subplot(3,1,2)
hold on
plot(reference.signal(4150:4175));
plot(rx_series(4150:4175));
hold off
subplot(3,1,3)
hold on
stem(demap_out.signal(1,4150:4175))
stem(bitpattern(4150:4175,1)')
hold off
legend

xax = 1:eq_out.length;
col = cbrewer2('Set1',4);

figure(12)
sgtitle('Laser Linewidth = 10 MHz; SIR = 24 dB ; $N_{1,2}$ = 100')
subplot(1,4,1:2)
scatter(1:X.length,X.signal,4,'.','MarkerEdgeColor',col(2,:),'DisplayName','A1');
xlim([1, xax(end)]);
%ylim([-2 2]);
xlabel('Sampling Index')
ylabel('Amplitude')
legend

subplot(1,4,3:4)
scatter(xax,eq_out.signal,4,'.','MarkerEdgeColor',col(1,:),'DisplayName','No MPI Mitigation');
xlim([1, xax(end)]);
%ylim([-2 2]);
xlabel('Sampling Index')
ylabel('Amplitude')
legend

a = fftshift(xcorr(X.signal(1,:),circshift(bitpattern(:,1)',0)));

% BER
if (length(X.signal) ~= length(bitpattern'))
    warning("TX and RX bitstreams have different length...")
end



disp(demap_out.logbook);
disp(['BER: ', sprintf('%2E',BER)]);