%% 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);

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",60e9,"fsamp",fdac,"filterType",filtertypes.bessel_inp);

u_pi = 4.6;
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",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,"gamma",0);

optatten    = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",5);

edfaamp     = Amplifier("amp_mode","edfa_increase_nase","gain_mode","output_power","amplification_db",0,"nase_mode","generate_ase","noifig",5);

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

lp_diode    = Filter('filtdegree',1,"f_cutoff",80e9,"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",1,"rho",0.0005,"ideal_dfe",0,"DB_aim",0);



%% 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);


reference   = mod_out;

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


% AWG -> ELECTRICAL DOMAIN
X           = awg.process(mod_out);

X           = lp_laser.process(X);

X           = X.normalize;

% Laser; Modulation ->  OPTICAL DOMAIN
X           = extmodlaser.process(X);
X.spectrum(fsimu,"displayname",'laser out','figurename','after laser');

%X           = amp.process(X);

% Fiber Propagation
X           = fib.process(X);
X           = optatten.process(X);
X           = edfaamp.process(X);

% Photo Diode -> ELECTRICAL DOMAIN
X           = phdiode.process(X);
X           = lp_diode.process(X);
X.spectrum(fsimu,"displayname",'diode out','figurename','after diode');
% 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);

% INFORMATION SIGNAL
X           = X.normalize;

% Equalizer
eq_out      = eq.process(X,reference);
rx_series   = eq_out.signal;

% Digi Demod 
demap_out   = digimod.demap(eq_out);

% BER
[bits,errors,BER] = calc_ber(demap_out.signal(:,1:end-1),bitpattern(1:end,:)',0);
disp(['BER: ', sprintf('%2E',BER)]);

% disp(demap_out.logbook);



%% Generate some Plots
if 0
    col = cbrewer2('Paired',8);
    
    figure(22)
    clf
%     subplot(3,1,1)
%     hold on
%     plot(reference.signal(10000:end-20),'DisplayName','Tx','Color',col(1,:),'LineWidth',3);
%     plot(rx_series(10000:end-20),'DisplayName','Rx','Color',col(6,:));
%     title('Modulated Sequence Tx - Rx');
%     legend
%     hold off
    subplot(2,1,1)
    hold on
    plot(reference.signal(4150:4175),'DisplayName','Tx','Color',col(1,:),'LineWidth',3);
    plot(rx_series(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(demap_out.signal(1,4150:4175),'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
    
    
    xax = 1:eq_out.length;
    
    figure(12)
    sgtitle('')
    subplot(1,4,1:2)
    scatter(1:4:X.length,X.signal(1:4:end),4,'.','MarkerEdgeColor',col(5,:),'DisplayName','Before EQ');
    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(6,:),'DisplayName','After EQ');
    xlim([1, xax(end)]);
    %ylim([-2 2]);
    xlabel('Sampling Index')
    ylabel('Amplitude')
    legend
end