%%% Run parameters
% TX
M               = 4;
fsym            = 180e9;

apply_pulsef    = 1;
fdac            = 256e9;
fadc            = 256e9;
random_key      = 1;

db_precode      = 0;
db_encode       = 0;

rcalpha         = 0.05;
kover           = 16;
vbias_rel       = 0.5;
u_pi            = 2.9;
vbias           = -vbias_rel*u_pi;
laser_wavelength    = 1310;
laser_linewidth     = 0;
tx_bw_nyquist   = 1;

% Channel
link_length     = 1;

% RX
rop = 0;
rx_bw_nyquist = 0.99;

vnle_order1 = 50;
vnle_order2 = 3;
vnle_order3 = 3;

vnle_order=[vnle_order1,vnle_order2,vnle_order3];
dfe_order = [0 0 0];

pf_ncoeffs = 1;

alpha = 0;

len_tr  = 4096*2;

mu_ffe1 = 0.0001;
mu_ffe2 = 0.0008;
mu_ffe3 = 0.001;
mu_dc = 0.005;
% mu_dc = 0;

mu_ffe = [mu_ffe1 mu_ffe3 mu_ffe3];
mu_dfe = 0.0004;


dfe_ = sum(dfe_order)>0;

doub_mode = db_mode.no_db;


Pform       = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rc","pulselength",16,"alpha",rcalpha);

db_precode = 0;
db_encode = 0;
duob_mode = db_mode.db_precoded;
apply_pulsef = 1;
[Digi_sig,Symbols,Tx_bits] = PAMsource(...
    "fsym",fsym,"M",M,"order",18,"useprbs",0,...
    "fs_out",fdac,...
    "applyclipping",0,"clipfactor",1.5,...
    "applypulseform",apply_pulsef,"pulseformer",Pform,...
    "randkey",random_key,...
    "mrds_code",0,"mrds_blocklength",512,"duobinary_mode",duob_mode).process();

Digi_sig.spectrum("displayname",'Digi Spectrum','fignum',10,'normalizeTo0dB',1);


%% proof of concept 
Symbols_db = Duobinary().encode(Symbols);
mim_decoded = Duobinary().decode(Symbols_db,"M",M);
rx_bits_mim_decoded = PAMmapper(M,0,"eth_style",0).demap(mim_decoded);
rx_bits_mim_decoded_.signal =  circshift(rx_bits_mim_decoded.signal,0);
[~,~,ber_mim_decode,~]  = calc_ber(rx_bits_mim_decoded_.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
fprintf('BER mim: %.2e \n',ber_mim_decode);

%%


%%%%% AWG
% El_sig = M8199A("kover",kover).process(Digi_sig);
El_sig = AWG("fdac",fdac,"f_cutoff",fsym,"lpf_active",0,"kover",kover,"bit_resolution",12,"upsampling_method","samplehold","precomp_sinc_rolloff",1).process(Digi_sig);
% El_sig.spectrum("displayname",'Digi Spectrum','fignum',100,'normalizeTo0dB',0);
% El_sig = El_sig.setPower(0,"dBm");

%%%%% Low-pass el. components %%%%%%
f_nyquist       = fsym/2;
tx_bwl = tx_bw_nyquist.*f_nyquist;
% tx_bwl = 80e9;
El_sig = Filter('filtdegree',4,"f_cutoff",tx_bwl,"fs",fdac*kover,"filterType",filtertypes.butterworth,"active",true).process(El_sig);
% El_sig.spectrum("displayname",'Digi Spectrum','fignum',100,'normalizeTo0dB',1);

%%%%% Electrical Driver Amplifier %%%%%%
El_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","gain","amplification_db",3).process(El_sig);
El_sig = El_sig.normalize("mode","oneone");

%%%%% MODULATE E/O CONVERSION %%%%%%
[Opt_sig] = EML("mode",eml_mode.im_cosinus,"power",3,"fsimu",El_sig.fs,"lambda",laser_wavelength,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth,"randomkey",random_key+1).process(El_sig);

Opt_sig    = Fiber("fsimu",Opt_sig.fs,"fiber_length",link_length/1000,"alpha",0.3,"D",0,"lambda0",1310,"gamma",0,"Dslope",0.07).process(Opt_sig);

%%%%%% ROP %%%%%%
Rx_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",rop).process(Opt_sig);

%%%%%% PD Square Law %%%%%%
Rx_sig = Photodiode("fsimu",fdac*kover,"dark_current",2e-08,"responsivity",1,"temperature",20,"nep",1.8e-11).process(Rx_sig);

%%%%%% Low-pass RX (PD, El. Connectors and Scope %%%%%%
rx_bwl = rx_bw_nyquist.*f_nyquist;
% rx_bwl = 80e9;
Rx_sig = Filter('filtdegree',4,"f_cutoff",rx_bwl,"fs",fdac*kover,"filterType",filtertypes.butterworth,"active",true).process(Rx_sig);

% %%%%%% Low-pass Scope %%%%%%
Lp_scpe = Filter('filtdegree',4,"f_cutoff",110e9,"fs",fadc,"filterType",filtertypes.butterworth,"active",true);

% Rx_sig.spectrum("displayname",'Analog Rx Spectrum','fignum',100,'normalizeTo0dB',1);

%%%%%% Scope %%%%%%
Scpe_sig = Scope("fsimu",fdac*kover,"fadc",fadc,...
    "delay",0,"fixed_delay",0,"filtertype",filtertypes.butterworth,...
    "samplingdelay",0,"rand_samplingdelay",0,"freq_offset",0,"samp_jitter",0,...
    "adcresolution",8,"quantbuffer",0.1,'block_dc',1,'lpf_active',1,'H_lpf',Lp_scpe).process(Rx_sig);

Scpe_sig_resampled = Scpe_sig.resample("fs_out",2*fsym);

[~, Scpe_cell, ~, found_sync] = Scpe_sig_resampled.tsynch("reference", Symbols, "fs_ref", fsym, "debug_plots", 1);

eq_    = EQ("Ne",[vnle_order1,vnle_order2,vnle_order3],"Nb",[dfe_order],"training_length",len_tr,"training_loops",5,"dd_loops",5,"K",2,"DCmu",mu_dc,"DDmu",[mu_ffe mu_dfe],"DFEmu",0.005,"FFEmu",0,"plotfinal",0,"ideal_dfe",1);
pf_    = Postfilter("ncoeff",pf_ncoeffs,"useBurg",1);
% mlse_  = MLSE_viterbi("duobinary_output",0,'M',M,'trellis_states',PAMmapper(M,0).levels);
mlse_  = MLSE("duobinary_output",0,'M',M,'trellis_states',PAMmapper(M,0).levels);

if duob_mode == db_mode.no_db

    % FFE or VNLE
    [eq_signal_sd, eq_noise] = eq_.process(Scpe_cell{1}, Symbols);
    
    % Hard decision on VNLE output
    eq_signal_hd = PAMmapper(M, 0).quantize(eq_signal_sd);
    
    % Process through postfilter and MLSE
    [mlse_sig_sd,whitened_noise] = pf_.process(eq_signal_sd, eq_noise);
    mlse_.DIR = pf_.coefficients;
    mlse_sig_sd = mlse_.process(mlse_sig_sd,Symbols);
    
    
    % BER
    rx_bits = PAMmapper(M,0,"eth_style",0).demap(eq_signal_hd);
    [~,tot_err,ber_vnle,a] = calc_ber(rx_bits.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
    
    rx_bits = PAMmapper(M,0,"eth_style",0).demap(mlse_sig_sd);
    [~,tot_err,ber_mlse,a] = calc_ber(rx_bits.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);

elseif duob_mode == db_mode.db_precoded

    %%
    [EQ_sig, Noi] = eq_.process(Scpe_cell{1},Duobinary().encode(Symbols));

    showLevelHistogram(EQ_sig,Duobinary().encode(Symbols),"displayname",101);

    mim_decoded = Duobinary().decode(EQ_sig,"M",M);

    showLevelHistogram(mim_decoded,Symbols,"displayname",101);

    rx_bits_mim_decoded = PAMmapper(M,0,"eth_style",0).demap(mim_decoded);

    rx_bits_mim_decoded_.signal =  circshift(rx_bits_mim_decoded.signal,0);

    [~,~,ber_mim_decode,~]  = calc_ber(rx_bits_mim_decoded_.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);

    fprintf('BER mim: %.2e \n',ber_mim_decode);

    %%
    mlse_sig_hd = MLSE("DIR",[1,1],"duobinary_output",1,"M",M,"trellis_states",PAMmapper(M,0).levels).process(EQ_sig,Symbols);

    mlse_sig_hd_decoded = Duobinary().encode(mlse_sig_hd,"M",M);

    mlse_sig_hd_decoded = Duobinary().decode(mlse_sig_hd_decoded,"M",M);

    rx_bits_mlse_decoded = PAMmapper(M,0,"eth_style",0).demap(mlse_sig_hd_decoded);

    [~,errors_db_diff_precoded,ber_db_diff_precoded,a]  = calc_ber(rx_bits_mlse_decoded.signal,Tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);

    %%

end