useprbs = 1;
M = 4;
randkey = 1;
datarate = 224e9;
fsym = round(datarate / log2(M)) ;

db_pre = 1;

Pform       = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rrc","pulselength",16,"rrcalpha",0.05);

[d,Symbols,Bits] = PAMsource(...
    "fsym",fsym,"M",M,"order",17,"useprbs",1,...
    "fs_out",fsym,...
    "applyclipping",0,"clipfactor",1.5,...
    "applypulseform",0,"pulseformer",Pform,...
    "randkey",1,...
    "db_precode",db_pre,"db_encode",0,...
    "mrds_code",0,"mrds_blocklength",512).process();

%%%CHANNEL

% s = RandStream('twister','Seed',2);
% start = 10000;
% burstwidth = 100;
% d_burst = d;
% for pos = start:start+burstwidth
%     lvls = 1.5 .*  PAMmapper(M,0).levels / rms(PAMmapper(M,0).levels);
%     d_burst.signal(pos) = d.signal(pos)+randn(s,1,1);
% end

d_resample = d.resample("fs_out",2.*fsym);

eq_ffe = FFE("epochs_tr",5,"epochs_dd",5,"len_tr",1024,"mu_dd",0.0004,"mu_tr",0,"order",25,"sps",2,"decide",1);
d_eq = eq_ffe.process(d_resample,Symbols);

% s = RandStream('twister','Seed',2);
% start = 10000;
% burstwidth = 100;
% d_burst = d_eq;
% for pos = start:start+burstwidth
%     lvls = 1.5 .*  PAMmapper(M,0).levels / rms(PAMmapper(M,0).levels);
%     d_burst.signal(pos) = d_eq.signal(pos)+randn(s,1,1);
% end
% 
% d_burst = PAMmapper(M,0).decide_pamlevel(d_burst);

if db_pre
    % Entschiedene Symbole codieren: d_DB(n) = d(n) + d(n-1)    (im Fall von PAM4 7 level [0 1 2 3 4 5 6])
    d_db = Duobinary().encode(d);
    
    % Entschiedene codierte Symbole decodieren: d_dec(n) = d_DB(n) mod4
    d_dec = Duobinary().decode(d_db);
else
    d_dec = d_burst;
end

% Vergleichen von b(n) und d_dec(n)
Rx_bits = PAMmapper(M,0).demap(d_dec);

Tx_bits = Bits;

[~,error_num,ber,error_pos] = calc_ber(Tx_bits.signal,Rx_bits.signal,"skip_front",0,"skip_end",0,"returnErrorLocation",1);

disp(['BER: ',sprintf('%.1E',ber),' - - PAM-',num2str(M)]);

figure(200)
clf
hold on
idxs = start-10:start+burstwidth+10;
scatter(idxs,d.signal(idxs),'DisplayName',['Orig Signal'],'Marker','o');
scatter(idxs,d_burst.signal(idxs),'DisplayName',['Error Signal'],'Marker','x');
scatter(idxs,d_dec.signal(idxs),'DisplayName',['EQ Signal'],'Marker','x');
yline(PAMmapper(M,0).thresholds,'HandleVisibility','off');
legend
ylim([-2 2])