%%%%% SETTINGS %%%%%%
useprbs = 1;
M   = 8;
randkey = 1;
fsym = 112e9;
viewresults = 0;

%%%%% Mapping %%%%%
M = 8;
data = 0:M-1;
bitpersymbol = log2(M);

%Bits
bits = int2bit(data,bitpersymbol, true);

%Integers
ints = bit2int(bits,bitpersymbol, true);

Tx_bits = Informationsignal(bits');
Digi_Mod = PAMmapper(M,0);
Symbols = Digi_Mod.map(Tx_bits);
moveitgray = Symbols.signal;

%Gray Symbol Mapping
matlabgray = pammod(ints,M,0,'gray');
scaling_factor = rms(unique(matlabgray));
matlabgray = matlabgray ./ scaling_factor;


%Demod 
moveitgray = moveitgray.* scaling_factor;
matlabgray = matlabgray .* scaling_factor;
ints_demap = pamdemod(matlabgray,M,0,'gray');

bits_demap = int2bit(ints_demap,bitpersymbol, true);

% for i = 1:M
%     fprintf('%d , %d , %d --> %d \n',bits(1,i),bits(2,i),bits(3,i),matlabgray(i));
% end
% 
% for i = 1:M
%     fprintf('%d , %d , %d --> %d \n',bits(1,i),bits(2,i),bits(3,i),moveitgray(i));
% end

scatterplot(matlabgray,1,0,'b*');
for k = 1:M
    text(real(matlabgray(k)),imag(matlabgray(k))+0.6,num2str(ints_demap(k)),"Color",[1 1 1]);

    text(real(matlabgray(k)),imag(matlabgray(k))-1.6,num2str(bits(:,k)),"Color",'blue');
    text(real(moveitgray(k)),imag(moveitgray(k))-3,num2str(bits(:,k)),"Color",'green');
end
axis([-M M -3 2])


symbols = bit2int(bitGroups',bitpersymbol, true);


%%%%% PRBS Generation in correct shape for Modulation Format %%%%%%
O = 10; %order of prbs
N = 2^(O-1); %length of prbs
[~,seed] = prbs(O,1); %initialize first seed of prbs
bitpattern=[];
if useprbs
    for i = 1:log2(M)
        [bitpattern(:,i),seed] = prbs(O,N,seed);
    end
else
    s = RandStream('twister','Seed',randkey);
    for i = 1:log2(M)
        bitpattern(:,i) = randi(s,[0 1], N, 1);
    end
end
if M == 6
    bitpattern = reshape(bitpattern,[],1);
    bitpattern = bitpattern(1:end-mod(length(bitpattern),5));
end

Tx_bits = Informationsignal(bitpattern);

%%%%% ACTUAL TEST: Back to Back Mapping: Bits -> Symbols and Symbols -> Bits  %%%%%%

Digi_Mod = PAMmapper(M,0);

symbols = bitMapper(bitpattern, M, 'PAM');


Symbols = Digi_Mod.map(Tx_bits);

Rx_bits = PAMmapper(M,0).demap(Symbols);


%%%%% VALIDATION: BER is required to be zero %%%%%%

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


%%%%% For User: Show Debug Info and Results %%%%%%

if viewresults 
    disp(['BER: ',sprintf('%.1E',ber),' - - PAM-',num2str(M)]);
    
    
    figure
    subplot(1,2,1)
    hold on
    title('Symbols Out')
    stairs(Symbols_tx.signal(1:100,1),'LineWidth',2,'DisplayName','Tx Symbols')
    legend
    grid
    subplot(1,2,2)
    u = unique(Symbols_tx.signal);
    scatter(0,u,'filled','o','LineWidth',2,'MarkerFaceColor',linspecer(1));
    grid
end