useprbs = 1;
M = 6;
randkey = 1;
datarate = 448e9;
fsym = round(datarate / log2(M)) ;

%%%%% PRBS Generation in correct shape for Modulation Format %%%%%%
O = 17; %order of prbs
N = 2^(O); %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);

Symbols_tx = PAMmapper(M,0).map(Tx_bits);
Symbols_tx.fs = fsym;

Symbols = Duobinary().precode(Symbols_tx);

Symbols = Duobinary().encode(Symbols);

Symbols = Duobinary().decode(Symbols);

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

[~,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(3);
clf
%sgtitle(['BER: ',num2str(ber),' // Error is at position: ',num2str(error_pos),''])
subplot(2,2,1)
hold on
title('First Bits')
stairs(Tx_bits.signal(1:100,1),'LineStyle','-','LineWidth',2,'DisplayName','Tx Bits');
stairs(Rx_bits.signal(1:100,1),'LineWidth',2,'DisplayName','Rx Bits','LineStyle',':')
legend

subplot(2,2,2)
title('Last Bits')
hold on
stairs(Tx_bits.signal(end-50:end,1),'LineStyle','-','LineWidth',2,'DisplayName','Tx Bits');
stairs(Rx_bits.signal(end-50:end,1),'LineWidth',2,'DisplayName','Rx Bits','LineStyle',':')
legend

subplot(2,2,3)
hold on
title('First Symbols Compare')
stairs(Symbols_tx.signal(1:100,1),'LineWidth',2,'DisplayName','Tx Symbols','LineStyle','-')
stairs(Symbols.signal(1:100,1),'LineStyle',':','LineWidth',2,'DisplayName','Rx Symbols');
legend

subplot(2,2,4)
hold on
title('Last Symbols Compare')
stairs(Symbols_tx.signal(end-50:end,1),'LineWidth',2,'DisplayName','Tx Symbols','LineStyle','-')
stairs(Symbols.signal(end-50:end,1),'LineStyle',':','LineWidth',2,'DisplayName','Rx Symbols');
legend