sync_acquisition_tracking_algo2_dab_receiver_nctu.m

DAB transmitter, synchronization and receiver under development

clear all;
close all;
clc;

  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Program to generate the parameter h values
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
h=zeros(4,32);
h(1,2)=2;
h(1,7:8)=1;
h(1,9)=2;
h(1,13:14)=2;
h(1,15:16)=1;
h(2,2)=3;
h(2,3)=2;
h(2,4)=3;
h(2,6)=1;
h(2,7)=3;
h(2,9)=2;
h(2,10)=1;
h(2,11)=2;
h(2,12)=3;
h(2,13)=2;
h(2,14:15)=3;
h(3,4)=2;
h(3,6)=2;
h(3,7)=1;
h(3,8)=3;
h(3,9:10)=2;
h(3,12:13)=2;
h(3,15)=1;
h(3,16)=3;
h(4,2)=1;
h(4,3)=2;
h(4,4)=1;
h(4,6:7)=3;
h(4,8:9)=2;
h(4,10)=3;
h(4,11)=2;
h(4,12)=1;
h(4,13)=2;
h(4,14)=1;
h(4,15)=3;
h(4,16)=2;
h(1:4,17:32)=h(1:4,1:16);

null_symbol_duration=2656;
no_of_subcarriers_per_symbol=1536;
load ('freq_interleaving_12june.dat');
freq_deinterleaving_mod1 = reshape(freq_interleaving_12june,1,1536); 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Program to generate the Phase Reference Symbol
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% First af all generate the k', i and n arrays is needed

for k=1:1536
    switch k
    case 1  
        k_bis=1;i=0;n=1;
    case 33
        k_bis=33;i=1;n=2;
    case 65
        k_bis=65;i=2;n=0;
    case 97
        k_bis=97;
        i=3;
        n=1;
    case 129
        k_bis=129;
        i=0;
        n=3;
    case 161
        k_bis=161;
        i=1;
        n=2;
    case 193
        k_bis=193;
        i=2;
        n=2;
    case 225
        k_bis=225;
        i=3;
        n=3;
    case 257
        k_bis=257;
        i=0;
        n=2;
    case 289
        k_bis=289;
        i=1;
        n=1;
    case 321
        k_bis=321;
        i=2;
        n=2;
    case 353
        k_bis=353;
        i=3;
        n=3;
    case 385
        k_bis=385;
        i=0;
        n=1;
    case 417
        k_bis=417;
        i=1;
        n=2;
    case 449
        k_bis=449;
        i=2;
        n=3;
    case 481
        k_bis=481;
        i=3;
        n=3;
    case 513
        k_bis=513;
        i=0;
        n=2;
    case 545
        k_bis=545;
        i=1;
        n=2;
    case 577
        k_bis=577;
        i=2;
        n=2;
    case 609
        k_bis=609;
        i=3;
        n=1;
    case 641
        k_bis=641;
        i=0;
        n=1;
    case 673
        k_bis=673;
        i=1;
        n=3;
    case 705
        k_bis=705;
        i=2;
        n=1;
    case 737
        k_bis=737;
        i=3;
        n=2;
    case 769
        k_bis=769;
        i=0;
        n=3;
    case 801
        k_bis=801;
        i=3;
        n=1;
    case 833
        k_bis=833;
        i=2;
        n=1;
    case 865
        k_bis=865;
        i=1;
        n=1;
    case 897
        k_bis=897;
        i=0;
        n=2;
    case 929
        k_bis=929;
        i=3;
        n=2;
    case 961
        k_bis=961;
        i=2;
        n=1;
    case 993
        k_bis=993;
        i=1;
        n=0;
    case 1025
        k_bis=1025;
        i=0;
        n=2;
    case 1057
        k_bis=1057;
        i=3;
        n=2;
    case 1089
        k_bis=1089;
        i=2;
        n=3;
    case 1121
        k_bis=1121;
        i=1;
        n=3;
    case 1153
        k_bis=1153;
        i=0;
        n=0;
    case 1185
        k_bis=1185;
        i=3;
        n=2;
    case 1217
        k_bis=1217;
        i=2;
        n=1;
    case 1249
        k_bis=1249;
        i=1;
        n=3;
    case 1281
        k_bis=1281;
        i=0;
        n=3;
    case 1313
        k_bis=1313;
        i=3;
        n=3;
    case 1345
        k_bis=1345;
        i=2;
        n=3;
    case 1377
        k_bis=1377;
        i=1;
        n=0;
    case 1409
        k_bis=1409;
        i=0;
        n=3;
    case 1441
        k_bis=1441;
        i=3;
        n=0;
    case 1473
        k_bis=1473;
        i=2;
        n=1;
    case 1505
        k_bis=1505;
        i=1;
        n=1;
    end
% Now it's time to calculate the phase reference symbol!
% First of all the phi(k) phase is needed, so the "h" parameter
% has to be determinated.

    phi(k)=(pi/2)*(h(i+1,k-k_bis+1)+n);
    z(k)=exp(j*phi(k));
    if abs(real(z(k)))<1
        Phase_Reference(k)=j*imag(z(k));
    else
        Phase_Reference(k)=real(z(k));
    end
end
phase_ref_beginning= Phase_Reference;
% for m=-8:8
%     for n=0:15
%         r11_m(m+9,n+1)=phase_ref_beginning(1,n+1)*conj(phase_ref_beginning(1,mod(n+1+m+9,16)));
%     end
%     r1_m(1,m+9)=sum(r11_m(m+9,:));
% end
phase_ref_beginning=[phase_ref_beginning zeros(1,512)];
temp=[phase_ref_beginning(769:1536) phase_ref_beginning(1537:2048) phase_ref_beginning(1:768)];
phase_ref_beginning=temp;


NO_OF_DATA_BITS=768;
no_of_fibs_tx_frame=12;
no_of_CIFs_tx_frame=4;
punctured_data_bits=3072;
Tx_carriers_ofdm_symbol=1536;
freq_interleaved_bits=2048;
useful_symbol_duration=2048;
guard_interval=504;

%%%%%%%%%%%%Determining auto-correlation of TX PRS%%%%%%
   
%Loading real time data; Assume start of null symbol is unknown           
DAB_RX_Frame15=load('237_488MHz_IF2MHz_PAT1_80dB_1_updated_frame_cs4.dat');   %2552 samples per symbol; %2506 samples per symbol in the frame for core clock =system clock*4
DAB_RX_Frame15=DAB_RX_Frame15.';
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    %%%%%%%%%%%%%%%%  Null Symbol detection-Coarse timing estimation
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
nn1=length(DAB_RX_Frame15);
nn2=mod(nn1,32);
nn=nn1/32;%Number of blocks
mm=1;
for i=1:nn
    energy(i)=0;
    for ii=1:32
        energy(i)=energy(i)+((DAB_RX_Frame15(mm)*DAB_RX_Frame15(mm))/2);
        mm=mm+1;
    end
end

%%%%%%%%%%%%%%%%Algo 2%%%%%%%%%%%%%%%%%%%

start=0;low=0;threshold = 5000;count=0;
for i=2:nn
    if (i==3850)
        iii=0;
    end
    if low==0
        if (energy(i)<energy(i-1))
            start=1;
            low=1;
            threshold=energy(i-1)/10;
            startpos=i;
        else
            start=0;
        end
    else
        if (energy(i)<=threshold  && (energy(i)<=energy(i-1) ||( abs(energy(i)-energy(i-1)) <5000)  ) )
            start=start+1;
            if ((count <=2) && (count > 0))
                startpos=i;
            end
        else
            if (start > 250)
                count=count+1;%low=0;%startpos=0;
                if (count > 3)
                    start=0;low=0;startpos=0;
                else
                    start=start+1;
                end
            end
            
        end
    end

    if (start>=332)
        null_symbol_stop=10624;
        break;
    end
end

if (startpos>=2)
    if energy(startpos+1) > 500000
        Null_start_64=startpos;