% 64QAM/OFDM system

% The number of subcarrier is 8
clear all
% THe IFFT input SubCarrier is 8+Zero(0) = 8
% USEFUL DATA : 51.840Mbps(STM-0)
% CODING : 26/27
% Coded data : (51.840*27/26) 53.83385Mbps
% 64QAM mapping Data : (53.83385/6) = 8.972308Msps

% subcarrier spacing is (8.972308/8) = 1.1215385MHz

% OFDM signal BW (=Subcarr_spacing * 8), (=8.972308MHz) 3dB point
% OFDM signal 99% PWR BW : 9.5330772MHz((=Subcarr_spacing * 17/16)
% Nyquist frequency is 2*8.972308 >= 17.944616MHz
% Hence the sampling interval (ts) = 1/(17.944616MHz) = 55.727. . . ns

%%%%%%%%%% Initialization %%%%%%%%%%%%%%%%%%%%%
% Number=100;
Number = input('input the number of ofdm signal data : ');
Num_car = input('input the number of ofdm subcarrier : ');
% Num_car = 32;
Zero_Num = 0;
SubCarrier = Num_car + Zero_Num;
d_rate = 51.84*10^6;             % required information bit rate
c_rate = 26/27;				   % code rate
coded_rate = d_rate/c_rate;  % coded symbol rate

SymbolRate = coded_rate/(log2(64));   % 64QAM symbol rate  %%犬牢秦 焊辨 繳杭 飯撈飄綽 函煉規僥俊 蝶扼 促福促.%%

SubCarrierSpacing = SymbolRate/Num_car;    % subcarrier spacing
OF_Carrierdur = 1/SubCarrierSpacing;
OF_Symdur = OF_Carrierdur*SubCarrier;
iff_N = Num_car;%32;          % This must be carefully selected to prevent spectral aliasing
ts = 1/(OF_Carrierdur); 
fs = 1/ts;		% this must be larger than the OFDM BW*2
df = 2*10^3;      % required frequency resolution
delta=0.1;         % equalizer step size
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
bPath_Num = 2; %input ('Enter is Path of Number(1~2): ');

%64 QAM Generator
QAM_Data = QAM_Generator(Num_car*Number);
disp('End of QAM_Generator'); 

%IFFT
IFFTData= Radix2IFFT(QAM_Data,SubCarrier);
%Plot_frequence(IFFTData);%2 graph
disp('End of Radix2IFFT');

%Insert Zero
for st=1:SubCarrier*Number,
   IFFTDataWithZero(st*2-1)=IFFTData(st);
   IFFTDataWithZero(st*2)=0;
end;

%Filter
for loop=0:31,
   
alpha=input ('Enter is fading Depth (0~1) : '); %0.9;
FadingDelay=16*10^-9;
SampleDelay=input ('Enter is SampleDelay : ');
SampleDelay=10^-9*SampleDelay;
delay=SampleDelay;
FilteredData=Dig_Filter(IFFTDataWithZero,delay);
delay=FadingDelay+SampleDelay;
DelayedData=DelayFilter(IFFTDataWithZero,delay);
disp('End of Dig_Filter');
delay=FadingDelay+SampleDelay;
MultiPathData=FilteredData-alpha*DelayedData;
%Spectrum Display
%Spec_Display(FilteredData);
%Spec_Display(DelayedData);
Spec_Display(MultiPathData);                 %%% 犬牢竅扁 %%%

for j=0:Number-1,
   OFDM_Dat= IFFTData(SubCarrier*j+1:SubCarrier*(j+1));
   pt(SubCarrier*j+1:SubCarrier*(j+1))=fft(OFDM_Dat);
end;
%Constel(QAM_Data,SubCarrier);

for j=0:Number-1,
   for k=0:SubCarrier-1,
      SamplingPoint=j*SubCarrier+k;
      pop(k+1)=FilteredData(16+SamplingPoint*2);
   end;
   FFTData(j*SubCarrier+1:(j+1)*SubCarrier)=fft(pop);
   
   % Equalizer Part
   d=1;
   mapping=[ 7*d + i*7*d;
      -7*d + i*7*d;
      7*d - i*7*d;
      -7*d - i*7*d];
   for sub=1:SubCarrier,
      if j==0,
         estimated_c(sub)=1;                                     
      end
      %k=sub;
      y_k=FFTData(j*SubCarrier+sub);
      z_k(sub)=estimated_c(sub)*y_k;                      % equalizer out put
      for b=1:4,
         metrics(sub,b)=(real(z_k(sub))-real(mapping(b,1)) ).^2 + (imag(z_k(sub))-imag(mapping(b,1))).^2;
      end;
      % khryu=[];
      [min_metrics decs]=min(metrics(sub,:));
      khryu=mapping(decs);
      e_k(sub)=khryu-z_k(sub);
      estimated_c(sub)=estimated_c(sub)+delta*e_k(sub)*conj(y_k);   % coefficients update
      mse(sub)=e_k(sub)^2;
   end
   kh_k(j*SubCarrier+1:(j+1)*SubCarrier)=z_k;
   %lms=[lms mse(dis)];

end;
% Constel(kh_k,SubCarrier);

for j=0:Number-1,
   for k=0:SubCarrier-1,
      SamplingPoint=j*SubCarrier+k;
      pop(k+1)=MultiPathData(16+SamplingPoint*2);
   end;
   FFTData(j*SubCarrier+1:(j+1)*SubCarrier)=fft(pop);
   
   % Equalizer Part
   d=1;
   mapping=[ 7*d + i*7*d;
      -7*d + i*7*d;
      7*d - i*7*d;
      -7*d - i*7*d];
   for sub=1:SubCarrier,
      if j==0,
         estimated_c(sub)=1;                              
      end
      %k=sub;
      y_k=FFTData(j*SubCarrier+sub);
      z_k(sub)=estimated_c(sub)*y_k;                      % equalizer out put
      for b=1:4,
         metrics(sub,b)=(real(z_k(sub))-real(mapping(b,1)) ).^2 + (imag(z_k(sub))-imag(mapping(b,1))).^2;
      end;
      % khryu=[];
      [min_metrics decs]=min(metrics(sub,:));
      khryu=mapping(decs);
      e_k(sub)=khryu-z_k(sub);
      estimated_c(sub)=estimated_c(sub)+delta*e_k(sub)*conj(y_k);   % coefficients update
      mse(sub)=e_k(sub)^2;
   end
   kh_k(j*SubCarrier+1:(j+1)*SubCarrier)=z_k;
   %lms=[lms mse(dis)];
     
end;
% Constel(FFTData,SubCarrier);            % original constellation
Constel(kh_k,SubCarrier);                      % equalized signal constellation

pause;
for j=0:Number-1,
   for sub=1:SubCarrier,
      %k=sub;
      y_k=FFTData(j*SubCarrier+sub);
      z_k(sub)=estimated_c(sub)*y_k;                      % equalizer out put
   end
   kh_k(j*SubCarrier+1:(j+1)*SubCarrier)=z_k;
end;

% Constel(FFTData,SubCarrier);            % original constellation
Constel(kh_k,SubCarrier);                      % equalized signal constellation

end;