www.pudn.com > MODULATION.RAR > qam16.m, change:2001-11-30,size:2780b


% Program 3-21 
% qam16 
% 
% Simulation program to realize 16QAM transmission system 
% 
% Programmed by H.Harada and R.Funada 
% 
 
%******************** preparation part ************************************* 
 
sr=256000.0; % Symbol rate 
ml=4;        % ml:Number of modulation levels (BPSK:ml=1, QPSK:ml=2, 16QAM:ml=4) 
br=sr .* ml; % Bit rate 
nd = 1000;    % Number of symbols that simulates in each loop 
ebn0=6;      % Eb/N0 
IPOINT=8;    % Number of oversamples 
 
%********************** Filter initialization   ************************** 
 
irfn=21;                  % Number of taps 
alfs=0.5;                 % Rolloff factor 
[xh] = hrollfcoef(irfn,IPOINT,sr,alfs,1);   %Transmitter filter coefficients  
[xh2] = hrollfcoef(irfn,IPOINT,sr,alfs,0);  %Receiver filter coefficients  
 
%************************** START CALCULATION ******************************* 
 
nloop=100;  % Number of simulation loops 
 
noe = 0;    % Number of error data 
nod = 0;    % Number of transmitted data 
 
for iii=1:nloop 
     
%*************************** Data generation ******************************** 
 
	data1=rand(1,nd*ml)>0.5; 
 
%*************************** 16QAM Modulation ******************************** 
 
	[ich,qch]=qammod(data1,1,nd,ml); 
	[ich1,qch1]= compoversamp(ich,qch,length(ich),IPOINT);  
	[ich2,qch2]= compconv(ich1,qch1,xh);  
 
%**************************** Attenuation Calculation *********************** 
	 
    spow=sum(ich2.*ich2+qch2.*qch2)/nd; 
	attn=0.5*spow*sr/br*10.^(-ebn0/10); 
	attn=sqrt(attn); 
 
%********************** Fading channel ********************** 
 
  % Generated data are fed into a fading simulator 
  %  [ifade,qfade]=sefade(ich2,qch2,itau,dlvl,th1,n0,itnd1,now1,length(ich2),tstp,fd,flat); 
   
  % Updata fading counter 
  %  itnd1 = itnd1+ itnd0; 
 
%********************* Add White Gaussian Noise (AWGN) ********************** 
	 
    [ich3,qch3]= comb(ich2,qch2,attn);% add white gaussian noise 
	[ich4,qch4]= compconv(ich3,qch3,xh2); 
 
	sampl=irfn*IPOINT+1; 
	ich5 = ich4(sampl:IPOINT:length(ich4)); 
	qch5 = qch4(sampl:IPOINT:length(ich4)); 
         
%**************************** 16QAM Demodulation ***************************** 
	 
    [demodata]=qamdemod(ich5,qch5,1,nd,ml); 
 
%******************** Bit Error Rate (BER) **************************** 
	 
    noe2=sum(abs(data1-demodata)); 
	nod2=length(data1); 
	noe=noe+noe2; 
	nod=nod+nod2; 
 
	fprintf('%d\t%e\n',iii,noe2/nod2); 
end % for iii=1:nloop     
 
%********************** Output result *************************** 
 
ber = noe/nod; 
fprintf('%d\t%d\t%d\t%e\n',ebn0,noe,nod,noe/nod); 
fid = fopen('BERqam.dat','a'); 
fprintf(fid,'%d\t%e\t%f\t%f\t\n',ebn0,noe/nod,noe,nod); 
fclose(fid); 
 
%******************** end of file ***************************