www.pudn.com > MIMO-OFDM(simulinkANDmatlab).rar > ofdmce.m, change:2001-11-29,size:5614b


% Program 4-8 
% ofdmce.m 
% 
% Simulation program to realize OFDM transmission system 
% 
% Programmed by T.Yamamura and H.Harada 
% 
% GI CE GI data GI data...(data 6symbols) 
% (CE: Chanel estimation symbol, GI Guard interval) 
% 
 
%********************** preparation part *************************** 
 
para=52;    % Number of parallel channel to transmit (points) 
fftlen=64;  % FFT length 
noc=53;     % Number of carriers 
nd=6;       % Number of information OFDM symbol for one loop 
knd=1;      % Number of known channel estimation (CE) OFDM symbol 
ml=2;       % Modulation level : QPSK 
sr=250000;  % OFDM symbol rate (250 ksyombol/s) 
br=sr.*ml;  % Bit rate per carrier 
gilen=16;   % Length of guard interval (points) 
ebn0=3;     % Eb/N0 
 
%%%%%%%%%%%%% fading initialization %%%%%%%%%%% 
 
tstp=1/sr/(fftlen+gilen); % Time resolution 
itau=[0];       % Arrival time for each multipath normalized by tstp  
dlvl1=[0];      % Mean power for each multipath normalized by direct wave. 
n0=[6];	        % Number of waves to generate fading n0(1),n0(2) 
th1=[0.0];      % Initial Phase of delayed wave 
itnd1=[1000];   % set fading counter        	 
now1=1;         % Number of directwave + Number of delayed wave 
fd=150;         % Maximum Doppler frequency 
flat=0;         % Flat or not (see ofdm_fading.m) 
itnd0=nd*(fftlen+gilen)*20; % Number of fading counter to skip  
 
%************************** main loop part ************************** 
 
nloop=1000;  % Number of simulation loops 
 
noe = 0;    % Number of error data 
nod = 0;    % Number of transmitted data 
eop=0;      % Number of error packet 
nop=0;      % Number of transmitted packet 
 
%************************** transmitter ***************************** 
for iii=1:nloop 
    
seridata=rand(1,para*nd*ml)>0.5;  %  DC=0 
 
paradata=reshape(seridata,para,nd*ml); %size(51  *  nd*ml) 
 
%-------------- ml modulation ----------------  
 
[ich,qch]=qpskmod(paradata,para,nd,ml); 
kmod=1/sqrt(2); 
ich=ich.*kmod; 
qch=qch.*kmod; 
 
% CE data generation 
kndata=zeros(1,fftlen); 
kndata0=2.*(rand(1,52)>0.5)-1; 
kndata(2:27)=kndata0(1:26); 
kndata(39:64)=kndata0(27:52); 
ceich=kndata; % CE:BPSK 
ceqch=zeros(1,64); 
 
%------------- data mapping (DC=0) ----------- 
 
[ich1,qch1]=crmapping(ich,qch,fftlen,nd); 
 
ich2=[ceich.' ich1]; % I-channel transmission data 
qch2=[ceqch.' qch1]; % Q-channel transmission data 
 
%------------------- IFFT  ------------------- 
 
x=ich2+qch2.*i; 
y=ifft(x); 
ich3=real(y); 
qch3=imag(y); 
 
%---------- Gurad interval insertion --------- 
 
fftlen2=fftlen+gilen; 
[ich4,qch4]= giins(ich3,qch3,fftlen,gilen,nd+1); 
 
%---------- Attenuation Calculation ---------- 
 
spow=sum(ich4.^2+qch4.^2)/nd./para; 
attn=0.5*spow*sr/br*10.^(-ebn0/10); 
attn=sqrt(attn); 
 
 
%********************** fading channel ******************************  
%If you would like to simulate performance under fading, please remove "*" 
%from the following four sentenses 
%[ifade,qfade,ramp,rcos,rsin]=sefade(ich4,qch4,itau,dlvl1,th1,n0,itnd1,now1,length(ich4),tstp,fd,flat); 
%itnd1 = itnd1+itnd0;  % Updata fading counter 
%ich4=ifade; 
%qch4=qfade; 
 
%***************************  Receiver  ***************************** 
%--------------- AWGN addition ---------------  
[ich5,qch5]=comb(ich4,qch4,attn); 
 
%----Perfect fading compensation for one path fading ---- 
%If you would like to simulate performance under perfect compensation, please remove "*" 
%from the following four sentenses 
%ifade2=1./ramp.*(rcos(1,:).*ich5+rsin(1,:).*qch5); 
%qfade2=1./ramp.*(-rsin(1,:).*ich5+rcos(1,:).*qch5); 
%ich5=ifade2; 
%qch5=qfade2; 
 
%----------- Guard interval removal ---------- 
[ich6,qch6]= girem(ich5,qch5,fftlen2,gilen,nd+1); 
 
%------------------  FFT  -------------------- 
rx=ich6+qch6.*i; 
ry=fft(rx); 
ich7=real(ry); 
qch7=imag(ry); 
 
%-------------- Fading compensation by CE symbol -------------- 
% 
%If you would like to simulate performance under CE-based compensation, please remove "*" 
%in this area 
% 
 
% preparation known CE data 
%ce=1; 
%ice0=ich2(:,ce); 
%qce0=qch2(:,ce); 
 
% taking CE data out of received data 
%ice1=ich7(:,ce); 
%qce1=qch7(:,ce); 
 
% calculating reverse rotation  
%iv=real((1./(ice1.^2+qce1.^2)).*(ice0+i.*qce0).*(ice1-i.*qce1)); 
%qv=imag((1./(ice1.^2+qce1.^2)).*(ice0+i.*qce0).*(ice1-i.*qce1)); 
 
% matrix for reverse rotation 
%ieqv1=[iv iv iv iv iv iv iv]; 
%qeqv1=[qv qv qv qv qv qv qv]; 
 
% reverse rotation 
%icompen=real((ich7+i.*qch7).*(ieqv1+i.*qeqv1)); 
%qcompen=imag((ich7+i.*qch7).*(ieqv1+i.*qeqv1)); 
%ich7=icompen; 
%qch7=qcompen; 
 
%---------- CE symbol removal ---------------- 
 
ich8=ich7(:,knd+1:nd+1); 
qch8=qch7(:,knd+1:nd+1); 
 
% DC and pilot data removal 
[ich9,qch9]=crdemapping(ich8,qch8,fftlen,nd); 
 
%----------------- demoduration -------------- 
 
ich10=ich9./kmod; 
qch10=qch9./kmod; 
[demodata]=qpskdemod(ich10,qch10,para,nd,ml);    
 
%--------------  error calculation  ---------- 
 
demodata1=reshape(demodata,1,para*nd*ml); 
noe2=sum(abs(demodata1-seridata)); 
nod2=length(seridata); 
 
 
% calculating PER 
if noe2~=0 
   eop=eop+1; 
else 
   eop=eop; 
end    
   eop; 
   nop=nop+1; 
    
% calculating BER 
noe=noe+noe2; 
nod=nod+nod2; 
 
fprintf('%d\t%e\t%d\n',iii,noe2/nod2,eop); 
    
end 
 
per=eop/nop; 
ber=noe/nod; 
 
%********************** Output result *************************** 
 
fprintf('%f\t%e\t%e\t%d\t%d\n',ebn0,ber,per,nloop,fd); 
   
fid = fopen('BERofdmce.dat','a'); 
fprintf(fid,'%f\t%e\t%e\t%d\t\n',ebn0,ber,per,nloop); 
fclose(fid); 
 
%******************** end of file ***************************