MLE in OFDM.SOS!

Hi All!
I have written a section of codes according to the J.J. van de Beek's <ML
Estimation of time and frequence offset in OFDM system>, but the result is
wrong. I do not know why, I hope someone can help me,thanks! 

clear all;

%********************** preparation part ***************************

para=128;   % Number of parallel channel to transmit (points)
fftlen=128; % FFT length
noc=1024;    % Number of carrier
nd=6;       % Number of information OFDM symbol for one loop
ml=2;       % Modulation level : QPSK
sr=250000;  % Symbol rate
br=sr.*ml;  % Bit rate per carrier
gilen=128;   % Length of guard interval (points)
ebn0=3;     % Eb/N0
SNR=15;     % ENR

%************************** transmitter *********************************

%************************** Data generation **************************** 

seldata=rand(1,para*nd*ml)>0.5;  %  rand : built in function
M=length(seldata)/noc;
%****************** Serial to parallel conversion ***********************

paradata=reshape(seldata,para,nd*ml); %  reshape : built in function

%************************** QPSK modulation *****************************


[ich,qch]=qpskmod(paradata,para,nd,ml);
kmod=1/sqrt(2); %  sqrt : built in function
ich1=ich.*kmod;
qch1=qch.*kmod;

%******************* IFFT ************************

x=ich1+qch1.*i;
y=ifft(x);      %  ifft : built in function
ich2=real(y);   %  real : built in function
qch2=imag(y);   %  imag : built in function

%********* cyclic perfix insertion **********

[ich3,qch3]= giins(ich2,qch2,fftlen,gilen,nd);

%***************** AWGN addition ********* 

ich4=AWGN(ich3,SNR);
qch4=AWGN(qch3,SNR);

rx=ich4+qch4.*i;

%****************** Calculate gamma(m) & PI(m) *******************

gamma =zeros(M,noc);
lamda =zeros(M,noc);
pii =zeros(M,noc);
ro = SNR/(SNR+1);
e=0.25;



%sampling_rx=[zeros(1,1) rx zeros(1,2*noc+gilen-1)];
for n=1:M
 for theta=1:noc
      
  %       sampling_rx(n,:)=[rx(n,1:theta) real(rx(n,:))
rx(n,1:noc-theta)]; 
         sampling_rx=[rx(n,1:theta) rx(n,:) rx(n,1:noc-theta)];   
        % sampling_rx(n,:)=[zeros(1,theta) rx(n,:) zeros(1,noc-theta)];
         
       for k=theta:theta+gilen-1
                %equation 2-(6),2-(7)                
                gamma(n,theta)=
gamma(n,theta)+sampling_rx(n,k)*conj(sampling_rx(n,k+noc));
                pii(n,theta)=pii(n,theta)+abs(sampling_rx(n,k))^2 +
abs(sampling_rx(k+noc))^2;
       end
        gamma(n,theta)
       pii(n,theta)=0.5*pii(n,theta);
        
        %equation 2-(5)
      
lamda(n,theta)=abs(gamma(n,theta))*cos(2*pi*e+angle(gamma(n,theta))) -
ro*pii(n,theta);
        
    end
end


figure(8);
%subplot(4,1,1);
plot(abs(gamma(1,:)))
%subplot(4,1,2);
%plot(pii(1,:))
%subplot(4,1,3);
%plot(abs(lamda));
%subplot(4,1,4);
%plot(real(sampling_rx(1,:)))

figure(9);
plot(lamda(1,:))

hey mib,
           one thing i didnt understand

is M = (128*6*2)/1024 = (12)/(8) = (3)/(2)

if so,
is this right in matlab ??

gamma = zeros(3/2,1024);  % what does this generate
lamda = zeros(3/2,1024);  % what does this generate

 gamma =zeros(M,noc);
lamda =zeros(M,noc);

where 128 = para;
           6 = ml;
           2 = nd;
          noc = 1024;


mib wrote:
> Hi All!
> I have written a section of codes according to the J.J. van de Beek's <ML
> Estimation of time and frequence offset in OFDM system>, but the result is
> wrong. I do not know why, I hope someone can help me,thanks!
>
> clear all;
>
> %********************** preparation part ***************************
>
> para=128;   % Number of parallel channel to transmit (points)
> fftlen=128; % FFT length
> noc=1024;    % Number of carrier
> nd=6;       % Number of information OFDM symbol for one loop
> ml=2;       % Modulation level : QPSK
> sr=250000;  % Symbol rate
> br=sr.*ml;  % Bit rate per carrier
> gilen=128;   % Length of guard interval (points)
> ebn0=3;     % Eb/N0
> SNR=15;     % ENR
>
> %************************** transmitter *********************************
>
> %************************** Data generation ****************************
>
> seldata=rand(1,para*nd*ml)>0.5;  %  rand : built in function
> M=length(seldata)/noc;
> %****************** Serial to parallel conversion ***********************
>
> paradata=reshape(seldata,para,nd*ml); %  reshape : built in function
>
> %************************** QPSK modulation *****************************
>
>
> [ich,qch]=qpskmod(paradata,para,nd,ml);
> kmod=1/sqrt(2); %  sqrt : built in function
> ich1=ich.*kmod;
> qch1=qch.*kmod;
>
> %******************* IFFT ************************
>
> x=ich1+qch1.*i;
> y=ifft(x);      %  ifft : built in function
> ich2=real(y);   %  real : built in function
> qch2=imag(y);   %  imag : built in function
>
> %********* cyclic perfix insertion **********
>
> [ich3,qch3]= giins(ich2,qch2,fftlen,gilen,nd);
>
> %***************** AWGN addition *********
>
> ich4=AWGN(ich3,SNR);
> qch4=AWGN(qch3,SNR);
>
> rx=ich4+qch4.*i;
>
> %****************** Calculate gamma(m) & PI(m) *******************
>
> gamma =zeros(M,noc);
> lamda =zeros(M,noc);
> pii =zeros(M,noc);
> ro = SNR/(SNR+1);
> e=0.25;
>
>
>
> %sampling_rx=[zeros(1,1) rx zeros(1,2*noc+gilen-1)];
> for n=1:M
>  for theta=1:noc
>
>   %       sampling_rx(n,:)=[rx(n,1:theta) real(rx(n,:))
> rx(n,1:noc-theta)];
>          sampling_rx=[rx(n,1:theta) rx(n,:) rx(n,1:noc-theta)];
>         % sampling_rx(n,:)=[zeros(1,theta) rx(n,:) zeros(1,noc-theta)];
>
>        for k=theta:theta+gilen-1
>                 %equation 2-(6),2-(7)
>                 gamma(n,theta)=
> gamma(n,theta)+sampling_rx(n,k)*conj(sampling_rx(n,k+noc));
>                 pii(n,theta)=pii(n,theta)+abs(sampling_rx(n,k))^2 +
> abs(sampling_rx(k+noc))^2;
>        end
>         gamma(n,theta)
>        pii(n,theta)=0.5*pii(n,theta);
>
>         %equation 2-(5)
>
> lamda(n,theta)=abs(gamma(n,theta))*cos(2*pi*e+angle(gamma(n,theta))) -
> ro*pii(n,theta);
>
>     end
> end
>
>
> figure(8);
> %subplot(4,1,1);
> plot(abs(gamma(1,:)))
> %subplot(4,1,2);
> %plot(pii(1,:))
> %subplot(4,1,3);
> %plot(abs(lamda));
> %subplot(4,1,4);
> %plot(real(sampling_rx(1,:)))
> 
> figure(9);
> plot(lamda(1,:))

OH. sorry!
noc=128
Thanks,again!

>hey mib,
>           one thing i didnt understand
>
>is M = (128*6*2)/1024 = (12)/(8) = (3)/(2)
>
>if so,
>is this right in matlab ??
>
>gamma = zeros(3/2,1024);  % what does this generate
>lamda = zeros(3/2,1024);  % what does this generate
>
> gamma =zeros(M,noc);
>lamda =zeros(M,noc);
>
>where 128 = para;
>           6 = ml;
>           2 = nd;
>          noc = 1024;
>
>
>mib wrote:
>> Hi All!
>> I have written a section of codes according to the J.J. van de Beek's
<ML
>> Estimation of time and frequence offset in OFDM system>, but the result
is
>> wrong. I do not know why, I hope someone can help me,thanks!
>>
>> clear all;
>>
>> %********************** preparation part ***************************
>>
>> para=128;   % Number of parallel channel to transmit (points)
>> fftlen=128; % FFT length
>> noc=1024;    % Number of carrier
>> nd=6;       % Number of information OFDM symbol for one loop
>> ml=2;       % Modulation level : QPSK
>> sr=250000;  % Symbol rate
>> br=sr.*ml;  % Bit rate per carrier
>> gilen=128;   % Length of guard interval (points)
>> ebn0=3;     % Eb/N0
>> SNR=15;     % ENR
>>
>> %************************** transmitter
*********************************
>>
>> %************************** Data generation
****************************
>>
>> seldata=rand(1,para*nd*ml)>0.5;  %  rand : built in function
>> M=length(seldata)/noc;
>> %****************** Serial to parallel conversion
***********************
>>
>> paradata=reshape(seldata,para,nd*ml); %  reshape : built in function
>>
>> %************************** QPSK modulation
*****************************
>>
>>
>> [ich,qch]=qpskmod(paradata,para,nd,ml);
>> kmod=1/sqrt(2); %  sqrt : built in function
>> ich1=ich.*kmod;
>> qch1=qch.*kmod;
>>
>> %******************* IFFT ************************
>>
>> x=ich1+qch1.*i;
>> y=ifft(x);      %  ifft : built in function
>> ich2=real(y);   %  real : built in function
>> qch2=imag(y);   %  imag : built in function
>>
>> %********* cyclic perfix insertion **********
>>
>> [ich3,qch3]= giins(ich2,qch2,fftlen,gilen,nd);
>>
>> %***************** AWGN addition *********
>>
>> ich4=AWGN(ich3,SNR);
>> qch4=AWGN(qch3,SNR);
>>
>> rx=ich4+qch4.*i;
>>
>> %****************** Calculate gamma(m) & PI(m) *******************
>>
>> gamma =zeros(M,noc);
>> lamda =zeros(M,noc);
>> pii =zeros(M,noc);
>> ro = SNR/(SNR+1);
>> e=0.25;
>>
>>
>>
>> %sampling_rx=[zeros(1,1) rx zeros(1,2*noc+gilen-1)];
>> for n=1:M
>>  for theta=1:noc
>>
>>   %       sampling_rx(n,:)=[rx(n,1:theta) real(rx(n,:))
>> rx(n,1:noc-theta)];
>>          sampling_rx=[rx(n,1:theta) rx(n,:) rx(n,1:noc-theta)];
>>         % sampling_rx(n,:)=[zeros(1,theta) rx(n,:)
zeros(1,noc-theta)];
>>
>>        for k=theta:theta+gilen-1
>>                 %equation 2-(6),2-(7)
>>                 gamma(n,theta)=
>> gamma(n,theta)+sampling_rx(n,k)*conj(sampling_rx(n,k+noc));
>>                 pii(n,theta)=pii(n,theta)+abs(sampling_rx(n,k))^2 +
>> abs(sampling_rx(k+noc))^2;
>>        end
>>         gamma(n,theta)
>>        pii(n,theta)=0.5*pii(n,theta);
>>
>>         %equation 2-(5)
>>
>> lamda(n,theta)=abs(gamma(n,theta))*cos(2*pi*e+angle(gamma(n,theta))) -
>> ro*pii(n,theta);
>>
>>     end
>> end
>>
>>
>> figure(8);
>> %subplot(4,1,1);
>> plot(abs(gamma(1,:)))
>> %subplot(4,1,2);
>> %plot(pii(1,:))
>> %subplot(4,1,3);
>> %plot(abs(lamda));
>> %subplot(4,1,4);
>> %plot(real(sampling_rx(1,:)))
>> 
>> figure(9);
>> plot(lamda(1,:))
>
>