M=2;
Tsym=0.2;
Tsample=0.01;
EbNoVec=[0:2:12];
TVec=[1000 1000 1000 15000 20000 100000 100000]*Tsym;
maxNumErrs=100;
maxNumBits=1e6;

for n=1:length(EbNoVec);
    Tmax=TVec(n);
    EbNo=EbNoVec(n);
    sim('mpsk');
    BERVec(n,:)=grayBER;
    EbNoLineare=realpow(10,EbNo/10);
    TheoryVec(n,:)=[erfc(sqrt(3*EbNoLineare)*sin(pi/M))]/log2(M);
end;

semilogy (EbNoVec,BERVec(:,1),'*-',TheoryVec(:,1),'o-');
legend ('Bit error rate','Theoretical BER');
xlabel('Eb/No (dB)');
ylabel('Bit Error Probability');
title('Bit Error Probability');

The ERROR MESSAGE is:
??? Error using ==> semilogy
String argument is an unknown option.

Error in ==> run_2psk at 18
semilogy (EbNoVec,BERVec(:,1),'*-',TheoryVec(:,1),'o-');

.... but i don't understan ... why ??? ... please ... help me ...

"Francesco De Marianis" <francesco_demarianis@hotmail.com> wrote in message <hmisua$o0u$1@fred.mathworks.com>...
* snip *
> semilogy (EbNoVec,BERVec(:,1),'*-',TheoryVec(:,1),'o-');

> The ERROR MESSAGE is:
> ??? Error using ==> semilogy
> String argument is an unknown option.

You miss an argument!

semilogy (x1, y1,'*-', ADD_AN_ARGUMENT_HERE_x2, y2,'o-');

See the help of SEMILOGY

hth
Jos