%?This?program?simulates?the?bit-error-rate?（BER）?performance?of?OSTBC
%?with?L=4?antennas?over?the?frequency?flat?Rayleigh?block?fading?channel?
%?The?code?is?developed?for?real?orthogonal?design?code?rate?1/2;
%?modulation-?16?QAM?with?gray?coding?resulting?in?2?bits/sec/Hz.

%?by?Samat?Shabdanov?February?2007?e-mail:shabdanov@yahoo.com




%16?QAM?constellation
x=[-3?-3?-3?-3???-1?-1?-1?-1??3?3?3??3????1?1?1??1??];
y=[3??1??-3?-1????3??1?-3?-1??3?1?-3?-1???3?1?-3?-1?];

Qam=x+y*i;
Es=10;?%average?constellation?energy?for?d=2;

index=1;

%set?SNR?step
step=4;

%?SNR?range?is?here
for?SNR=4:step:20
????
%number?of?bit?errors?set?to?zero
count=0;


%number?of?iterations
N=10^4;
if?SNR==20?N=3*10^4;?end;?%?increase?for?higher?SNR
?
????
for?it=1:N
????
%generate?16?bits?uniformly?distributed?
A=round（rand（116））;

%?TX?symbols
s1=Qam（bi2de（A（1:4）‘left-msb‘）+1）;
s2=Qam（bi2de（A（5:8）‘left-msb‘）+1）;
s3=Qam（bi2de（A（9:12）‘left-msb‘）+1）;
s4=Qam（bi2de（A（13:16）‘left-ms