LTE-matlab-problem-BER

Hello there i finally managed to finish my project about LTE system!!!But i have a really big BER around 50%....Can anyone help me solve it???
If yes please tell me an e-mail to send him my m-file!!!

Thanks in advance!!!:razz::razz:

post code on pastebin and paste that link here and I'll see if i can help!

SNR=10;

bits=2048;
a1=randint(bits,1);

t = poly2trellis([5 4],[23 35 0; 0 5 13]);
a2=convenc(a1,t);

a3=pskmod(a2,4);

bit2=length(a3);
a41=reshape(a3,bit2/512,512);

for i=1:bit2/512
a4(i,=ifft(a41(i,,512);
a5(i,=[a4(i,end-512/4+1:end) a4(i,];%cyclic prefix
end

s=a5;

Ray1=raylrnd(0.6,1,640);
Log1=lognrnd(0.5,0.5,1,640);
Ray2=raylrnd(0.6,1,640);
Log2=lognrnd(0.5,0.5,1,640);
Ray3=raylrnd(0.6,1,640);
Log3=lognrnd(0.5,0.5,1,640);
Ray4=raylrnd(0.6,1,640);
Log4=lognrnd(0.5,0.5,1,640);

h0=Ray1+Log1;
h1=Ray2+Log2;
h2=Ray3+Log3;
h3=Ray4+Log4;

for line=1:2:bit2/512
r1(line,=h0.*s(line,+h1.*s(line+1,;
r1(line+1,=h2.*s(line,+h3.*s(line+1,;
r2(line,=-h0.*s(line,+h1.*s(line+1,;
r2(line+1,=-h2.*s(line,+h3.*s(line+1,;
end

r11=awgn(r1,SNR,'measured');
r22=awgn(r2,SNR,'measured');

for i=1:2:bit2/512
rec(i,=r11(i,;
rec(i+1,=r22(i+1,;
end


for i=1:bit2/512
b1(i,=[rec(i,end-512/4:end) rec(i,];
b2(i,=fft(b1(i,,512);
end


b3=pskdemod(b2,4);

b4=reshape(b3.',1,bit2);

tb=3;

b5=vitdec(b4,t,tb,'trunc','hard');

b5=b5.';

BitErrors=sum(b5~=a1)
rate=BitErrors/length(a1)

plot(SNR,rate)


That's my code with BER 50%(~2%)

Hi placebo69,

The problem with BER is probably, that you have used rayleigh channel, In order to get good BER you should do channel estimation and equalization once you receive the data.