怎么在matlab上设计不同码率，不同数据帧长的ldpc码的误比特率的程序

Matlab2008 以后的版本自带的就有，只需要自己设定生成矩阵即可。自己看一下帮助， Example H = dvbs2ldpc(3/5)spy(H)% Visualize the location of nonzero elements in H. henc = fec.ldpcenc(H)hdec = fec.ldpcdec(H)

sigm=0.1:0.1:5

ber=zeros(size(sigm))

for l=1:100

for w=1:length(sigm)

i=load('H.txt')

a=i(:,1)

b=i(:,2)

a=a+1

b=b+1

H=zeros(130,260)

idx=sub2ind(size(H),a',b')

H(idx)=1%generate the H matrix

x=zeros(1,260)

y=2*x-1

z=y+sigm(w)*randn(1,260)

p1=ones(1,260)./(1+exp(-2*z./sigm(w)))

p0=1-p1

qij1=H.*repmat(p1,130,1)

qij0=H.*repmat(p0,130,1)%intial step

for i=1:100

prdct=ones(130,1)

rji0=zeros(size(qij1))

tqij1=ones(size(qij1))-2*qij1

for i=1:130

for j=1:260

if tqij1(i,j)~=0

prdct(i)=prdct(i)*tqij1(i,j)

else

prdct(i)=prdct(i)

end

end

end

for i=1:130

for j=1:260

if tqij1(i,j)~=0

rji0(i,j)=prdct(i)/tqij1(i,j)

else

rij0(i,j)=0

end

end

end

rji0=1/2+1/2*rji0

rji1=1-rji0%horizontal step

prdct1=ones(1,260)

for j=1:260

for i=1:130

if rji1(i,j)~=0

prdct1(j)=prdct1(j)*rji1(i,j)

else

prdct1(j)=prdct1(j)

end

end

end

QQ1=p1.*prdct1

prdct0=ones(1,260)

for j=1:260

for i=1:130

if rji0(i,j)~=0

prdct0(j)=prdct0(j)*rji0(i,j)

else

prdct0(j)=prdct0(j)

end

end

end

QQ0=p0.*prdct0

k=ones(size(QQ1))./(QQ1+QQ0)

Q0=k.*QQ0

Q1=k.*QQ1

prdct2=ones(1,260)

qqij0=zeros(size(qij0))

for j=1:260

for i=1:130

if rji0(i,j)~=0

prdct2(j)=prdct2(j)*rji0(i,j)

else

prdct2(j)=prdct2(j)

end

end

end

for j=1:260

for i=1:130

if rji0(i,j)~=0

qqij0(i,j)=prdct2(j)/rji0(i,j)

else

qqij0(i,j)=0

end

end

end

qqqij0=repmat(p0,130,1).*qqij0

prdct3=ones(1,260)

qqij1=zeros(size(qij1))

for j=1:260

for i=1:130

if rji1(i,j)~=0

prdct3(j)=prdct3(j)*rji1(i,j)

else

prdct3(j)=prdct3(j)

end

end

end

for j=1:260

for i=1:130

if rji1(i,j)~=0

qqij1(i,j)=prdct3(j)/rji1(i,j)

else

qqij1(i,j)=0

end

end

end

qqqij1=repmat(p1,130,1).*qqij1

kk=ones(size(qij0))./(qqqij0+qqqij1)

qij0=kk.*qqqij0

qij1=kk.*qqqij1%vertical step

zz=(sign(Q1-Q0)+1)/2%decide the code should be either 1 or 0

if rem(zz*H',2)==0

break

end %calculate the syndrome

end

ber(w)=length(find(zz))/(260+ber(w))

end

end

snr=ones(size(sigm))./sigm

ber=ber./(ones(size(ber))*100)

plot(20*log(snr),ber,'*-')

xlabel('SNR')

ylabel('BER')

我自己编的，用SPA解码，循环一百次观察信噪比和误码率的关系，复杂度非常高，我是菜鸟。

你好，很高兴为你解答

I=input('I=')

k=0.1.*(I<10)+0.05.*(I>10&I<20)+0.02.*(I>20)

I=25

k

=

0.0200

如有其他问题，可以继续追问，您的采纳是我前进的动力！

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