Help me find out what I'm doing wrong in this project

1 次查看（过去 30 天）

Cameron 2014-4-15

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/125778-help-me-find-out-what-i-m-doing-wrong-in-this-project

评论： Walter Roberson 2014-4-15

My assignment is to make a monte carlo simulation of a binary code of +/- 3 volts going through Gaussian noise and then to determine the bit error probability and signal to noise ratio and plot them vs each other. However when I run my program and get my plot it looks completely random and there is no noticeable trend or curve. I have my code done and I know it is at least half right because my BEPs were working fine before. If anyone sees what I am doing wrong I would love some input.

close all;clear all;clc;
sigma = 1;
Tb = zeros(1,100000);
Tv = zeros(1,100000);
Rb = zeros(1,100000);
BEP = zeros(1,100);
MSTv = zeros(1,100);
MSN = zeros(1,100);
SNR = zeros(1,100);
SNRdb = zeros(1,100);
n = 1;
while n <= 100
Tr = rand(1,100000);
i = 1;
while i <= 100000
      if Tr(1,i) >= 0.5
          Tb(1,i) = 1;
      else
          Tb(1,i) = 0;
      end
      i = i + 1;
end
Tbbins = [0 1];
Tbcounts = hist(Tb,Tbbins);
j = 1;
while j <= 100000
      if Tr(1,j) >= 0.5
          Tv(1,j) = 3;
      else
          Tv(1,j) = -3;
      end
      j = j + 1;
end
N = sigma * randn(1,100000);
R = Tv + N;
k = 1;
while k <= 100000
      if R(1,k) > 0
          Rb(1,k) = 1;
      else
          Rb(1,k) = 0;
      end
      k = k + 1;
end
errors = 0;
m = 1;
while m <= 100000
      if Rb(1,m) ~= Tb(1,m)
          errors = errors + 1;
      end
      m = m + 1;
end
BEP(1,n) = errors / 100000;
MSTv(1,n)= var(Tv) + (mean(Tv)*mean(Tv));
MSN(1,n) = var(N) + (mean(N)*mean(N));
SNR(1,n) = MSTv(1,n)/MSN(1,n);
SNRdb(1,n) = 10 * log10(SNR(1,n));
n = n + 1;
end
figure(1)
semilogy(SNRdb,BEP,'m-<', 'linewidth' ,2.0);
axis tight