qpskspacetimemain.m

空时编码源代码

clear all; clc;

% Number of state; change here:
% Use 4, 8, 16, 32, 64, 128, or 256
nrState = 4;

% Signal to Noise Ratio in dB
SNRindB = [8 10 12 14 16];

% Number of frame
N = 10000; 

% Number of data per frame
D = 130;

% The state generator matrices
% Number of state is limited to 256

switch nrState
   case {4}
      G = [2 1 0 0;0 0 2 1];
   case {8}
      G = [2 2 1 0 0;2 0 0 2 1];
   case {16}
      G = [0 2 2 1 0 0;2 0 0 2 2 1];
   case {32}
      G = [2 3 2 2 1 0 0;2 3 1 0 0 2 1];   
   case {64}
      G = [2 2 3 2 1 2 0 0;1 2 2 3 0 0 1 2];
   case {128}
      G = [2 2 1 2 3 1 2 0 0;1 2 3 2 1 0 0 2 1];
   case {256}
      G = [2 3 2 1 3 1 1 2 0 0;1 3 2 1 2 2 0 0 2 1];
   otherwise
      disp ('Number of state must be 4, 8, 16, 32, 64, 128, 256!');
      break;
end

% Form the trellis and the binary map for decoding
[st1 st2 bin] = stTrellis(G);

% Generate simple flat fading channel  
ch = rand(2, N) + j*rand(2, N);

for i = 1:length(SNRindB),
   fprintf('SNR = %d\n', SNRindB(i));
   numOfErr = 0; ber = 0;

   for j = 1:N
      % Calling the main function, replace the function here if needed
      [err, rat] = sttc4PskUseMex(st1, st2, bin, nrState, G, D, ch(:, j), SNRindB(i));
      ber = ber + rat;
      if err == 1
         numOfErr = numOfErr + 1;            
      end
   end
   % Bit error rate
   berTot(i) = ber/N;
   % Frame error rate
   fer(i) = numOfErr/N;
end;

% Plot here...
semilogy(SNRindB, fer, '-o');
grid on;