0.m

维特比编解码

   cla;
    fig = gcf;
    set(fig, 'name',  'Convolutional Encoding and Viterbi Decoding Simulation Demonstration');
    sp = get(fig,'position');
    ss = get(0,'ScreenSize');
    fp1 = [ss(3)*0.55-sp(3)*0.55  ss(4)*.75-sp(4) sp(3)*1.32 sp(4)*1.43];
  %  if ichange == 0  & size(slideData.param,2) == 1; set(gcf,'position',fp1); end;  %?????????????????????????????/
    SNRpBit = [4.5:.5:7]; linSNRpB = 10.^(SNRpBit(:).*0.1);
    M = 4; codeRate = 1/2; constlen = 7; k = log2(M); 
    dist = [10:2:16];  numErr = [36 211 1404 11633];
    expBER = 0.5.*erfc(sqrt(linSNRpB*codeRate));
    expVitBER = vitproberrdemo(expBER,dist,numErr);
    semilogy(SNRpBit,expVitBER,'g-');  xlabel('Eb/No (dB)'); ylabel('BER');
    title('Performance for R=1/2, K=7 Conv. Code and QPSK with Hard Decision' ); grid on;
    axis([4 8 10e-7 10e-3]); legend('Union Bound',0);