1.m

维特比编解码

    SNRpBit = [4.5:.5:7]; linSNRpB = 10.^(SNRpBit(:).*0.1);
    M = 4; codeRate = 1/2; constlen = 7; k = log2(M); 
    dist = [10:16];  numErr = [36  0 211 0 1404 0 11633];
    expBER = 0.5.*erfc(sqrt(linSNRpB*codeRate));
    expVitBER = vitproberrdemo(expBER,dist,numErr);
    semilogy(SNRpBit,expVitBER,'g-');  xlabel('Eb/No per bit (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);