4.m

维特比编解码

    constlen = [7]; codegen = [171 133];  tblen = 32; codeRate = 1/2;
    trel = poly2trellis(constlen, codegen);
    [msg_enc_bi] = convenc(msg_orig, trel);
	numEncPlot = numPlot ./ codeRate; tEnc = [0:numEncPlot-1] * codeRate;
	stem(tEnc, msg_enc_bi(1:length(tEnc)),'rx');
	axis([ min(tEnc) max(tEnc) -0.2 1.2]);  xlabel('Time'); ylabel('Amplitude'); 
    title('Binary Symbols After Convolutional Encoding');