conv_code_viterbi.rar_卷积码编码

t = poly2trellis([3 3],[4 5 7;7 4 2]); k = log2(t.numInputSymbols); msg = [1 1 0 1 1 1 1 0 1 0 1 1 0 1 1 1]; code = convenc(msg,t); tblen = 3; [d1 m1 p1 in1]=vitdec(code(1:end/2),t,tblen,'cont','hard') [d2 m2 p2 in2]=vitdec(code(end/2+1:end),t,tblen,'cont','hard',m1,p1,in1) [d m p in] = vitdec(code,t,tblen,'cont','hard') % The same decoded message is returned in d and [d1 d2]. The pairs m and % m2, p and p2, in and in2 are equal. Note that d is a delayed version of % msg, so d(tblen*k+1:end) is the same as msg(1:end-tblen*k). l=1000; data=randint(1,l); data_enc=convenc(data,t); tblen = 3; data_rx=awgn(data_enc,20,'measured'); for i=1:length(data_rx) if data_rx(i)>0.5 data_rx1(i)=1; else data_rx1(i)=0; end end [d m p in] = vitdec(data_rx1,t,tblen,'cont','hard'); d(7:l)-data(1:l-6) error=0; for i=1:l-6 if d(6+i)~=data(i) error=error+1; end end error