function[err_rate]=converPe(snr_in_dB,signal)
%噪聲功率
E=1;
snr=10^(snr_in_dB/10);
sgma=sqrt((E/snr)/2);
%G,k
G=[1 0 0 1 1;1 1 0 1 1];
k=1;
%編碼
    u=viterbi_encoder(G,k,signal);
%經信道加高斯燥聲
u=2*u-1;
u=sign(u+sgma*randn(size(u))+eps);
u=(u+1)/2;
%解碼
	[rev_sig,survivor_state,cumulated_metric]=viterbi_decoder(G,k,u);
%誤碼率
    err_rate=(length(find(signal~=rev_sig)))/length(signal);