function [out] = convencoder(din,trellis)
%卷積碼編碼器
%輸入：din {0,1}序列碼流
%      trellis  Matlab格式網格結構(可以用poly2trellis獲得)
%初態為0
curState = 0;
for k=1:length(din)
    d(k) = trellis.outputs( curState+1,din(k)+1 );
    curState = trellis.nextStates( curState+1, din(k)+1 );
end

N = floor( log2(trellis.numOutputSymbols) );
out = dec2bin(d,N)-48;
out = reshape(out',1,N*length(din));