conv_encoder.m

该文件夹为空时块码－卷积码级联系统的仿真程序

function encoded_bits=conv_encoder(infobits, biting_pattern)
% 802.16 OFDMA Convolutional Encoder, coding rate 1/2
% constraint length k=7
% generator: G1=171oct for X, G2=133oct for Y

L=length(infobits);
encoded_bits=zeros(1,2*L);

% Initial encoder register for tail biting
if biting_pattern=='zero',
    encoder_reg=zeros(1,6);
else
    encoder_reg=fliplr(infobits(end-5:end));
end

for loop=1:L
    encoded_bits(2*loop-1)=mod(infobits(loop)+encoder_reg(1)+encoder_reg(2)+encoder_reg(3)+encoder_reg(end),2); % X-G1
    encoded_bits(2*loop)=mod(infobits(loop)+encoder_reg(2)+encoder_reg(3)+encoder_reg(5)+encoder_reg(end),2); % Y-G2
    encoder_reg=[infobits(loop),encoder_reg(1:5)];
end