frame_head.m

定义了通信中帧格式

function y = frame_head(x,data_length,k)
% x=[0 0 1 1 0 0 1 1];
% data_length=4;
% k=2;
backer_code(2,:) = [1 1 0 0 0 0 0 0 0 0 0 0 0];
backer_code(3,:) = [1 1 0 0 0 0 0 0 0 0 0 0 0];
backer_code(4,:) = [1 1 1 0 0 0 0 0 0 0 0 0 0];
backer_code(5,:) = [1 1 1 0 1 0 0 0 0 0 0 0 0];
backer_code(7,:) = [1 1 1 0 0 1 0 0 0 0 0 0 0];
backer_code(11,:) = [1 1 1 0 0 0 1 0 0 1 0 0 0];
backer_code(13,:) = [1 1 1 1 1 0 0 1 1 0 1 0 1];
temp_code = backer_code(k,1:k);
if sum(temp_code) == 0
   error('Input the Wrong Length of the Backer code')
end
framehead = [temp_code ~temp_code temp_code];
m = length(x);
if rem(m,data_length) > 0
  x=[x,zeros(size(1:data_length-rem(m,data_length)))];
end
n=length(x)/data_length;
num=length(framehead)+data_length;
for i=1:n    
    y((1+(i-1)*num):(i*num)) = [framehead x((1+(i-1)*data_length):(data_length+(i-1)*data_length))]; 
end
n = data_length -rem(m,data_length);
y = y(1:(end-n));