CRC的matlab程序的问题

tingzhoubao

这是一个CRC校验码的生成函数。

function [ output ] = crc_add( input, crc_no )
k = size(input,2);
generator = zeros(1,crc_no+1);
output = zeros(1,k+crc_no);
switch  crc_no
case   3
generator = [1 0 1 1];
case   8
generator = [1 1 0 0 1 1 0 1 1];
case   12
generator = [1 1 0 0 0 0 0 0 0 1 1 1 1];
case   16
generator = [1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1];
case   24
generator = [1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 1 1];
otherwise
fprintf('\nPlease the number of crc bits should be 8 12 16 24\n');
end
output(1:k)=input;

for ii = 1:k
    if(output(1) == 1)
    output(1:crc_no+1) = mod((output(1:crc_no+1)+generator),2);
    end
    output = [output(2:end) output(1)];
end

output = [input output(1:crc_no)];

求教一下这个for ii = 1:k里面的ii什么意思啊

hnwulei

function [ output ] = crc_add( input, crc_no )
k = size(input,2);
generator = zeros(1,crc_no+1);
output = zeros(1,k+crc_no);
switch  crc_no
case   3
generator = [1 0 1 1];
case   8
generator = [1 1 0 0 1 1 0 1 1];
case   12
generator = [1 1 0 0 0 0 0 0 0 1 1 1 1];
case   16
generator = [1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1];
case   24
generator = [1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 1 1];
otherwise
fprintf('\nPlease the number of crc bits should be 8 12 16 24\n');
end
output(1:k)=input;

for ii = 1:k
     if(output(1) == 1)
     output(1:crc_no+1) = mod((output(1:crc_no+1)+generator),2);
     end
     output = [output(2:end) output(1)];
end

output = [input output(1:crc_no)];