fixed point ldpc decoder

[electronical]

Hello,i am working on LDPC Decoder,
I have problems with fixed point. 1.how way do i define fixed point?
2.In papers, I read that the size of memories which use for saving Min_1st, Min_2nd and sum variable nodes is define equals of bits used for input LLR?

 

[ammassk]

I didnt understand what is your problem. Fixed point numbers, you can find out using matlab and store in an LUT.