How do you find the parity matrix of a generator matrix?
Definition. Formally, a parity check matrix H of a linear code C is a generator matrix of the dual code, C⊥. This means that a codeword c is in C if and only if the matrix-vector product Hc⊤ = 0 (some authors would write this in an equivalent form, cH⊤ = 0.) to be a codeword of C.
How does LDPC work?
LDPC Decoding Algorithm
The decoding algorithms work by exchanging messages between the check and variable nodes. These messages contain a value that is proportional to the probability or the “belief” in the “correctness” of the received bit.