A simple method to construct LDPC codes based on projective planes

We consider a simple description of the incidence matrix of a projective plane over the field GF(q), using multiplication and addition tables of the finite field. Some basic properties of LDPC codes derived from such incidence matrices are discussed. Further, a class of LDPC codes of paper [1], derived from Reed-Solomon (RS) codes with two information symbols, is considered. By comparing these two classes, we give a simple equivalence proof for them.