The encoding algorithm of non-binary quasi-cyclic LDPC cycle codes on tanner graph

A low-density parity-check (LDPC) code of column weight of 2 is known as an LDPC cycle code. In this paper, we study the encoding algorithm about a type of non-binary quasi-cyclic LDPC cycle codes. The position of parity check symbols is located firstly through parity check equations. Then, we show that these parity check symbols can be calculated linearly through the corresponding Tanner graph. It turns out that the decoder can be used as the encoder.