Structural analysis of array-based non-binary LDPC codes

Motivated by the superior performance of array-based non-binary low-density parity-check (LDPC) codes, we study in this paper their structural properties by combinational and graphical techniques. The main results are summarized as follows. First, we show that there exist codewords with symbol weight six and seven in array-based non-binary LDPC (NBLDPC) codes with column weight 3. Second, we characterize the graphical substructures induced by weight-6 and weight-7 codewords. Finally, we carry out comparisons to confirm the performance advantage of array-based NBLDPC codes.