Asymmetric spatially-coupled LDPC codes for burst erasure channels

The outstanding performance of Spatially-Coupled Low Density Parity Check(SC-LDPC) codes deteriorates due to burst erasures over the channels with memory. To improve the performance of SC-LDPC codes over burst erasure channels, an asymmetric spatial coupling structure is proposed where the variable nodes at the same position of the protograph are permitted to couple with check nodes with different coupling widths. According to the structural properties of the Asymmetric Spatially-Coupled LDPC (ASC-LDPC) codes, the characteristics of the stopping sets of the base matrices are analyzed. It is shown that the base matrix of an ASC-LDPC code possesses a longer span and a larger cardinality of the minimal stopping set than that of the conventional SC-LDPC code. Thus a longer single-burst erasure or more multiple-burst erasures can be corrected by ASC-LDPC codes. Simulation results show that the proposed asymmetric spatial coupling structure could improve the performance of SC-LDPC codes over both the single-burst erasure channels and multiple-burst erasure channels.