Irregular Marker Codes for Insertion/Deletion-AWGN Channels

A concatenated coding scheme employing an irregular marker code as the inner code is designed to improve the ability of correcting insertions/deletions. In this scheme, bits associated with each marker symbol are allocated to the symbol of the LDPC code non-uniformly. Since the non-binary marker symbol at the irregular position provides reliable forward/backward quantities, significant amount of insertions and deletions can be detected and corrected by the presented method. Simulation results show that the proposed scheme has an improved performance with only a very small penalty in coding rate compared with the traditional regular marker code.