PROPOSAL TITLE OF PROPOSAL : Concatenated Coding Schemes for Bit

The proposed research program addresses a key signal processing issue for BPMR, i.e., the correction of written-in errors introduced by the BPMR channel. To this end, we will investigate concatenated coding schemes for an insertiondeletion-substitution (IDS) channel that models the residual write errors that the channel decoder sees after the detection phase in a BPMR system. Our concatenated coding scheme will comprise of an outer LDPC code and an inner convolutional code. The inner code will be designed to have maximal free distance for a given constraint length and rate, in terms of the Levenshtein distance metric. The outer code will be designed to approach the capacity of the serial concatenation of the inner encoder, IDS channel and inner decoder. By employing a suitably modified MAP decoder for the inner code, the performance of our concatenated coding schemes will be analyzed under turbo iterative decoding, with the objective of establishing the maximum code rates that can be used given the probability of an insertion/deletion and the maximum burst error length in the vicinity of these error events.