Error Floor and Decoding with Message Scaling for Accumulator-Based and LDPC Codes

In this paper, we study the error floor of accumulator-based codes under iterative decoding and attempt to improve the performance. It is shown that the associated error events are often due to detectable errors, and proper design of an interleaver is effective for such weakness of the code. Subsequently, a simple modification of iterative decoding by scaling messages is shown to effectively achieve lower error probabilities in the error floor region, with an extension to LDPC codes.