Constraint Satisfaction Through GBP-Guided Deliberate Bit Flipping

Abstract

In this paper, we consider the problem of transmitting binary messages over data-dependent two-dimensional channels. We propose a deliberate bit flipping coding scheme that removes channel harmful configurations prior to transmission. In this method, user messages are encoded with an error correction code, and therefore the number of bit flips should be kept small not to overburden the decoder. We formulate the problem of minimizing the number of bit flips as a binary constraint satisfaction problem, and devise a generalized belief propagation guided method to find approximate solutions. Applied to a data-dependent binary channel with the set of 2-D isolated bit configurations as its harmful configurations, we evaluated the performance of our proposed method in terms of uncorrectable bit-error rate.