Q-LDPCA based distributed coding for asymmetrical correlated non-binary sources

Distributed coding is a new paradigm for compressing correlated distributed sources, based on Slepian-Wolf and Wyner-Ziv theorem. This scheme is appropriate for wireless sensor network and distributed video coding. In this paper, we address the problem of coding two correlated non-binary sources with asymmetrical statistical dependency using the q-ary low-density parity-check accumulate (Q-LDPCA) codes. On one hand the use of Q-LDPCA codes in the proposed system makes coding without converting non-binary sources to binary bits feasible, and thus it overcomes the reduction in correlation caused by conversion. On the other hand it makes coding rate varying adaptively with correlation of the correlated sources with asymmetrical statistical dependency, so it is suitable for many practical applications of distributed coding where the correlated sources are highly non-ergodic. Experiment shows that the proposed system performs better than coding by binary LDPC code with conversion first.