On the error exponent to redundancy ratio of interactive encoding and decoding

The concept of error exponent to redundancy ratio (EERR) of interactive encoding and decoding (IED), as well as Slepian-Wolf coding (SWC), is defined and investigated in this paper. The EERR of universal IED is determined. In the non-universal coding case, it is shown that for any stationary ergodic source-side information pair, a two stage IED scheme with 3 rounds of interactions or less can be constructed such that its EERR ≥1. Meanwhile, for any memoryless source-side information pair, the EERR of SWC is strictly less than 1 in the region where the error exponent of SWC is determined. Furthermore, practical two stage IED schemes are proposed and implemented by using LDPC codes and Belief Propagation (BP) Decoding, and simulation shows that the error probability of the proposed two stage IED schemes is indeed significantly lower than that of SWC schemes.