Jointly Decoded Raptor Codes: Analysis and Design for the BIAWGN Channel

The authors are interested in the analysis and optimization of Raptor codes under a joint decoding framework, that is, when the precode and the fountain code exchange soft information iteratively. They develop an analytical asymptotic convergence analysis of the joint decoder, derive an optimization method for the design of efficient output degree distributions, and show that the new optimized distributions outperform the existing ones, both at long and moderate lengths. They also show that jointly decoded Raptor codes are robust to channel variation: they perform reasonably well over a wide range of channel capacities.