Network-coded rateless coding scheme in erasure multiple-access relay enable communications

This study proposes a novel adaptive network-coded rateless coding scheme for an erasure multiple-access relay system with two distributed sources and an asymmetric network topology. To increase transmission efficiency, a two-dimensional degree distribution, as part of network-coded relay protocol, is designed based on the AND-OR tree analysis technique. The degree distributions of rateless coding at the sources and network coding at the relay are optimised by the linear programming approach under asymmetric channel conditions. Simulation results demonstrate that the proposed scheme outperforms existing classical relay protocols under time-varying channel conditions, and achieves a significantly better performance.