Dynamic Decode-and-Forward Relaying Using Raptor Codes
Dynamic Decode-and-Forward (DDF) is a version of decode-and-forward relaying in which the duration of the listening phase at relays is not fixed. In this paper, the authors investigate half-duplex DDF relaying based on rateless codes. The use of rateless codes allows relays to autonomously switch from listening to the source node to transmitting to the destination node. They first revisit different signal combining strategies applied at the destination node, namely energy and information combining known from literature, and propose a new combining method which they refer to as mixed combining. The different combining methods give rise to different achievable rates, i.e., constrained channel capacities, for which they provide analytical expressions.