Energy minimization in two-way relay networks with digital network coding

In a two-way wireless relay network, two nodes communicate with each other through a relay, and throughput is enhanced by the relay transmitting a linear combination of the messages received from the two sources either at the bit level (digital network coding) or the signal level (analog network coding). In this paper, we solve for the fraction of time resources allocated to each transmission mode in a DNC-based two-way relay network that minimizes total energy while ensuring queue stability at all nodes, for a given pair of random packet arrival rates. We also provide a queueing analysis of the relaying protocol designed.