Optimal resource allocation for multiple access channel with conferencing links and a shared renewable energy source

This paper investigates the optimal resource allocation for the Gaussian multiple access channel (MAC) with conferencing links, where the two transmitters could talk to each other via some wired rate-limited channels. Moreover, the two transmitters are assumed to be powered by a shared energy harvester, and a deterministic energy-harvesting (EH) model is adopted by assuming that the energy arrival times and the corresponding harvested amounts are non-causally known prior to transmissions. We formulate a continuous-time power allocation problem to characterize the maximum departure region over a finite time horizon. By exploiting its convexity, this problem is simplified as a discrete-time problem and the optimal solution is obtained. In particular, it is shown that there exists a certain maximum possible transmission rate (the capping rate) at one of the transmitters. Finally, we compare the performance of the optimal offline algorithm against that of the online one.