On the Capacity Region of the Gaussian MAC with Batteryless Energy Harvesting Transmitters
The authors consider the two-user additive Gaussian Multiple Access Channel (MAC) where the transmitters communicate by using energy harvested from nature. Energy arrivals of the users are i.i.d. in time, and for any given time, they are distributed according to a joint distribution. Energy arrivals cause time variations for the amplitude constraints of the users. They first consider the static amplitude constrained Gaussian MAC and prove that the boundary of the capacity region is achieved by discrete input distributions of finite support. When both of the transmitters are equipped with no battery, Shannon strategies applied by users provide an inner bound for the capacity region.