  The lifetime and the sustainability of the wireless sensor networks (WSNs)
can be increased with energy harvesting transmitters utilizing optimum packet
scheduling. On the other hand, WSNs are observed to collect spatially or
temporally correlated data which should be taken into account for the optimum
packet scheduling in an energy harvesting system. However, the solutions
available for 2-user multiple-access channel (MAC) systems with energy
harvesting transmitters do not consider the common data or the correlation
among the data. In this paper, optimal packet scheduling for energy harvesting
2-user Gaussian MAC with common data is achieved by assuming deterministic
knowledge of the data and energy packets, i.e., offline solution. The optimum
departure region is found by using Karush- Kuhn-Tucker (KKT) conditions
generalizing the solutions obtained for the MAC without common data. An
efficient iterative backward water-filling algorithm is defined. The optimum
solution is numerically compared with the case of no scheduling, uniform power
scheduling and the previous solutions defined for the MAC without common data
by showing the improvement obtained with the optimization.
