Age-of-Information Minimization in Two-User Multiple Access Channel with Energy Harvesting

We consider the uplink of an energy harvesting (EH) wireless sensor network (WSN) with two users communicating with one common fusion center (FC), proposing resource allocation algorithms aiming to minimize the average age of information (AoI) for two different scenarios, i.e., frequency-division multiple access (FDMA) and time-division multiple access (TDMA). Furthermore, the convexity of a lower bound of AoI is shown in this manuscript, facilitating the proposed allocation algorithms to find the optimal point with low complexity. Numerical results show the equivalency between the brute-force search and proposed algorithms and that FDMA can achieve the smaller AoI than TDMA over fading channels.