Age of information of two-way data exchanging systems with power-splitting
Hu Cheng, Yunquan Dong · Journal of Communications and Networks · 2019
We consider a two-way data exchanging system consisting of an access point and a smart device. The access point has a constant power supply and the smart device does not. The access point simultaneously transmits information and energy to the smart device over block fading channels, with fixed powers ρ̅Pt and ρPt, respectively. The smart device receives data and energy at the same time, and stores the harvested energy in an energy buffer. Upon collecting enough energy, the smart device performs one block of transmission immediately. We investigate the timeliness and the efficiency of the system in terms of age of information (AoI) and data rate, respectively. We also investigate the trade-off between downlink communications and uplink communications by optimizing the weighted-sum average AoI and weighted-sum data rate. Moreover, we present the optimal power-splitting ratio ρ and the optimal weighting coefficient w explicitly or via efficient algorithm.