Simultaneous information and energy transfer in large-scale cellular networks with sleep mode

Energy harvesting from ambient radio frequency (RF) radiation is an efficient approach to provide wireless energy replenishment for mobile devices. At the same time, introducing active/sleep modes in base stations (BSs) is an effective method to save the energy consumption of cellular networks. However, the performance of the two techniques would be dependent and interact with each other if both of them were employed in cellular networks. In this paper, we analyze the performance and investigate the sleeping strategy design problem in the cellular network, in which the mobile devices have the capability of energy harvesting from the ambient RF signals. Specifically, using tools from stochastic geometry theory, we derive analytical expressions of the coverage probability and the harvested energy and show that they are both affected by the sleeping strategy. Then, we formulate a BSs power consumption minimization problem under the coverage probability and harvesting performance constraints. Finally, the optimal operating regime of the sleeping strategy is derived. Numerical results confirm the correctness of the analysis and show the effect of switching off BSs on both performance metrics.