Transmit probability designs for wireless peer discovery with energy harvesting

This letter studies wireless peer discovery (WPD), which identifies the existence of neighbor nodes to establish link in systems where some nodes can harvest energy. In conventional WPD, each node operates in three different modes, namely, packet transmitting (Tx), data receiving, and sleeping modes. However, since the sleeping nodes neither transmit nor receive data, to make more efficient use of the resources, we consider a scenario where the sleeping nodes harvest energy from the signals radiated by the Tx nodes. First, we analyze the average number of discovered peers (ADP) and the amount of energy harvested per unit area as a function of the node densities. Then, we examine the ADP performance by addressing an ADP maximizing problem under the energy harvesting constraints, which is difficult to solve due to non-convexity. To tackle the problem, we focus on the asymptotic performance in the interference-limited scenario and provide an insightful closed-form solution. Numerical simulations confirm that our solution achieves near-optimal performance over all levels of interference with reduced complexity.