Green Cognitive Internet of Things with Self Supply of Energy and Spectrum in Emergency Communications
Xin Liu, Xueyan Zhang · 2020
In the emergency scenario, wireless communication systems will face spectrum shortage and energy cut-off in case of infrastructure destruction. In this paper, a green cognitive Internet of Things (CIoT) with wireless energy harvesting (WEH) is proposed to share the spectrum licensed to primary user (PU) and harvest the radio frequency (RF) energy of PU's signal, in order to achieve self supply of energy and spectrum. Energy-efficient resource allocation is presented to maximize the average transmission rate of CIoT while guaranteeing the energy saving requirements. The underlay and overlay spectrum access models for CIoT with WEH are described, in which the energy-efficient resource allocations are formulated as joint optimization problems that can be solved using alternating direction optimization (ADO) and Karush-Kuhn-Tucker (KKT) conditions. Results show that the CIoT with WEH can consume less power to achieve larger transmission rate.