On the Performance Optimization of Two-Way Hybrid VLC/RF-Based IoT System Over Cellular Spectrum

This article investigates the system outage performance of a useful architecture of two-way hybrid visible light communication/radio-frequency (VLC/RF) communication using overlay mode of the cooperative cognitive radio network (CCRN). The demand of high data rate application can be fulfilled using VLC link and communication over a wide area of coverage with high reliability can be achieved through RF link. In the proposed architecture, cooperative communication between two licensed user (LU) nodes is accomplished via an aggregation agent (AA). AA can perform like a relay node and in return, it can access the LU spectrum for two-way communications with the Internet-of-Things (IoT) device. First, closed-form expressions of outage probability of both LU and IoT communication are established. On the basis of these expressions, optimization problems are formulated to achieve minimum outage probability of both LU and IoT network. The impacts of both VLC and RF system parameters on these systems outage probability and throughput are finally shown in simulation results.