Study, Design, and Implementation of VLC With Angular Diversity Receiver for IoT Systems

This article presents the performance analysis of angular diversity receivers (ADRs) and proposes a novel ADR system for visible light communication (VLC) in Internet of Things (IoT) sensor networks. The numerical analysis applying the combining techniques indicates that any combination of ADR types and diversity techniques can enhance performance. Therefore, a frustum-type ADR is implemented in the experimental demonstration with the equal gain combining (EGC) for signal-to-noise (SNR) enhancement. The ADR and the transceiver’s analog front end (AFE) are designed and prototyped. The proposed ADR system shows a 4 dB increase in received SNR under two access points. The bit error rate (BER) is also improved, and the link coverage is more than doubled. Additionally, to show the feasibility of the IoT application, a real-time sensor network system using the ADR is demonstrated. This experimental duplex system indicates the benefits in a practical scenario by showing packet error rate (PER) and response time.