MIMO VLC System With Aggregated Angular Diversity Photoresistor Receivers for Misalignment Compensation
Jaeyeong Ha, Jaehyun Park, Yang Huang
TL;DR: This paper proposes a high-reliability MIMO VLC system architecture employing spatially separated receiver units, where each unit utilizes an analog-aggregated angular diversity receiver with a multi-directional photoresistor array, and introduces a current mirror-based analog pre-conditioning circuit.
Visible light communication (VLC) has emerged as a promising technology for next-generation wireless communication systems, particularly for indoor positioning and massive Internet of Things (IoT) networks, due to its immunity to electromagnetic interference and high directivity. However, this inherent directivity renders VLC systems highly susceptible to transmitter-receiver misalignment, which significantly degrades communication reliability. This paper proposes a high-reliability MIMO VLC system architecture employing spatially separated receiver units, where each unit utilizes an analog-aggregated angular diversity receiver (ADR) with a multi-directional photoresistor array. To overcome the inherent non-linearity of low-cost photoresistors, we introduce a current mirror-based analog pre-conditioning circuit. This circuit ensures linear mapping of aggregated optical signals, enabling the application of optimal linear estimation techniques such as MMSE in cost-effective hardware. Experimental results using a hardware prototype demonstrate that the proposed architecture achieves an 80% reduction in bit error rate under misaligned conditions compared to conventional single-sensor systems. Our approach provides a scalable, low-cost solution tailored for low-rate robust signaling, device identification, and indoor positioning beaconing in massive IoT networks.