Multi-Detection for Internet of Everything Enabled Smart City Indoor Positioning: A Comparison of JML and SIC in VLC-NOMA Systems

Abstract

Visible Light Communication (VLC) is emerging as a key enabling technology for Internet of Everything (IoE) and smart city infrastructures, where precise indoor localization is required for connected devices, smart buildings, and intelligent services. However, inter-user interference remains a critical challenge in multiuser Non-Orthogonal Multiple Access (NOMA)-based VLC positioning systems. This paper presents a comparative analysis of Joint Maximum Likelihood (JML) and Successive Interference Cancellation (SIC) detection techniques in a 4-QAM VLC-NOMA setup employing index modulation. Through Monte Carlo simulations, the impact of different power allocation ratios and signal-to-noise ratios (SNR) on Bit Error Rate (BER) is evaluated for both near and far users. Additionally, positioning accuracy is analyzed to assess suitability for IoE-enabled smart city applications such as asset tracking, indoor navigation, and smart infrastructure monitoring. Results show that JML consistently achieves lower BER and higher reliability across all SNR values, especially under strong interference conditions, while SIC provides a computationally efficient but suboptimal alternative. The findings highlight the trade-off between detection performance and complexity, offering insights for designing scalable VLC-based indoor positioning systems for future smart city environments.