Energy-Efficient Coexistence of LiFi Users and Light Enabled IoT Devices

Owing to power limitations and hardware constraints of the Internet of Things (IoT) device, it requires simple, low power, low complex, energy-efficient communication technology. In contrast, LiFi users require high data rates and reliable connectivity. Motivated by the diverse requirements of these heterogeneous users, this paper proposes novel green communication schemes that can be used for the coexistence of LiFi users and light communication (LC) enabled IoT devices under a common LiFi access point. The proposed coexistence schemes utilize the amalgamation of wavelength division multiplexing, OFDMA, Hartley transform based DCO-OFDM (DCO-OFDM ^{\mathrm {H}} ), null DC element, interleaved subcarrier mapping, modified data sequence to achieve concurrent interference-free, low complex and reliable communication. Additionally, as the multiple access (MA) techniques affect the choice of modulation techniques and overall performance in the system. Therefore, this paper includes an analytical delay and throughput framework to corroborate the decision of an appropriate combination of MA and modulation techniques in the coexistence scheme. This paper presents a comprehensive analysis of the proposed coexistence schemes against conventional DCO-OFDM ^{\mathrm {H}} coexistence schemes based on various performance metrics. The results suggest that the proposed DL and UL coexistence schemes reduce the complexity and increase the energy efficiency at the user's and device's terminals.