Highly SNR uniformity and power efficient model for indoor VLC based on DCO-GFDM modulation

Abstract Innovation of new light emitting diodes (LEDs) distribution for indoor visible light communication (VLC) systems is necessary to mitigate challenges like signal-to-noise ratio (SNR) uniformity. In addition, creating proper lighting in indoor environments is essential for occupants’ comfort and energy efficiency, where uniform illuminance is needed. This article proposes optimum LEDs distribution to find higher illuminance uniformity based on various semi-angles of light half power and analyzes the best SNR uniformity. The higher SNR uniformity improves user experience by ensuring consistent data transmission quality throughout the room and maintaining a lower bit error rate (BER). The proposed VLC model comprises 16 illuminance units with 30 × 30 LED chips placed in the ceiling of a standard room (5 × 5 × 3 m 3 ). Considering the reflections, the receiver’s delay spread is relatively high due to this higher number of transmitters. This VLC model is examined using a flexible advanced modulation based on multiple subcarriers in different scenarios to mitigate delay spread issues. Optical generalized frequency division multiplexing (OGFDM) modulation is utilized due to its high spectral efficiency and inter-symbol interference reduction. Employing the same power as the standard VLC model with 4 LED transmitters reveals a notable improvement in illuminance and SNR uniformities, power received, and illuminance and SNR values fulfilled by the proposed model.