Performance analysis of DCO-OFDM over precoded massive MIMO VLC channel

Abstract

Visible light communication (VLC) has emerged as a viable supplement to existing RF based communication systems. To enhance the achievable rate of VLC systems, the use of massive arrays of light emitting diodes (LEDs) and photodetectors (PDs) have been recently proposed, resulting in a massive multiple input multiple output (m-MIMO) VLC system. Furthermore, orthogonal frequency division multiple access (OFDM) has been explored for mitigating the inter-symbol interference due to limited modulation-bandwidth of the LED, and reflections from walls. One of the drawbacks of m-MIMO over VLC channels is the ill-conditioned nature of the VLC channel. To mitigate this, a zero-forcing successive interference cancellation (ZF-SIC) receiver with SVD (singular-value decomposition-based index precoding has been proposed recently. In this work, we propose and analyze the performance of minimum mean squared error (MMSE) based receiver for DC-biased O-OFDM (DCO-OFDM) for a m-MIMO VLC channel. Simulations performed over various m-MIMO VLC channels indicate that the derived analytical expressions for BER closely match with the simulated BER. Furthermore, MMSE-SIC is found to outperform ZF-SIC, which makes the proposed receiver viable for potential VLC deployments.