Offset modulation for visible light communication systems

In this paper we discuss a new transmission approach for orthogonal frequency division multiplexing (OFDM) in visible light communication (VLC) systems. Unlike existing approaches of OFDM-based VLC systems, the real signal is obtained by utilizing offset modulation (OM) in OFDM-based VLC that can efficiently utilize the available bandwidth without the need of Hermitian symmetry. In the proposed OM-OFDM based VLC scheme, the complex OFDM signals are phased mapped into real values and hence a good bit error rate (BER) performance is achieved compared to conventional approaches. Since no Hermitian symmetry is required in the proposed scheme, simulation results demonstrate that our approach yields 50% improvement in spectral efficiency compared to existing approaches with the same modulation order. Furthermore, the proposed scheme also achieves a considerable reduction in peak-to-average power ratio (PAPR), which is the major drawback of optical OFDM systems. ©2019 by Begell House, Inc.