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In this paper, a hybrid scheme for optical wireless communications using LED lamps is proposed. This scheme allows both visible light communication (VLC) using photodetectors and optical camera communication (OCC) using image sensors of a camera to receive light signals from the same transmitter simultaneously. High-frequency signals are received by VLC, while low-frequency signals are received by OCC. This hybrid transmission system enables the provision of versatile indoor services and allows users to receive data regardless of their device. It reduces the deployment cost of an indoor optical wireless system since the proposed system can provide both services using one LED lamp. To use the dimming property of LED lamps, a variable pulse position modulation scheme is used for OCC, while Manchester coding is used in VLC to avoid flickering. The measurement shows that the transmission distance reaches more than 4 m for both services. Performance analysis and experimental results are presented. INDEX TERMS Visible light communications, optical camera communications, variable pulse position modulation, VLC/OCC hybrid.

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