Bidirectional 16-QAM OFDM in-building network over SMF and free-space VLC transport.

A bidirectional 16-quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM) in-building network over 20 km single-mode fiber (SMF) and 15 m free-space visible light communication (VLC) transport is proposed and experimentally demonstrated. Good bit error rate performances and clear constellation maps are obtained for 16-QAM OFDM applications in our proposed in-building networks.