Performance analysis of adaptive channel estimation for U-OFDM indoor visible light communication

The paper presents a performance analysis for optical in-door communication system based on orthogonal frequency division multiplexing (OFDM) modulation with adaptive channel estimation. Modulation parameters will be adapted to meet the optical domain circumstances mainly the non-availability of bipolar signals. Three schemes to come over the bipolarity issues are available. Asymmetrical clipped optical OFDM (ACO-OFDM), DC Biased optical-OFDM DCO-OFDM and unipolar OFDM (U-OFDM). Paper considers the use U-OFDM because it provides a best performance. The adaptive channel estimation is applied, since the moving receiver doesn't know the channel. LS (least square) and block-type pilot are used in the proposed simulation. And finally to show the effect of changing the receiver position on the BER performance for different constellation order.