Fractionally spaced equalization in visible light communication

Visible light communication (VLC) utilizing white light emitting diode (LED) is considered as a strong candidate for the future lighting technology. The LEDs are distributed across the ceiling and have wide irradiance distribution for achieving adequate general lighting. But the bandwidth-limited LED channel and indoor multipath propagation delays cause severe inter-symbol interference (ISI). Bit error rate (BER) performance of the indoor visible light wireless system is degraded significantly when increasing the data rate. In this paper, we discuss about the equalization system using fractionally-spaced equalization (FSE) and evaluate its performance in a VLC system. As a result, the performance of FSE is superior to the equalizer with symbol interval sampling. Further more, this equalization method is suitable for a bandwidth-limited optical multipath channel.