Performance analysis of partial pre-equalization for ACO-OFDM indoor optical wireless transmissions

We propose partial pre-equalization for indoor optical wireless transmissions based on asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) with intensity modulation and direct detection (IM/DD). Bit loading is applied to minimize the transmit optical power for a fixed target BER. Similar to pre-equalization, for diffuse indoor optical wireless channels, partial pre-equalization can reduce the transmit optical power over post-equalization for point-to-point transmissions. In addition, we consider broadcast transmissions to multiple users with possibly different channel qualities, where pre-equalization is not applicable. Finally, we specify an appropriate channel estimate at the transmitter for such broadcast transmissions.