  Visible Light Communication (VLC) technology using light emitting diodes
(LEDs) has been gaining increasing attention in recent years as it is appealing
for a wide range of applications such as indoor positioning. Orthogonal
frequency division multiplexing (OFDM) has been applied to indoor wireless
optical communications in order to mitigate the effect of multipath distortion
of the optical channel as well as increasing data rate. In this paper, we
investigate the indoor positioning accuracy of optical based OFDM techniques
used in VLC systems. A positioning algorithm based on power attenuation is used
to estimate the receiver coordinates. We further calculate the positioning
errors in all the locations of a room and compare them with those of single
carrier modulation scheme, i.e., on-off keying (OOK) modulation. We demonstrate
that OFDM positioning system outperforms its conventional counterpart.
