SCFDE with space-time coding for IM/DD optical wireless communication

Recently, we proposed a novel transmission scheme termed decomposed-quadrature optical single carrier frequency domain equalization (DQO-SCFDE) suitable for intensity-modulated direct-detection (IM/DD) diffuse optical wireless (DOW) communication. DQO-SCFDE has been shown to perform better than the conventional asymmetrically clipped optical OFDM (ACO-OFDM) when the non-linearity characteristics of the light emitting diodes (LED) are considered. In this paper we present a detail comparison of DQO-SCFDE and ACO-OFDM. We then propose a space-time coding scheme for DQO-SCFDE using two LED's at the transmitter to improve the bit-error rate performance.