OFDM-Based Generalized Optical MIMO

The combination of multiple-input multiple-output (MIMO) transmission and orthogonal frequency division multiplexing (OFDM) modulation has been shown to be an effective way substantially enhance the capacity bandlimited optical wireless communication (OWC) systems. In this paper, we propose four OFDM-based generalized MIMO (GO-MIMO) techniques for intensity-modulation direct-detection OWC systems, including frequency-domain spatial (FD-GSM), (FD-GSMP), time-domain (TD-GSM) (TD-GSMP). For FD-GSM FD-GSMP, mapping is performed in domain, while it carried out time domain TD-GSM TD-GSMP. To efficiently estimate both constellation symbols each GO-MIMO technique, a corresponding maximum-likelihood (ML) detection algorithm designed. Extensive simulations are conducted evaluate compare performance under various settings typical indoor environment. Simulation results demonstrate that there exists optimal technique achieve target spectral efficiency given receiver location, obtained also related specific location receiver.