Comparative study of various modulation schemes used in indoor VLC

Abstract

This thesis work proposes analysis and simulation of 5G multi-carrier transmission schemes based on generalized frequency division multiplexing (GFDM) along with existing optical orthogonal frequency division multiplexing (O-OFDM) for indoor visible light communication (VLC).The aim is to overcome the inherent drawbacks of the commonly used optical orthogonal frequency division multiplexing (O-OFDM) schemes. Various performance metrics are analyzed and compared with O-OFDM schemes. It is found that proposed scheme has better spectral and power efficiency. Also its symbol error rate (SER) performance is found to be superior over optical OFDM counterparts under line-of-sight (LOS) optical channel. Simulation results based on SER, peak-to-average-power-ratio (PAPR), and numerical analysis on spectral efficiency validate the performance of the proposed schemes. As GFDM is being actively considered for LTE-A like 5G systems, it is expected that the O-GFDM based VLC system will very well gel with next generation wireless systems to offer seamless end-to-end communication services and will provide greater exibility using software defined networking. Thesis work also includes a DFT-precoded optical OFDM modulation scheme to overcome the inherent drawback of high PAPR of DCO-OFDM and this scheme is compared with DCO-OFDM in context of SER and PAPR performances. Its better SER performance and reduced PAPR make it suitable as the substitute of DCO-OFDM.