期刊名称：International Journal of Innovative Research in Computer and Communication Engineering
印刷版ISSN：2320-9798
电子版ISSN：2320-9801
出版年度：2015
卷号：3
期号：11
DOI：10.15680/IJIRCCE.2015.0311090
出版社：S&S Publications
摘要：The use of OFDM in optical wireless data transmission is due to its high data rate compared to othertransmission methods. Adaptive modulation is a technique used for maximizing the data throughput of subcarriersallocated to a user in OFDM system. A major limitation of existing visible light communication (VLC) systems is thelimited modulation bandwidth of light-emitting diodes used in the system. The Optical OFDM (O-OFDM) is sensitiveto the non-linear effects of LED. The proposed method is to use a delta-sigma modulator to convert a continuousmagnitude OFDM digital signal into a two level analog signal. This signal will be given as the input of a LED. By thisthe output of LED is equivalent to the output of on-off keying (OOK) signal and thus it is immune to the non-linearity.Simulation results validate that the proposed system improves the VLC system performance.
