PAPR Reduction and non linearity Alleviation Using Blend of Precoder and Compander in OFDM Based Visible Light Communication Systems

Abstract

With the advent of new technologies such as the internet of things (IoT), the use of internet protocol (IP) linked devices and machine-to-machine (M2M) communication are expected to outnumber the global population. The demand for high-capacity, fast indoor mobile data networks is expected to skyrocket in order to support applications demanding vast spectrum such as live streaming of high-definition (HD) videos, video conferences, e-tutoring, and so on. The current radio frequency (RF) technology standards (IEEE 802.11a/b/g/n) suffer from bandwidth congestion. In this regard, visible light communication (VLC) has attracted a lot of attention from academics and industry because of its twofold advantage of transmitting data and providing illumination simultaneously. Significant research works have been undertaken toward the expansion of VLC systems over the last decade due to its remarkable advantages over RF systems,such as cost-benefit, energy-efficient transmission, high security, and low latency. Since the modulation bandwidth of light emitting diodes (LEDs) used as transmitters is low,orthogonal frequency division multiplexing (OFDM) is most frequently employed in VLC systems to give wider cell coverage to a greater number of users. However, in VLC OFDM systems, the high peak-to-average power ratio (PAPR), which is an intrinsic property of OFDM signals, is a potential concern. The high PAPR distorts the signal and impairs the performance of OFDM based VLC systems due to the dynamic range constrained nonlinear behavior of LEDs.PAPR reduction is critical for reducing non-linearity in optical wireless communication(OWC) systems. Low PAPR signals have a lower dynamic range and are less responsive to nonlinearities than original input signals. However, in-band and out-of-band distortions, downward compatibility, and computational complexity are a few important factors to consider while deciding the best PAPR reduction strategy.