PAPR Reduction of Wavelet-OFDM Signals Using Exponential Companding in Visible Light Communications

Abstract

Visible light communication (VLC) is considered one of the newest wireless communication technologies that provides transmitted signals with high data rate. Orthogonal frequency division multiplexing (OFDM) is used extensively in VLC due to its ability to support high speed transmission and it gets ride of the inter-symbol interference [1]. OFDM enhancement with wavelet based on discrete wavelet transform (DWT) has achieved remarkable performance compared to OFDM due to interesting wavelet characteristics. OFDM suffers from the issue of peak to average power ratio (PAPR) which reduces the system efficiency especially in VLC system due to the nonlinearity of light emitting diode (LED) which distorts the signal. Wavelet proved an improvement in PAPR reduction of the radiated signal. In our study, an exponential companding PAPR reduction technique is applied on a wavelet-OFDM which satisfies better enhancement in PAPR reduction of the transmitted signal.