High-Dimensional Radial Basis Function Extension Interpolation Nonlinear Post-Distorter in Visible Light Communication Systems

Abstract

The nonlinearity induced by light-emitting diode (LED) affects the normal transmission and reception, which significantly limits the performance of visible light communication (VLC) system. To address the problem induced by the nonlinearity of LED, a post-distorter for orthogonal frequency division multiplexing (OFDM) based VLC is proposed in this paper. Radial basis function (RBF) interpolation, known as an excellent function approximation method, is investigated to implement the nonlinearity mitigations. To further remove the memory effect of LED, which could not be ignored, we propose to extend RBF to a high-dimensional interpolation so that it can eliminate both nonlinearity and memory effect simultaneously. The performance of the proposed RBF extension interpolation is verified by numerical simulations, and a better performance in suppressing nonlinearity is obtained in VLC-OFDM systems as compared with the frequency domain nonlinear compensation method. A signal-to-noise ratio gain of 2dB in terms of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{{E}_b} \mathord{/ {\vphantom {{{E}_b} {{N}_0}}} } {{N}_0}}$</tex-math></inline-formula> can be obtained when bit error rate is about 6*10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−7</sup> at 6dB power back-off (PBO), while 6dB gain can be achieved when BER is 2*10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> at 4dB PBO.