Abstract
Visible light communications (VLC) employ visible light for communication within the frequency spectrum from 430 THz to 790 THz. The ultra-wide bandwidth resolves the spectrum exhaustion in radio frequency communications. Light-fidelity (LiFi) takes VLC further to achieve high speed, bi-directional and fully networked wireless communications. Light-emitting diode (LED) is the major light source employed by LiFi as LED is energy efficient for illumination, and at the same time can achieve high speed data transmission thanks to the LED fast switching capability. Now, LED communications, one of the major application scenarios of LiFi, have attracted huge attention and research interests. A variety of advantages are offered including the unregulated wide bandwidth, energy efficiency, safety, etc., which makes LED communications a promising supplement to the fifth generation (5G) communications. LED is the major source of nonlinearity in LED communications and LED also exhibits significant memory effect in the case of high data rate, which degrade the system performance severely. Hence, the nonlinear distortion and memory effect need to be handled properly. Polynomial based methods have been proposed to address the issue in the literature. However, the conventional polynomial based techniques suffer from numerical instability easily in determining the coefficients of the polynomials, resulting in significantly compromised performance.