A Robust CDMA VLC System Against Front-End Nonlinearity

The nonlinearity of a light-emitting diode (LED) limits the system performance of a visible light communications (VLC) system. Many nonlinearity mitigation methods have been studied. Recent technology advances in the micro-LED array have provided a simple alternative to deal with the system nonlinearity. In this paper, we study the approach of providing multiple access for the VLC system with the micro-LED array. A code-division multiple-access (CDMA) scheme that enables multiple access with variable data rate is proposed. In addition, the proposed system architecture is immune to the nonlinearity of the micro-LED array, thus providing optimal system performance. Simulations and laboratory experiments show the robustness and consistency of the proposed scheme.

[1]  Chi-Wai Chow,et al.  Color-Shift Keying and Code-Division Multiple-Access Transmission for RGB-LED Visible Light Communications Using Mobile Phone Camera , 2014, IEEE Photonics Journal.

[2]  Yang Yang,et al.  On the benefit of DMT modulation in nonlinear VLC systems. , 2015, Optics express.

[3]  High-bandwidth parallel data transmission using GaN/CMOS micro-LED arrays , 2012, IEEE Photonics Conference 2012.

[4]  H. Qian,et al.  Adaptive Postdistortion for Nonlinear LEDs in Visible Light Communications , 2014, IEEE Photonics Journal.

[5]  M. Dawson,et al.  High-Speed Visible Light Communications Using Individual Pixels in a Micro Light-Emitting Diode Array , 2010, IEEE Photonics Technology Letters.

[6]  Raviv Raich,et al.  Optimization of SNDR for amplitude-limited nonlinearities , 2005, IEEE Transactions on Communications.

[7]  Shiho Sasaki,et al.  A visible-light communication system using optical CDMA with inverted MPSC , 2013, The Sixth International Workshop on Signal Design and Its Applications in Communications.

[8]  M. Dawson,et al.  Visible-Light Communications Using a CMOS-Controlled Micro-Light- Emitting-Diode Array , 2012, Journal of Lightwave Technology.

[9]  Nan Chi,et al.  Enhanced performance of visible light communication employing 512-QAM N-SC-FDE and DD-LMS. , 2014, Optics express.

[10]  Harald Haas,et al.  Indoor optical wireless communication: potential and state-of-the-art , 2011, IEEE Communications Magazine.

[11]  Robert J. Baxley,et al.  Nonlinear distortion mitigation in visible light communications , 2015, IEEE Wireless Communications.

[12]  Wei Xu,et al.  One-Bit Sigma-Delta Modulator for Nonlinear Visible Light Communication Systems , 2015, IEEE Photonics Technology Letters.

[13]  H. Qian,et al.  Digitally Controlled Micro-LED Array for Linear Visible Light Communication Systems , 2015, IEEE Photonics Journal.

[14]  Harald Haas,et al.  Non-linearity effects and predistortion in optical OFDM wireless transmission using LEDs , 2009, Int. J. Ultra Wideband Commun. Syst..

[15]  Mohammad Noshad,et al.  High-speed visible light indoor networks based on optical orthogonal codes and combinatorial designs , 2013, 2013 IEEE Global Communications Conference (GLOBECOM).