Experimental investigation of multi-band OCT precoding for OFDM-based visible light communications.

In this paper, we propose and experimentally demonstrate a channel-independent multi-band orthogonal circulant matrix transform (MB-OCT) precoding, to efficiently combat the severe frequency-selective fading of visible light communications (VLC). The proposed MB-OCT precoding exhibits an attractive ladder-like signal-to-noise-ratio (SNR) profile, thus can significantly reduce system BER by applying different quadrature amplitude modulation (QAM) level to different sub-bands. The impacts of sub-band number, signal bandwidth, and length of cyclic prefix (CP) on bit error rate (BER) of the VLC system are investigated. We experimentally compare BER performance of the proposed MB-OCT precoding with that of the conventional MB discrete Fourier transform (MB-DFT) precoding and the adaptive-loaded discrete multitone (DMT). The results show that the MB-OCT precoding outperforms the MB-DFT precoding and the single-band case for different data rates. Furthermore, it exhibits reduced implementation complexity and comparable BER performance with the adaptive-loaded DMT. For ~700-Mb/s VLC system with 2-m transmission distance, the BER is reduced from 1.53 × 10-2 to 1.17 × 10-4 by using the proposed MB-OCT precoding.

[1]  John M. Cioffi,et al.  A practical discrete multitone transceiver loading algorithm for data transmission over spectrally shaped channels , 1995, IEEE Trans. Commun..

[2]  Yang Hong,et al.  Experimental demonstration of an OCT-based precoding scheme for visible light communications , 2016, 2016 Optical Fiber Communications Conference and Exhibition (OFC).

[3]  Junyi Li,et al.  Visible light communication: opportunities, challenges and the path to market , 2013, IEEE Communications Magazine.

[4]  Yang Hong,et al.  Toward user mobility for OFDM-based visible light communications. , 2016, Optics letters.

[5]  Lin Chen,et al.  Experimental Demonstration of an IFFT/FFT Size Efficient DFT-Spread OFDM for Short Reach Optical Transmission Systems , 2016, Journal of Lightwave Technology.

[6]  Nan Chi,et al.  1.6 Gbit/s phosphorescent white LED based VLC transmission using a cascaded pre-equalization circuit and a differential outputs PIN receiver. , 2015, Optics express.

[7]  K. Habel,et al.  1.25 Gbit/s visible light WDM link based on DMT modulation of a single RGB LED luminary , 2012, 2012 38th European Conference and Exhibition on Optical Communications.

[8]  Chi-Wai Chow,et al.  Utilization of multi-band OFDM modulation to increase traffic rate of phosphor-LED wireless VLC. , 2015, Optics express.

[9]  Jian Zhao,et al.  Orthogonal Chirp Division Multiplexing , 2016, IEEE Transactions on Communications.

[10]  Parth H. Pathak,et al.  Visible Light Communication, Networking, and Sensing: A Survey, Potential and Challenges , 2015, IEEE Communications Surveys & Tutorials.

[11]  William Shieh,et al.  Coherent optical DFT-spread OFDM transmission using orthogonal band multiplexing. , 2012, Optics express.

[12]  C. H. Yeh,et al.  Equalization and pre-distorted schemes for increasing data rate in in-door visible light communication system , 2011, 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference.

[13]  Honglei Li,et al.  High Bandwidth Visible Light Communications Based on a Post-Equalization Circuit , 2014, IEEE Photonics Technology Letters.

[14]  Yang Hong,et al.  Experimental demonstration of performance-enhanced MIMO-OFDM visible light communications , 2017, 2017 Optical Fiber Communications Conference and Exhibition (OFC).