Two input one output visible light communication system based on pulse amplitude modulation

Shi Meng; Zhang Mengjie; Chi Nan

doi:10.12086/oee.2019.180306

Article navigation > Opto-Electronic Engineering > 2019 Vol. 46 > No. 5 > 180306

Next Article Previous Article

Shi Meng, Zhang Mengjie, Chi Nan. Two input one output visible light communication system based on pulse amplitude modulation[J]. Opto-Electronic Engineering, 2019, 46(5): 180306. doi: 10.12086/oee.2019.180306

Citation:

Shi Meng, Zhang Mengjie, Chi Nan. Two input one output visible light communication system based on pulse amplitude modulation[J]. Opto-Electronic Engineering, 2019, 46(5): 180306. doi: 10.12086/oee.2019.180306

Two input one output visible light communication system based on pulse amplitude modulation

Key Laboratory of Electromagnetic Wave Information Science, Ministry of Education, Department of Communication Science and Engineering, Fudan University, Shanghai 200433, China

Fund Project: Supported by National Natural Science Foundation of China Project (61571133) and National Key Research and Development Program of China (2017YFB0403603)

More Information

Corresponding author: Chi Nan, E-mail:nanchi@fudan.edu.cn

Received Date 05 June 2018

Revised Date 03 November 2018

Published Date 01 May 2019

Abstract

Abstract

To improve the data transmission rate of the conventional point-to-point single input single output (SISO) visible light communication system, a multiple input multiple output (MIMO) visible light communication system is proposed. Considering the complexity of the receiver system, multiple input single output (MISO) visible light communication systems have attracted attention. This paper studies the MISO visible light communication system based on pulse amplitude modulation (PAM), and experimentally proves the advantages of this system in specific scenes. In addition, there are non-linear effects for key devices such as LED light sources and power amplifiers in visible light communication systems. Based on 2×1 MISO visible light communication system, this paper reports a novel equal probability coding mapping scheme for high-order PAM signals with two low-order PAM signals superposition in the optical domain. The system verification is performed through a net data-rate of 700 Mb/s transmission experiment through a red chip of RGB-LED, which proves the feasibility and superiority of this scheme in practice.
- optical communications /
- visible light communication /
- multiple input single output (MISO) /
- equal probability coding /
- pulse amplitude modulation (PAM)

FullText(HTML)

References

[1]	Zeng L B, O'Brien D C, Le Minh H, et al. High data rate multiple input multiple output (MIMO) optical wireless communications using white LED lighting[J]. IEEE Journal on Selected Areas in Communications, 2009, 27(9): 1654–1662. doi: 10.1109/JSAC.2009.091215 CrossRef Google Scholar
[2]	Mesleh R, Mehmood R, Elgala H, et al. Indoor MIMO optical wireless communication using spatial modulation[C]//Proceedings of 2010 IEEE International Conference on Communications, 2010: 1–5. Google Scholar
[3]	Yu Z H, Baxley R J, Zhou G T. Multi-user MISO broadcasting for indoor visible light communication[C]//Proceedings of 2013 IEEE International Conference on Acoustics, Speech and Signal Processing, 2013: 4849–4853. Google Scholar
[4]	Qian H, Yao S J, Cai S Z, et al. Adaptive postdistortion for nonlinear LEDs in visible light communications[J]. IEEE Photonics Journal, 2014, 6(4): 7901508. doi: 10.1109/JPHOT.2014.2331242 CrossRef Google Scholar
[5]	王灿, 周盈君, 迟楠.可见光通信中抗非线性方法的比较研究[J].中国照明电器, 2017(7): 9–15, 26. doi: 10.3969/j.issn.1002-6150.2017.07.002 CrossRef Google Scholar Wang C, Zhou Y J, Chi N. Research of LED's nonlinear distortion compensation algorithm in visible light communications[J]. China Light & Lighting, 2017(7): 9–15, 26. doi: 10.3969/j.issn.1002-6150.2017.07.002 CrossRef Google Scholar
[6]	Zhang M J, Shi M, Wang F M, et al. 4.05-Gb/s RGB LED-based VLC system utilizing PS-Manchester coded Nyquist PAM-8 modulation and hybrid time-frequency domain equalization[C]//Proceedings of the Optical Fiber Communication Conference, 2017: 1–3. Google Scholar

Overview

Overview

Overview: To improve the data transmission rate of the conventional point-to-point single input single output (SISO) visible light communication system, a multiple input multiple output (MIMO) visible light communication system is proposed. Considering the complexity of the receiver system, multiple input single output (MISO) visible light communication systems have attracted attention.
In addition, in the VLC system, a series of key devices such as LED light sources and power amplifiers have nonlinear effects, and the nonlinear distortion of the system would damage the system performance. The nonlinearity of the LED modulation curve is the main source of nonlinearity in the VLC system. The visible light signal is mainly modulated in the linear region of the LED to reduce the signal damage caused by nonlinear distortion. However, at this time, the luminous efficiency of the LED is low, and the illumination brightness generally cannot meet the lighting requirements of the actual application scene. What’s more, for high-order modulation signals, the peak-to-average power ratio (PAPR) of the signal is higher due to an increase in the number of signal levels, and is more susceptible to system nonlinearity. Therefore, in the MISO system, multiple LED lights can be used to transmit signals at the same time, low-order signals are modulated on each lamp, and high-order signals are generated by superposition of optical signals to resist nonlinear distortion of the LED at the transmitter. The simultaneous light emission of multiple LED lights can also increase the brightness of the lighting to meet the actual lighting requirements.
This paper studies the MISO visible light communication system based on pulse amplitude modulation (PAM), and proves the advantages of using this system in specific scenes by experiment. Based on 2×1 MISO visible light communication system, a novel equal probability coding mapping scheme for high-order PAM signals with two low-order PAM signals superposition in the optical domain is designed. In the experiment, we investigated and compared the BER performance under different bias tee voltage and V_pp for four systems which are single-input-single-output generation PAM7 signals with equal probability and unequal probability, two-input-one-output generation PAM7 signals with equal probability and unequal probability, respectively. The experimental results show that the scheme we proposed, for generating equal-probability PAM7 signals in 2×1 MISO system with the large average Euclidean distance between symbols and a lower PAPR, can effectively resist the inter-symbol interference and the nonlinear distortion of LEDs and enlarge the dynamic working area of the system. Finally, the system verification is performed through a net data-rate of 700 Mb/s transmission experiment utilizing a red chip of RGB-LED, which proves the feasibility and superiority of this scheme in practice.