ZTE

ZTE Communications ›› 2016, Vol. 14 ›› Issue (2): 29-40.DOI: 10.3969/j.issn.1673-5188.2016.02.004

• Special Topic • Previous Articles     Next Articles

Modulation Techniques for Li-Fi

Mohamed Sufyan Islim, Harald Haas   

  1. Li-Fi Research and Development Centre, Institute for Digital Communications, University of Edinburgh, Edinburgh EH9 3JL, UK
  • Received:2016-02-24 Online:2016-04-01 Published:2019-11-27
  • About author:Mohamed Sufyan Islim (m.islim@ed.ac.uk) received his BSc (1st Hons) in communications technology engineering in 2009, and MSc (Distinction) in communications engineering from Aleppo University, Syria in 2012. Among several scholarships he was awarded in 2013, he was awarded the Global Edinburgh Scholarship from Edinburgh University, UK. In 2014, he received another MSc (Distinction) in signal processing and communications from Edinburgh University. He was the recipient of the 2014 IEEE Communications Chapter Best Master Project Prize. Currently, he is a PhD student, under the supervision of Professor Harald Haas, at the Li-Fi Research and Development Centre, University of Edinburgh. His research interests include optical OFDM, Li-Fi, and optical wireless communications.
    Harald Haas (h.haas@ed.ac.uk) holds the chair for Mobile Communications at the School of Engineering, and is the director of the Li-Fi Research and Development Centre, University of Edinburgh, UK. Professor Haas has been working in wireless communications for 20 years and has held several posts in industry. He was an invited speaker at TED Global in 2011 where he demonstrated and coined“Li-Fi”. Li-Fi was listed among the 50 best inventions in TIME Magazine 2011. Moreover, his work has been covered in other international media such as the New York Times, BBC, MSNBC, CNN International, Wired UK, and many more. He is initiator, cofounder and chief scientific officer (CSO) of pureLiFi Ltd. Professor Haas holds 31 patents and has more than 30 pending patent applications. He has published 300 conference and journal papers including a paper in Science Magazine. He published two textbooks with Cambridge University Press. His h-index is 43 (Google). In 2015 he was co-recipient of three best paper awards including the IEEE Jack Neubauer Memorial Award. He is CI of programme grant TOUCAN (EP/L020009/1), and CI of SERAN (EP/L026147/1). He currently holds an EPSRC Established Career Fellowship (EP/K008757/1). In 2014, Professor Haas was selected as one of ten EPSRC UK RISE Leaders.
  • Supported by:
    This work is support by the UK Engineering and Physical Sciences Research Council (EPSRC) under Grants EP/K008757/1 and EP/M506515/1

Modulation Techniques for Li-Fi

Mohamed Sufyan Islim, Harald Haas   

  1. Li-Fi Research and Development Centre, Institute for Digital Communications, University of Edinburgh, Edinburgh EH9 3JL, UK
  • 作者简介:Mohamed Sufyan Islim (m.islim@ed.ac.uk) received his BSc (1st Hons) in communications technology engineering in 2009, and MSc (Distinction) in communications engineering from Aleppo University, Syria in 2012. Among several scholarships he was awarded in 2013, he was awarded the Global Edinburgh Scholarship from Edinburgh University, UK. In 2014, he received another MSc (Distinction) in signal processing and communications from Edinburgh University. He was the recipient of the 2014 IEEE Communications Chapter Best Master Project Prize. Currently, he is a PhD student, under the supervision of Professor Harald Haas, at the Li-Fi Research and Development Centre, University of Edinburgh. His research interests include optical OFDM, Li-Fi, and optical wireless communications.
    Harald Haas (h.haas@ed.ac.uk) holds the chair for Mobile Communications at the School of Engineering, and is the director of the Li-Fi Research and Development Centre, University of Edinburgh, UK. Professor Haas has been working in wireless communications for 20 years and has held several posts in industry. He was an invited speaker at TED Global in 2011 where he demonstrated and coined“Li-Fi”. Li-Fi was listed among the 50 best inventions in TIME Magazine 2011. Moreover, his work has been covered in other international media such as the New York Times, BBC, MSNBC, CNN International, Wired UK, and many more. He is initiator, cofounder and chief scientific officer (CSO) of pureLiFi Ltd. Professor Haas holds 31 patents and has more than 30 pending patent applications. He has published 300 conference and journal papers including a paper in Science Magazine. He published two textbooks with Cambridge University Press. His h-index is 43 (Google). In 2015 he was co-recipient of three best paper awards including the IEEE Jack Neubauer Memorial Award. He is CI of programme grant TOUCAN (EP/L020009/1), and CI of SERAN (EP/L026147/1). He currently holds an EPSRC Established Career Fellowship (EP/K008757/1). In 2014, Professor Haas was selected as one of ten EPSRC UK RISE Leaders.
  • 基金资助:
    This work is support by the UK Engineering and Physical Sciences Research Council (EPSRC) under Grants EP/K008757/1 and EP/M506515/1

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Abstract: Modulation techniques for light fidelity (Li-Fi) are reviewed in this paper. Li-Fi is the fully networked solution for multiple users that combines communication and illumination simultaneously. Light emitting diodes (LEDs) are used in Li-Fi as visible light transmitters, therefore, only intensity modulated direct detected modulation techniques can be achieved. Single carrier modulation techniques are straightforward to be used in Li-Fi, however, computationally complex equalization processes are required in frequency selective Li-Fi channels. On the other hand, multicarrier modulation techniques offer a viable solution for Li-Fi in terms of power, spectral and computational efficiency. In particular, orthogonal frequency division multiplexing (OFDM) based modula-tion techniques offer a practical solution for Li-Fi, especially when direct current (DC) wander, and adaptive bit and power loading techniques are considered. Li-Fi modulation techniques need to also satisfy illumination requirements. Flickering avoidance and dimming control are considered in the variant modulation techniques presented. This paper surveys the suitable modulation techniques for Li-Fi including those which explore time, frequency and colour domains.

Key words: light fidelity (Li-Fi), optical wireless communications (OWC), visible light communication (VLC), intensity modulation and direct detection (IM/DD), orthogonal frequency division multiplexing (OFDM)

摘要： Modulation techniques for light fidelity (Li-Fi) are reviewed in this paper. Li-Fi is the fully networked solution for multiple users that combines communication and illumination simultaneously. Light emitting diodes (LEDs) are used in Li-Fi as visible light transmitters, therefore, only intensity modulated direct detected modulation techniques can be achieved. Single carrier modulation techniques are straightforward to be used in Li-Fi, however, computationally complex equalization processes are required in frequency selective Li-Fi channels. On the other hand, multicarrier modulation techniques offer a viable solution for Li-Fi in terms of power, spectral and computational efficiency. In particular, orthogonal frequency division multiplexing (OFDM) based modula-tion techniques offer a practical solution for Li-Fi, especially when direct current (DC) wander, and adaptive bit and power loading techniques are considered. Li-Fi modulation techniques need to also satisfy illumination requirements. Flickering avoidance and dimming control are considered in the variant modulation techniques presented. This paper surveys the suitable modulation techniques for Li-Fi including those which explore time, frequency and colour domains.

关键词: light fidelity (Li-Fi), optical wireless communications (OWC), visible light communication (VLC), intensity modulation and direct detection (IM/DD), orthogonal frequency division multiplexing (OFDM)