ESIM-OFDM-based transceiver design of a visible light communication system M. Ahsan 1 and H. M. Asif 2, * ,† 1 School of Engineering and Computing Sciences, New York Institute of Technology, New York, USA 2 Department of Electrical Engineering, COMSATS Institute of Information Technology, Lahore, Pakistan SUMMARY Visible light communication (VLC) system has been becoming a potential technology for short-range data communication over wireless optical channel. In this paper, a real-time state-of-the-art VLC system proto- type is implemented mainly based on enhanced subcarrier index modulation orthogonal frequency division multiplexing (ESIM-OFDM) modulation scheme. The prototype has been designed using NI cDAQ hard- ware equipment programmed in MATLAB/LABVIEW. In other words, the developed VLC transceiver LABVIEW model is loaded into cDAQ to perform real-time transmission of text data. The design mainly comprises VLC transmitter, VLC receiver, interfacing NI cDAQ with LABVIEW, and implementation of ESIM-OFDM. It should be noted that the direct output of ESIM-OFDM is not suitable to drive VLC trans- mitter circuit; therefore, the key contribution lies in making use of sigma–delta modulator to modify ESIM- OFDM output to produce constant current signal which in turn could drive VLC transmitter. The second main contribution of the work targets the luminous properties of the designed transmitter that have experi- mentally been characterized using a LUX meter. Finally, the last contribution of the work is the simulation carried out to analyze the performance of the proposed system with other existing VLC modulation schemes. Copyright © 2016 John Wiley & Sons, Ltd. Received 29 September 2015; Revised 16 March 2016; Accepted 12 July 2016 KEY WORDS: transceiver; visible light communication; LABVIEW; LUX meter; implementation 1. INTRODUCTION In the recent years, the newly emerging wireless communication technology, visible light commu- nication (VLC), is being rapidly commercialized all over the world as a means of innovative and green data communication [1]. It can be used to shift the high data demand from the saturated radio wave spectrum to the available band of visible light in the electromagnetic spectrum, thereby giving interference free communication [2]. The VLC transmitter, that is, light-emitting diode (LED), emits incoherent light due to which di- rect phase/amplitude modulation cannot be applied because it would not be detected by the photo detector. In other words, only intensity modulation and direct detection (IM/DD) can be used in VLC systems. Different modulation schemes have been used for VLC system so that the light may be used for data communication [3, 4]. However, inter-symbol interference (ISI) becomes a crucial issue at high modulation speed in these modulation schemes. Therefore, a suitable form of orthogonal frequency division multiplexing (OFDM) becomes the obvious choice for VLC be- cause it is inherently resilient to both ISI and inter-carrier interference (ICI) [5, 6]. Many variants of OFDM have been used for VLC system. Subcarrier index modulation (SIM) *Correspondence to: Hafiz M. Asif, Department of Electrical Engineering, COMSATS Institute of Information Technol- ogy, Lahore, Pakistan. † E-mail hafizasif@ciitlahore.edu.pk Copyright © 2016 John Wiley & Sons, Ltd. INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS Int. J. Commun. Syst. (2016) Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/dac.3175