Advanced modulation techniques for visible light communications: Review and Evaluation by MATLAB
Abstract:Visible light communications (VLC) utilizes the LED-based lighting fixtures in indoor environments for illumination, data communication, sensing, and indoor positioning. One main goal is to enhance transmission data rates of IM/DD VLC systems, which is mainly limited by the modulation bandwidth of the LED. To resolve this problem, techniques such as equalization, multi-level modulation and multicarrier modulation (MCM) may be used. One attractive MCM scheme is the orthogonal frequency division multiplexing (OFDM). To ensure real-valuedness of the optical signals, Hermitian symmetry is used, while for the unipolarity some variants such as DCO-OFDM, ACO-OFDM, PAM-DMT, and U-OFDM are used. Recently, in place of Discrete Fourier Transform (DFT) in OFDM, other alternatives have been suggested including Discrete Wavelet Transform (DWT), Fractional Fourier Transform (FRFT), Generalized Frequency Division Multiplexing using Discrete Prolate Spheroidal Sequences (DPSS), etc. In this talk, such advanced modulation schemes in VLC systems are reviewed and numerically compared using MATLAB.
Biography: Dr Gholamreza Baghersalimi received his B.Sc. degree from the University of Tehran, Iran, M.Sc. degree from Tarbiat Modares University, Iran, and Ph.D. degree from the University of Leeds, UK, all in Electrical Engineering. Now, he is an Associate Professor in the Department of Electrical Engineering, the University of Guilan (UG), Rasht, Iran. Before joining the UG, he worked for Iran Telecommunications Research Center (ITRC) and Data Communications of Iran (DCI). His research interests are focused on physical layer signal processing techniques in fiber-optic communication systems, optical wireless communications especially visible light communications. He has published over 50 journal and conference papers and graduated over 50 M.Sc. students. He also coauthored a book on underwater acoustic communications.