TY - JOUR
T1 - Optical MIMO-OFDM with Generalized LED Index Modulation
AU - Yesilkaya, Anil
AU - Basar, Ertugrul
AU - Miramirkhani, Farshad
AU - Panayirci, Erdal
AU - Uysal, Murat
AU - Haas, Harald
N1 - Funding Information:
Manuscript received October 31, 2016; revised March 14, 2017; accepted April 19, 2017. Date of publication May 2, 2017; date of current version August 14, 2017. This work was supported by the European Cooperation in Science and Technology (COST) - The Scientific and Technological Research Council of Turkey (TUBITAK) Research Grant No. 113E307. This work was partially supported by EPSRC under Established Career Fellowship Grant EP/K008757/1. This paper was presented at the 2016 IEEE International Conference on Communications, Kuala Lumpur, Malaysia. The associate editor coordinating the review of this paper and approving it for publication was G.-C. Yang. (Corresponding author: Anil Yesilkaya.) A. Yesilkaya was with the Department of Electrical and Electronics Engineering, Kadir Has University, 34083 Istanbul, Turkey. He is with the LiFi Research and Development Centre, Institute for Digital Communications, The University of Edinburgh, Edinburgh EH9 3JL, U.K. (e-mail: a.yesilkaya@ed.ac.uk).
Publisher Copyright:
© 1972-2012 IEEE.
PY - 2017/8
Y1 - 2017/8
N2 - Visible light communications (VLC) is a promising and uncharted new technology for the next generation of wireless communication systems. This paper proposes a novel generalized light emitting diode (LED) index modulation method for multiple-input-multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM)-based VLC systems. The proposed scheme avoids the typical spectrum efficiency losses incurred by time- and frequency-domain shaping in OFDM signals. This is achieved by exploiting spatial multiplexing along with LED index modulation. Accordingly, real and imaginary components of the complex time-domain OFDM signals are separated first, then resulting bipolar signals are transmitted over a VLC channel by encoding sign information in LED indexes. As a benchmark, we demonstrate the performance analysis of our proposed system for both analytical and physical channel models. Furthermore, two novel receiver designs are proposed. Each one is suitable for frequency-flat or selective channel scenarios. It has been shown via extensive computer simulations that the proposed scheme achieves considerably better bit error ratio versus signal-to-noise-ratio performance than the existing VLC-MIMO-OFDM systems that use the same number of transmit and receive units [LEDs and photo diodes (PDs)]. Compared with the single-input single-output (SISO) DC biased optical (DCO)-OFDM system, both spectral efficiency and DC bias can be doubled and removed respectively simply by exploiting a MIMO configuration.
AB - Visible light communications (VLC) is a promising and uncharted new technology for the next generation of wireless communication systems. This paper proposes a novel generalized light emitting diode (LED) index modulation method for multiple-input-multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM)-based VLC systems. The proposed scheme avoids the typical spectrum efficiency losses incurred by time- and frequency-domain shaping in OFDM signals. This is achieved by exploiting spatial multiplexing along with LED index modulation. Accordingly, real and imaginary components of the complex time-domain OFDM signals are separated first, then resulting bipolar signals are transmitted over a VLC channel by encoding sign information in LED indexes. As a benchmark, we demonstrate the performance analysis of our proposed system for both analytical and physical channel models. Furthermore, two novel receiver designs are proposed. Each one is suitable for frequency-flat or selective channel scenarios. It has been shown via extensive computer simulations that the proposed scheme achieves considerably better bit error ratio versus signal-to-noise-ratio performance than the existing VLC-MIMO-OFDM systems that use the same number of transmit and receive units [LEDs and photo diodes (PDs)]. Compared with the single-input single-output (SISO) DC biased optical (DCO)-OFDM system, both spectral efficiency and DC bias can be doubled and removed respectively simply by exploiting a MIMO configuration.
KW - LED index modulation
KW - Visible light communications (VLC)
KW - maximum-a-posteriori probability (MAP) estimator
KW - multiple-input-multiple-output (MIMO) systems
KW - optical-spatial modulation (OSM)
KW - orthogonal frequency division multiplexing (OFDM)
UR - http://www.scopus.com/inward/record.url?scp=85029509430&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85029509430&partnerID=8YFLogxK
U2 - 10.1109/TCOMM.2017.2699964
DO - 10.1109/TCOMM.2017.2699964
M3 - Article
AN - SCOPUS:85029509430
SN - 0090-6778
VL - 65
SP - 3429
EP - 3441
JO - IEEE Transactions on Communications
JF - IEEE Transactions on Communications
IS - 8
M1 - 7915761
ER -