LACO-OFDM With Index Modulation for Optical Wireless Systems

• Published in: IEEE wireless communications letters Vol. 10; no. 3; pp. 664 - 667
• Main Authors: Azim, Ali Waqar, Le Guennec, Yannis, Chafii, Marwa, Ros, Laurent
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01-03-2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); IEEE comsoc
• Subjects: Alternative energy sources; Bandwidths; Computer Science; Discrete Fourier transform; Distortion; Harmonic analysis; Harmonics; index modulation; Indexes; Integrated optics; intensity-modulation and direct-detection; Modulation; OFDM; Optical modulation; Optical wireless; optical wireless systems; Optimization; Orthogonal Frequency Division Multiplexing; Signal and Image Processing; Spectra; Wireless communication; Integrated optics; Wireless communication; OFDM; Harmonic analysis; Distortion; Indexes; Optical modulation
• ISSN: 2162-2337; 2162-2345
• DOI: 10.1109/LWC.2020.3045119

In this letter, we propose layered asymmetrically clipped optical-orthogonal frequency-division multiplexing (LACO-OFDM) with index modulation (IM), i.e., LACO-OFDM-IM for optical wireless systems. In classical LACO-OFDM, the spectral leakage because of out-of-band clipping harmonics increases the baseband bandwidth (BB) resulting in lower spectral efficiencies. For LACO-OFDM-IM, we use IM and optimize the BB by filtering the out-of-band clipping harmonics. This amalgamation of IM and BB optimization leads to better spectral efficiency (SE). Simulation results shall affirm that LACO-OFDM-IM achieves higher SE, affords a comprehensive granularity for SE/energy efficiency trade-off, and outperforms classical alternatives in terms of bit-error-rate in both line-of-sight and time-dispersive channels.