Superimposed training-based channel estimation for miso optical-OFDM vlc Articles uri icon

publication date

  • June 2019

start page

  • 6161

end page

  • 6166

issue

  • 6

volume

  • 68

International Standard Serial Number (ISSN)

  • 0018-9545

Electronic International Standard Serial Number (EISSN)

  • 1939-9359

abstract

  • In this paper, we investigate a novel channel estimation (CE)method for multiple-input and single-output (MISO) systems in visible lightcommunication (VLC). Direct current biased optical orthogonal frequencydivision multiplexing (DCO-OFDM) is commonly used in VLC where halfof the available subcarriers are spent to guarantee a real-valued outputafter the inverse fast Fourier transform operation. Besides, dedicated subcarriers are typically used for CE, thus, many resources are wasted andthe spectral efficiency is degraded. We propose a superimposed trainingapproach for CE in MISO DCO-OFDM VLC scenarios. Analytical expressions of mean squared error (MSE) and spectral efficiency are derived whenthe least squares estimator is considered. This analysis is valid for outdoorand indoor scenarios. For the CE error, simulation results of MSE showa perfect match with analytical expressions. Moreover, results prove thatthis technique guarantees a larger spectral efficiency than previous schemeswhere dedicated pilots were used. Finally, the optimal data power allocationfactor is also analytically derived.

keywords

  • channel estimation; dco-ofdm; superimposed training; visible light communication