Asymmetrical Hybrid Optical OFDM for Visible Light Communications With Dimming Control

Wang, Chunya; Hanzo, Lajos; Dai, Linglong

doi:10.1109/lpt.2015.2404972

Cited by 109 publications

(71 citation statements)

References 18 publications

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“…In addition, the modulation scheme should support extreme illumination requirements such as very low or very high intensities. Several schemes have been proposed for conventional optical OFDM to support dimming control in VLC [36,37], which can be extended to the IM-OFDM schemes. Furthermore, given the property of IM-OFDM, we can use different number of activated subcarriers for various illumination requirements.…”

Section: Dimming Compatibilitymentioning

confidence: 99%

Index Modulation-Aided OFDM for Visible Light Communications

Wang¹,

Mao²,

Hanzo³

2017

Visible Light Communications

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Index modulation-aided orthogonal frequency-division multiplexing(IM-OFDM) is a promising modulation technique to achieve high spectral and energy efficiency. In this chapter, the conventional optical OFDM schemes are firstly reviewed, followed by the principles of IM-OFDM. The application of IM-OFDM in visible light communication (VLC) systems is introduced, and its performance is compared with conventional optical OFDM, which verifies its superiority. Finally, the challenges and opportunities of IM-OFDM are discussed for the VLC applications.

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Section: Dimming Compatibilitymentioning

confidence: 99%

Index Modulation-Aided OFDM for Visible Light Communications

Wang¹,

Mao²,

Hanzo³

2017

Visible Light Communications

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“…It has been proved that the asymmetric clipping distortion of PAM-DMT signal only falls on the real part of even subcarriers, which has no effect on the data in ACO-OFDM [9]. Hence, the receiver can regenerate the ACO-OFDM and PAM-DMT signals to recover the phase factors and data sequentially [10].…”

Section: Dear Editormentioning

confidence: 99%

Modified PTS-based PAPR reduction for ACO-OFDM in visible light communications

Tan

Wang

2015

Sci. China Inf. Sci.

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CitationTan J D, Wang Q, Wang Z C. Modified PTS-based PAPR reduction for ACO-OFDM in visible light communications. Sci China Inf Sci, 2015, : xxxxxx(3), doi: xxxxxxxxxxxxxx Dear editor,Visible light communication (VLC) has raised great interests since it supplements the unlicensed spectrum resource for ultra-high data rate transmission [1]. In order to resist time dispersion and guarantee the real-valued and non-negative constraint in VLC channel, DC-biased optical orthogonal frequency-division multiplexing (DCO-OFDM) and asymmetrically clipped optical OFDM (ACO-OFDM) techniques have been utilized in VLC systems [2]. Unlike DCO-OFDM which requires high DC bias [3], ACO-OFDM enjoys an advantage of high power efficiency and wide light emitting diodes (LED) dynamic region.The inherent peak-to-average power ratio (PAPR) issue of VLC OFDM leads to severe LED nonlinear distortion, which deteriorates the bit error rate (BER) performance [1]. Several methods reported in [4][5][6][7] have been investigated to reduce PAPR and mitigate LED nonlinear distortion of OFDM-based VLC systems. However, the costs such as data rate and performance loss induced by the above algorithms could not be neglected.As an effective method for PAPR reduction, partial transmit sequence (PTS) technique has an advantage of negligible performance degradation and no power increase. However, side information is required at the receiver, which results in data throughput loss [8]. In this letter, we propose a modified PTS-based PAPR reduction scheme for ACO-OFDM in VLC systems by exploiting the unoccupied subcarriers to transmit side information. A novel transmitter is presented to apply the PTS technique in ACO-OFDM VLC system without data throughput loss and an original power allocation method is also proposed to mitigate the power efficiency loss induced by the side information signals. Simulation results demonstrate that the proposed scheme achieves a significant PAPR reduction performance without data throughput loss as well as an improved BER performance when LED nonlinearity exists.Methodology. At the transmitter, the quadrature amplitude modulation (QAM) symbols X ACO of N -point ACO-OFDM block is divided into V disjoint clusters { X

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“…The operation efficiency of a channel estimator is dependent on the channel impulse response estimation in MIMO system. In [7] a channel impulse response estimation based on the correlation of transmits or receive antennas. An approach of concatenated wiener filters for the optimization of channel estimation by optimizing the channel characteristic in time and frequency domain.…”

Section: Introductionmentioning

confidence: 99%