Multi-layer Modulation for Intensity-Modulated Direct-Detection Optical OFDM

Zhang, Rong; Hanzo, Lajos

doi:10.1364/jocn.5.001402

Cited by 26 publications

(18 citation statements)

References 32 publications

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“…In this paper, we propose a two-stage MT pairing algorithm, relying on the cell association stage and on an exhaustive search stage. In the first stage, each MT measures its the distance to all LED lights and sets up a connection with the LED light at the shortest distance 6 . As a result, this MT is associated with the cell covered by the LED light assigned.…”

Section: A Link Characteristicsmentioning

confidence: 99%

Resource Allocation Under Delay-Guarantee Constraints for Visible-Light Communication

Jin

Zhang

et al. 2016

IEEE Access

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Visible Light Communications (VLC) relying on commercially available Light-Emitting Diode (LED) transmitters offer a huge data rate potential in this license-free spectral domain, whilst simultaneously satisfying energy-efficient conventional illumination demands. In a LED based VLC system, the achievable data rate may be severely degraded owing to the interference, when the VLC system employs the Unity Frequency Reuse (UFR) approach. In order to mitigate the effects of interference, we propose a pair of interference avoidance approaches, namely Frequency Reuse (FR) based transmission and Vectored Transmission (VT). Furthermore, the Resource Allocation (RA) problems of indoor Mobile Terminals (MTs) are investigated based on different transmission strategies. Inspired by the concept of Effective Capacity (EC), we formulate our RA optimization problems applying proportional fairness, while satisfying specific statistical delay constraints. Our optimization procedure solves the resource allocation problem of indoor MTs with the aid of a decentralized algorithm. Simulation results are also presented for quantifying the performance of the proposed algorithm. It is shown that both of our interference avoidance approaches are capable of reducing the interference, hence improving the overall performance. Furthermore, it is also observed that our VT transmission is capable of achieving a higher effective capacity than the FR approach, when the statistical delay requirements are loose. By contrast, the FR based transmission attains the best performance, when we tighten the delay requirements.

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Section: A Link Characteristicsmentioning

confidence: 99%

Resource Allocation Under Delay-Guarantee Constraints for Visible-Light Communication

Jin

Zhang

et al. 2016

IEEE Access

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“…It has been considered as a promising complementary technique to radio frequency counterpart due to its distinct advantages such as license-free spectrum, high data rate, low power consumption and high privacy protection [1,2]. Recently, orthogonal frequency division multiplexing (OFDM) has also been employed in OWC systems because of its inherent resistance to inter symbol interference (ISI), high spectral efficiency, and simple one-tap equalization [3,4], whereby gigabit/s point-topoint optical wireless transmission rates have been reported in [5][6][7][8]. Since the state-of-the-art work usually focuses on point-to-point optical wireless links, the same scenario is considered throughout this paper.…”

Section: Introductionmentioning

confidence: 99%

Layered ACO-OFDM for intensity-modulated direct-detection optical wireless transmission

Wang¹,

Chen²,

Guo³

et al. 2015

Opt. Express

197

167

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Layered asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) with high spectral efficiency is proposed in this paper for optical wireless transmission employing intensity modulation with direct detection. In contrast to the conventional ACO-OFDM, which only utilizes odd subcarriers for modulation, leading to an obvious spectral efficiency loss, in layered ACO-OFDM, the subcarriers are divided into different layers and modulated by different kinds of ACO-OFDM, which are combined for simultaneous transmission. In this way, more subcarriers are used for data transmission and the spectral efficiency is improved. An iterative receiver is also proposed for layered ACO-OFDM, where the negative clipping distortion of each layer is subtracted once it is detected so that the signals from different layers can be recovered. Theoretical analysis shows that the proposed scheme can improve the spectral efficiency by up to 2 times compared with conventional ACO-OFDM approaches with the same modulation order. Meanwhile, simulation results confirm a considerable signal-to-noise ratio gain over ACO-OFDM at the same spectral efficiency. 265-298 (1997). 10. J. B. Carruthers and J. M. Kahn, "Multiple-subcarrier modulation for nondirected wireless infrared communication," IEEE J. Sel. Areas Commun. 14(3), 538-546 (1996)

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“…Orthogonal frequency division multiplexing (OFDM) is one of the popular physical layer schemes utilized in a wide range of RF communications, and it is also considered as a candidate for IM/DD optical systems, since OFDM has inherent benefits such as high spectral efficiency, resistance to frequency-selective channels and simple one-tap equalization [12]- [14]. Hermitian symmetry is commonly imposed on the input data of the OFDM block to generate real-valued timedomain output signals [14].…”

Section: Introductionmentioning

confidence: 99%

Asymmetrically Clipped Absolute Value Optical OFDM for Intensity-Modulated Direct-Detection Systems

Bai

Wang

Hanzo

2017

J. Lightwave Technol.

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Abstract-Orthogonal frequency division multiplexing (OFD-M) is attracting increasing attention in optical communication systems thanks to the inherent benefits such as high spectral efficiency and resistance to frequency-selective channels. In this paper, a novel energy and spectrally efficient scheme called asymmetrically clipped absolute value optical OFDM (AAO-OFDM) is proposed for intensity-modulated direct-detection (IM/DD) systems. In AAO-OFDM, absolute value optical OFDM (AVO-OFDM) signals on the even subcarriers and asymmetrically clipped optical OFDM (ACO-OFDM) signals on the odd subcarriers are combined for simultaneous transmission, which employs all the subcarriers requiring no DC biases. For AVO-OFDM scheme, the frequency symbols are firstly modulated on the even subcarriers, which are then fed into an inverse fast Fourier transform block. Afterwards, the absolute values of the bipolar time-domain signals are taken to guarantee nonnegativity, while their signs are mapped to the complex-valued symbols and modulated on the odd subcarriers. Since there remain unused odd subcarriers, other useful symbols can be modulated on them, which leads to the conventional ACO-OFDM scheme. At the receiver, the ACO-OFDM symbols on the odd subcarriers are demodulated firstly, which are reconstructed and removed from the received signals. Afterwards, the remaining signals are utilized to detect the AVO-OFDM symbols with the aid of the demodulated sign symbols on the odd subcarriers. Theoretical analysis and simulation results show that AAO-OFDM has lower peak-to-average power ratio than other optical OFDM schemes, which makes it less sensitive to the nonlinearity of the optical devices. Furthermore, it achieves better bit error rate performance compared to its counterparts for the same spectral efficiency.Index Terms-Intensity modulation with direct detection, orthogonal frequency division multiplexing, energy efficiency, spectral efficiency.

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Multi-layer Modulation for Intensity-Modulated Direct-Detection Optical OFDM

Cited by 26 publications

References 32 publications

Resource Allocation Under Delay-Guarantee Constraints for Visible-Light Communication

Resource Allocation Under Delay-Guarantee Constraints for Visible-Light Communication

Layered ACO-OFDM for intensity-modulated direct-detection optical wireless transmission

Asymmetrically Clipped Absolute Value Optical OFDM for Intensity-Modulated Direct-Detection Systems

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