Signal Shaping and Modulation for Optical Wireless Communication

Dimitrov, Svilen; Sinanović, Sinan; Haas, Harald

doi:10.1109/jlt.2012.2188376

Cited by 83 publications

(39 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The analysis of power requirement for equalization and OFDM is beyond the scope of the paper. Interested reader can refer to [20][21][22]. However, the demonstrator allows these schemes to be implemented, so that detailed experimental comparisons can be made.…”

Section: B Snr Analysis Of L-pam Considering Transmitter and Receivementioning

confidence: 99%

High-Speed Integrated Visible Light Communication System: Device Constraints and Design Considerations

Rajbhandari

Chun

Faulkner

et al. 2015

IEEE J. Select. Areas Commun.

Self Cite

118

View full text Add to dashboard Cite

Abstract-Visible light communications (VLC) has the potential to play a major part in future smart home and next generation communication networks. There is significant ongoing work to increase the achievable data rates using VLC, to standardize it and integrate it within existing network infrastructures.The future of VLC systems depends on the ability to fabricate low cost transceiver components and to realize the promise of high data rates. This paper reports the design and fabrication of integrated transmitter and receiver components. The transmitter uses a two dimensional individually addressable array of micro light emitting diodes (µLEDs) and the receiver uses an integrated photodiode array fabricated in a CMOS technology. A preliminary result of a MIMO system implementation operating at a data rate of ~1Gbps is demonstrated. This paper also highlights the challenges in achieving highly parallel data communication along with the possible bottlenecks in integrated approaches. IndexTerms-Visible light communications, Optical communication system design, multiple input multiple output, optical wireless communications, link budget analysis, integrated optical system design.

show abstract

Section: B Snr Analysis Of L-pam Considering Transmitter and Receivementioning

confidence: 99%

High-Speed Integrated Visible Light Communication System: Device Constraints and Design Considerations

Rajbhandari

Chun

Faulkner

et al. 2015

IEEE J. Select. Areas Commun.

Self Cite

118

View full text Add to dashboard Cite

show abstract

“…A real bipolar time-domain OFDM signal follows a Gaussian distribution with average electrical power of E{s 2 (t)}=σ 2 s , where σ s is the standard deviation of the time-domain waveform s(t) [8,17]. Therefore, half of the time-domain samples in a U-OFDM signal follow a Gaussian distribution truncated at zero, and the other half of the samples are equal to zero [7,8].…”

Section: Electrical Powermentioning

confidence: 99%

OFDM-Based Visible Light Communications

Tsonev

Islim

Haas

2016

Signals and Communication Technology

Self Cite

View full text Add to dashboard Cite

This chapter provides an overview of latest enhancements of the orthogonal frequency division multiplexing (OFDM) based visible light communications. The principals of OFDM techniques for intensity modulation and direct detection (IM/DD) systems are explained in details in [1]. A number of inherently unipolar OFDM techniques were recently proposed as power efficient alternatives to the widely deployed direct-current-biased optical orthogonal frequency division multiplexing (DCO-OFDM). The unipolar orthogonal frequency division multiplexing (U-OFDM) technique achieves higher power efficiency compared to DCO-OFDM. However, due to the spectral efficiency loss of U-OFDM technique, the power efficiency advantage over DCO-OFDM starts to decrease as the spectral efficiency increases. Multiple U-OFDM streams are superimposed in enhanced unipolar orthogonal frequency division multiplexing (eU-OFDM) to double the spectral efficiency of U-OFDM technique. For the first time, the novel eU-OFDM allows unipolar OFDM techniques to have same spectral efficiency of DCO-OFDM. In this chapter, the concept of eU-OFDM is generalized to GeneRalizEd ENhancEd UnipolaR OFDM (GREENER-OFDM), and extended to other unipolar OFDM schemes (asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) and pulse-amplitude-modulated discrete multitone modulation (PAM-DMT)). IntroductionThe physical properties of commercially available light emitting diodes (LEDs) and photodiodes (PDs), which are the foremost candidates for low-cost front-end devices in optical wireless communications (OWC), allow OWC to be realised as Dobroslav Tsonev · Mohamed Sufyan Islim · Harald Haas Li-Fi Research and Development Centre, The University of Edinburgh, Edinburgh EH9 3JL, http://www.lifi-centre.com e-mail: h.haas@ed.ac.uk 1 2 Dobroslav Tsonev, Mohamed Sufyan Islim, and Harald Haas intensity modulation and direct detection (IM/DD) systems only. This is because light emitted by of-the-shelf LEDs is incoherent and so information can be reliably encoded only in the signal intensity. The phase and the amplitude of the light wave cannot be modulated or detected with LEDs and PDs. This limits the set of conventional modulation schemes that can be adopted from the field of radio frequency (RF) communications and directly translated into OWC. Signal modulation techniques such as on-off keying (OOK), pulse-position modulation (PPM), and M-ary pulse-amplitude modulation (M-PAM) are relatively straightforward to implement as they provide real signals that can be directly mapped to light intensity. However, as transmission rates increase, the limited modulation bandwidth of the front-end devices and the limited bandwidth of the OWC channel lead to intersymbol interference (ISI) in the time-domain modulation signal. Hence, a technique such as orthogonal frequency division multiplexing (OFDM) becomes more appropriate as a modulation scheme. OFDM enables simple cost-effective equalisation with single-tap equalisers in the frequency-domain. In add...

show abstract

“…PAM is considered for single carrier techniques with non-linear decision feedback equalization (DFE) [12] and with both DFE and linear feedforward equalization (FFE) techniques [13]. It was shown for an infra-red multi-path channel that DCO-OFDM outperforms PAM with FFE, however, PAM with DFE performs better than DCO-OFDM [13].…”

Section: Introductionmentioning

confidence: 99%

PAM-SCFDE for Optical Wireless Communications

Nuwanpriya

Zhang

et al. 2015

J. Lightwave Technol.

View full text Add to dashboard Cite

Multipath dispersion is a serious challenge in visible light communication (VLC) systems as these systems are used for indoor applications where there can be many reflections of the transmitted signal from the ceiling, walls, equipment, etc. These reflected signals cause intersymbol interference in the receiver and can degrade the performance of the system considerably. Orthogonal frequency-division multiplexing (OFDM) for optical wireless communications was introduced to mitigate multipath dispersion and has been well investigated in the literature. Recently, single-carrier systems with frequency-domain equalization (SCFDE) have been proposed as alternatives to OFDM. In this paper, we present pulse amplitude modulated SCFDE (PAM-SCFDE) to mitigate multipath dispersion in VLC systems. We also compare the proposed PAM-SCFDE with existing OFDM and SCFDE techniques for optical wireless communications in terms of analytical and simulated bit-error-rate (BER) performance, power-spectral efficiency, peak-to-average power ratio (PAPR), and overall system complexity. The proposed PAM-SCFDE requires lower per bit signal-to-noise ratio to achieve a BER of 10 −4 or smaller for modulation sizes common in practice, both with and without considering the effects of light-emitting diode transmitters, such as nonlinearity, forward current restriction, and bandwidth limitation. Furthermore, it exhibits better power efficiency for data rates less than 3 bit/s/Hz, lower PAPR and system complexity compared to other systems.Index Terms-Optical wireless communications, pulse amplitude modulation (PAM), single carrier systems with frequency domain equalization (SCFDE), visible light communications.

show abstract

Signal Shaping and Modulation for Optical Wireless Communication

Cited by 83 publications

References 18 publications

High-Speed Integrated Visible Light Communication System: Device Constraints and Design Considerations

High-Speed Integrated Visible Light Communication System: Device Constraints and Design Considerations

OFDM-Based Visible Light Communications

PAM-SCFDE for Optical Wireless Communications

Contact Info

Product

Resources

About