LED nonlinearity mitigation in LACO-OFDM optical communications based on adaptive predistortion and postdistortion techniques

Elkarim, Mohammed Abd; Aly, Moustafa H.; Abdel-Kader, Hala M.; Elsherbini, M. M.

doi:10.1364/ao.432364

Cited by 16 publications

(9 citation statements)

References 34 publications

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“…Because of their high peak power, LED chips are susceptible to overheating. Consequently, the high PAPR of the OFDM signal should be reduced until it is fed into the transmitter LEDs before it is sent [31,32].…”

Section: Severalmentioning

confidence: 99%

Non-Linear Companding Techniques With Aco-Ofdm-Based VLC Systems for Papr Reduction

Khalaf

Elnabawy

Azzam

2023

Journal of Advanced Engineering Trends

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In visible light communication (VLC) systems, optical orthogonal frequency division multiplexing (OOFDM) is used to reduce the effects of inter-symbol interference while simultaneously achieving fast data transmission speeds and large bandwidths. Asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) is one of the most OOFDM used. ACO-OFDM with low peak-to-average power ratio performance becomes essential for practical visible light communication broadcasting systems due to non-linearity elimination. The techniques for reducing the peak-to-average power ratio for visible light communication broadcasting systems are designed, simulated, and evaluated in this work. This work provides novel mixed Non-Liner Companding Techniques that target remarkable peak-toaverage power ratio performance with acceptable bit error rate performance for ACO-OFDMbased VLC systems. This work compares the designed techniques then nominates an optimum one that provides the optimum peak-to-average power ratio and bit error rate performance. Finally, the nominated technique will be compared to all related literatuers of ACO-OFDM-based VLC systems to ensure its novelty, validity, and effectiveness.

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Section: Severalmentioning

confidence: 99%

Non-Linear Companding Techniques With Aco-Ofdm-Based VLC Systems for Papr Reduction

Khalaf

Elnabawy

Azzam

2023

Journal of Advanced Engineering Trends

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“…In addition, it has been shown that the temperature also strongly contributes to the efficiency droop by promoting mechanisms such as carrier leakage, Auger recombination, and carrier delocalization [32]. The static nonlinearity model was adopted to estimate the impact of LED nonlinearity in OFDM [18], [19], optimize bias point [33] and to design nonlinear predistorters [20], [34]. Often the static nonlinearity is described with the Rapps model, originally devised for RF power amplifiers [28].…”

Section: A Led Modelsmentioning

confidence: 99%

“…The nonlinearity of LEDs is often misunderstood and the models found in the literature tend to either oversimplify or overcomplicate the matter. For example, some models assume that the nonlinear distortion is static and the instantaneous relationship between the current input to the LED and the output optical power can be described by a polynomial [17]- [20]. Other authors agree that the memory effects reported in multiple papers cannot be neglected and the LED must be modeled as a dynamic nonlinear system [16], [21]- [25].…”

Section: Introductionmentioning

confidence: 99%

A Behavioral Model of the Light Emitting Diode Nonlinearity

Bojarczuk¹,

Marzęcki²,

Sun³

et al. 2023

Preprint

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<p>Correct modeling of light emitting diode (LED) nonlinearity is vital for evaluating the performance of advanced modulation formats and nonlinear distortion mitigation methods in visible light communication systems. In this paper, we review the existing simplified nonlinear LED models: static polynomial, Wiener and Hammerstein and provide strong experimental evidence against their even coarse correctness. Instead, we propose an evenly uncomplicated model of LED, which is based on rigorous factorization of the Volterra 2nd order kernel stemming from the recombination rate equations of the LED. We further experimentally validate this model in four different LEDs by: (i) finding that linear transmitter pre-emphasis, against the results of the communications theory in a linear, bandlimited channel, can at very high input powers improve the transmission perfromance compared to linear equalization at the receiver, which is explained in our model by a reduction of the nonlinear distortion by the pre-emphasis; (ii) by comparing the measured 2nd order quadratic kernels of LEDs in regular form and with the constraints of our model. Finally, we propose a two-parameter calibration method of our model, which requires measurement of the LED bandwidth and 2nd order harmonic distortion at a single frequency. Excellent convergence of the signal transmitted in the calibrated model to the rate equation model and to the measurement is observed.</p>

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“…After the heating stage, the powder stays in the furnace and is cooled down to room temperature before being was with deionized water to get rid of the residues. After that, it is put into a drying oven and heated at 80 o C for 5h (Xi et al, 2021;Elkarim et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

Utilization of BaAl1.4Si0.6O3.4N0.6:Eu2+ Green-emitting Phosphor to Improve Luminous Intensity and Color Adequacy of White Light-emitting Diodes

Thai¹,

Bui²,

Le³

et al. 2023

IJTech

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BaAl1.4Si0.6O3.4N0.6:Eu 2+ exhibiting broad excitation and emission bands with intense green emission centred at 510 nm is applied to produce high-performance white-light-emitting diodes (WLEDs). The preparation of the green phosphor utilizes NaNO3 molten salt to attain the purity phase and enhanced luminescence strength boosting the crystalline growth. The influences of BaAl1.4Si0.6O3.4N0.6:Eu 2+ on the lighting intensity and color adequacy are investigated at three correlated color temperatures (CCTs) of 3000 K, 4000 K and 5000 K. The lighting output of the WLEDs with high CCTs (4000 -5000 K) is deemed as enhanced with increasing green-phosphor concentration. The lower CCT shows greater lumen output when using a lower concentration of BaAl1.4Si0.6O3.4N0.6:Eu 2+ . This tendency also takes place in the case of color uniformity. Conversely, the high concentration of the phosphor is not favourable to the color rendition property of the WLED because of the excessive green-light proportion. It is recommended to keep the concentration of BaAl1.4Si0.6O3.4N0.6:Eu 2+ staying below 10 wt% for better color fidelity.

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LED nonlinearity mitigation in LACO-OFDM optical communications based on adaptive predistortion and postdistortion techniques

Cited by 16 publications

References 34 publications

Non-Linear Companding Techniques With Aco-Ofdm-Based VLC Systems for Papr Reduction

Non-Linear Companding Techniques With Aco-Ofdm-Based VLC Systems for Papr Reduction

A Behavioral Model of the Light Emitting Diode Nonlinearity

Utilization of BaAl1.4Si0.6O3.4N0.6:Eu2+ Green-emitting Phosphor to Improve Luminous Intensity and Color Adequacy of White Light-emitting Diodes

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