Adaptive predistortion technique for nonlinear LED with dimming control in VLC system

Aggarwal, Parag; Ahmad, Rizwana; Srivastava, Anand

doi:10.1109/ants.2017.8384165

Cited by 11 publications

(5 citation statements)

References 31 publications

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“…subcarriers or modulation sizes, peak-to-average power ratio (PAPR) can be kept small [28]. For large values of K , PAPR reduction techniques can be employed [29], [30] or optimal selection of DC bias can be performed [31]. All system parameters used in simulations are listed in Table 3.…”

Section: Simulation Resultsmentioning

confidence: 99%

Resource Allocation for Visible Light Communication Systems Using Simulated Annealing Based on a Problem-Specific Neighbor Function

et al. 2019

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In this paper, we consider a visible light communication (VLC) system with direct currentbiased orthogonal frequency division multiplexing (DC-OFDM) and investigate resource allocation for a multi-user environment. Based on the user satisfaction index as a function of data rate, we aim to optimally determine the allocation of the users to different LEDs (acting as access points) and OFDM subcarriers. We propose a simulated annealing-based heuristic to maximize the average user satisfaction index. In an effort to make the proposed solution practically feasible, the runtime of the proposed heuristic is kept less than the channel coherence time, whose value is in order of tens of milliseconds. We evaluate the performance of the proposed heuristic algorithm in different scenarios that vary in the number of users, the number of LEDs, and the separation between users. Our results demonstrate that the proposed heuristic outperforms other wellknown heuristics (such as standard simulated annealing, iterative greedy, particle swarm optimization, and tabu search) while achieving good quality solutions within a short execution time, i.e., 40-80 ms.INDEX TERMS Visible light communications, resource allocation, optimization, simulated annealing, heuristics.

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Section: Simulation Resultsmentioning

confidence: 99%

Resource Allocation for Visible Light Communication Systems Using Simulated Annealing Based on a Problem-Specific Neighbor Function

et al. 2019

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“…Wiener model 26 is adopted to describe the memory effect of nonlinear LED in Fig. 2, which is composed of a linear time-invariant (LTI) block followed by a memoryless nonlinearity (NL) block 27 …”

Section: System Modelmentioning

confidence: 99%

“…2, which is composed of a linear time-invariant (LTI) block followed by a memoryless nonlinearity (NL) block. 27 The memory effect of the LTI block is expressed as E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 0 4 ; 1 1 6 ; 6 5 1…”

Section: System Modelmentioning

confidence: 99%

Combined kernel with parameter optimization for least squares support vector machine postdistorter in visible light communications

et al. 2023

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.The nonlinearity and memory effects induced by light-emitting diode distort the transmitted signal, which significantly limits the performance of visible light communication (VLC) system. With the characteristics of low computational complexity, fast convergence speed, and strong generalization ability, least squares support vector machine (LSSVM) is investigated in this paper and employed to alleviate the nonlinear effect. Since the performance of LSSVM is largely determined by the type of the adopted kernel functions, we utilize Gaussian and Laplace functions and propose a new combined kernel, which can increase the reproducing kernel Hilbert space and thus enhance the global expressive power compared with conventionally used Gaussian kernel. To further improve the performance, a hybrid parameter optimization algorithm is exploited to optimize the proposed kernel, based on genetic algorithm and particle swarm optimization. The property of the proposed postdistortion method is verified by numerical simulations, and better performance is obtained in VLC systems compared with the Gaussian-kernel LSSVM and conventional memory polynomial method.

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“…The nonlinearity of VLC systems mainly stems from LED, whose number of emitted photos is disproportional to the injected current amplitude. Moreover, since the carrier-density response is indeed frequency-dependent, LED also shows obvious memory effect, especially when a large modulation bandwidth is considered [18]. To describe a general model for the nonlinearity and memory effect, the Volterra series has been exploited, which can be given as [19] in the following ) kk h q q stands for the k -th Volterra kernel, and Q denotes the memory depth.…”

Section: B Nonlinearity Of Ledmentioning

confidence: 99%

High-Dimensional Radial Basis Function Extension Interpolation Nonlinear Post-Distorter in Visible Light Communication Systems

et al. 2022

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The nonlinearity induced by light-emitting diode (LED) affects the normal transmission and reception, which significantly limits the performance of visible light communication (VLC) system. To address the problem induced by the nonlinearity of LED, a post-distorter for orthogonal frequency division multiplexing (OFDM) based VLC is proposed in this paper. Radial basis function (RBF) interpolation, known as an excellent function approximation method, is investigated to implement the nonlinearity mitigations. To further remove the memory effect of LED, which could not be ignored, we propose to extend RBF to a high-dimensional interpolation so that it can eliminate both nonlinearity and memory effect simultaneously. The performance of the proposed RBF extension interpolation is verified by numerical simulations, and a better performance in suppressing nonlinearity is obtained in VLC-OFDM systems as compared with the frequency domain nonlinear compensation method. A signalto-noise ratio gain of 2dB in terms of 0 bEN can be obtained when bit error rate is about 6*10 -7 at 6dB power back-off (PBO), while 6dB gain can be achieved when BER is 2*10 -4 at 4dB PBO.

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Adaptive predistortion technique for nonlinear LED with dimming control in VLC system

Cited by 11 publications

References 31 publications

Resource Allocation for Visible Light Communication Systems Using Simulated Annealing Based on a Problem-Specific Neighbor Function

Resource Allocation for Visible Light Communication Systems Using Simulated Annealing Based on a Problem-Specific Neighbor Function

Combined kernel with parameter optimization for least squares support vector machine postdistorter in visible light communications

High-Dimensional Radial Basis Function Extension Interpolation Nonlinear Post-Distorter in Visible Light Communication Systems

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