scholarly journals Deep Learning-Assisted Index Estimator for Generalized LED Index Modulation OFDM in Visible Light Communication

Photonics ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 168
Author(s):  
Manh Le-Tran ◽  
Sunghwan Kim
Keyword(s):  
Deep Learning ◽  
Visible Light ◽  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Ofdm System ◽  
Signal Demodulation ◽  
Index Estimation ◽  
Index Modulation

In this letter, we present the first attempt of active light-emitting diode (LED) indexes estimating for the generalized LED index modulation optical orthogonal frequency-division multiplexing (GLIM-OFDM) in visible light communication (VLC) system by using deep learning (DL). Instead of directly estimating the transmitted binary bit sequence with DL, the active LEDs at the transmitter are estimated to maintain acceptable complexity and improve the performance gain compared with those of previously proposed receivers. Particularly, a novel DL-based estimator termed index estimator-based deep neural network (IE-DNN) is proposed, which can employ three different DNN structures with fully connected layers (FCL) or convolution layers (CL) to recover the indexes of active LEDs in a GLIM-OFDM system. By using the received signal dataset generated in simulations, the IE-DNN is first trained offline to minimize the index error rate (IER); subsequently, the trained model is deployed for the active LED index estimation and signal demodulation of the GLIM-OFDM system. The simulation results show that the IE-DNN significantly improves the IER and bit error rate (BER) compared with those of conventional detectors with acceptable run time.

scholarly journals Study of the Performance of Deep Learning-Based Channel Equalization for Indoor Visible Light Communication Systems

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 453
Author(s):  
Pu Miao ◽  
Weibang Yin ◽  
Hui Peng ◽  
Yu Yao
Keyword(s):  
Deep Learning ◽  
Visible Light ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Channel Equalization ◽  
Training Data ◽  
Traditional System ◽  
Ber Performance

The inherent impairments of visible light communication (VLC) in terms of nonlinearity of light-emitting diode (LED) and the optical multipath restrict bit error rate (BER) performance. In this paper, a model-driven deep learning (DL) equalization scheme is proposed to deal with the severe channel impairments. By imitating the block-by-block signal processing block in orthogonal frequency division multiplexing (OFDM) communication, the proposed scheme employs two subnets to replace the signal demodulation module in traditional system for learning the channel nonlinearity and the symbol de-mapping relationship from the training data. In addition, the conventional solution and algorithm are also incorporated into the system architecture to accelerate the convergence speed. After an efficient training, the distorted symbols can be implicitly equalized into the binary bits directly. The results demonstrate that the proposed scheme can address the overall channel impairments efficiently and can recover the original symbols with better BER performance. Moreover, it can still work robustly when the system is complicated by serious distortions and interference, which demonstrates the superiority and validity of the proposed scheme in channel equalization.

An approach to ensure joint illumination & communication performance of a forward error corrected indoor visible light communication (VLC) system in presence of ambient light interference

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sourish Chatterjee ◽  
Biswanath Roy
Keyword(s):  
Visible Light ◽  
Bit Error Rate ◽  
Error Rate ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Ambient Light ◽  
Ambient Illumination ◽  
Communication Performance ◽  
Light Interference ◽  
Forward Error

AbstractIn recent time of looming radio frequency (RF) spectrum crisis, visible light communication using lighting infrastructure emerged as a potential alternative at an indoor environment. This paper addresses the setback associated with ambient light interference in an indoor Visible Light Communication (VLC) system to ensure joint communication and illumination performance inside an office room. A novel VLC architecture with suitable white light emitting diode (WLED) luminaire arrangement is presented to minimize the dispersion of signal to interference plus noise ratio (SINR) across the room. Luminaires are categorized in two groups viz. data transmitting illuminants and illuminants for lighting purpose. The first group is dedicated to transmit data as well as serves the purpose of illumination. The other set creates only ambient illumination to achieve quality lighting attributes. The proposed forward error corrected receiver configuration discards the ambient light noise originated by the illuminants that serve the ambient illumination. Tail biting convolutional encoder and viterbi decoder are used at the encoding section of the transmitter and decoding section of the receiver respectively to improve bit error rate. Results obtained through MATLAB simulation shows better average bit error rate (BER) in the order of 10−8 measured at uniformly distributed 25 grid points over the working plane. At the same time achieved average horizontal illuminance with good uniformity comply with ISO recommendation.

scholarly journals A Full-Duplex LED-to-LED Visible Light Communication System

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1713
Author(s):  
Hyunwoo Jung ◽  
Sung-Man Kim
Keyword(s):  
Visible Light ◽  
Bit Error Rate ◽  
Error Rate ◽  
Signal To Noise Ratio ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Full Duplex ◽  
Signal To Noise ◽  
Light Emitting ◽  
Half Duplex

We experimentally demonstrated full-duplex light-emitting diode (LED)-to-LED visible light communication (VLC) using LEDs as the transmitter and receiver. Firstly, we investigated the performance dependency on the wavelengths of the LED transmitter and receiver by measuring the rise time and signal-to-noise ratio (SNR). Through the investigation, we were able to choose the optimal LED color set for LED-to-LED VLC using Shannon’s channel capacity law. The bit error rate (BER) results of full-duplex and half-duplex LED-to-LED VLC systems with the optimal LED sets are shown to compare the performance. Furthermore, we discuss major distortions and signal losses in the full-duplex LED-to-LED VLC system.

Quantitative analysis of the stacked autoencoder method in MIMO-ACO-OFDM VLC systems

2020 ◽  
pp. 147715352092620
Author(s):  
LL Hao ◽  
CD Li ◽  
DY Wang
Keyword(s):  
Visible Light ◽  
Bit Error Rate ◽  
Error Rate ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Visible Light Communication ◽  
Delay Spread ◽  
Rate Performance ◽  
Stacked Autoencoder ◽  
Minimum Mean Squared Error

In this paper, a stacked autoencoder network is utilised to realise the signal constellation and transceivers adapted to the dimmable indoor visible light communication system in order to acquire lower symbol error probability. Its decoder parts function as denoising and the equaliser for the proposed multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) visible light communication system which can compensate the non-linear transfer function and the crosstalk between multiple LED data streams. The bit error rate performance as well as the influence of LED spatial intervals on root mean square delay spread, impulse response and bit rate have been analysed considering multipath reflections of the indoor MIMO-VLC system. The numerical results show that the a stacked autoencoder technique performs better in bit error rate reduction compared with state-of-art the zero forcing and minimum mean squared error algorithm. The experiment also shows, when the semi-angle at half power of LEDs and the field of view of Photodetectors become small, better performance can be achieved at the centre of the room, which can be explained by strong beam converge and the decreased multipath interference. Moreover, enlarging the separation between LEDs leads to improved bit error rate performance and reduced channel correlation of channel matrix, which need to be optimally chosen in practice.

scholarly journals A Novel Transceiver Model for Polar Transform Optical (PTO-) OFDM for Visible Light Communication (VLC) Based on Peak to Average Power Ratio Reduction using Precoding

2020 ◽  
Vol 9 (10) ◽  
pp. 307-315
Keyword(s):  
Visible Light ◽  
Power Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Light Emitting Diode ◽  
Average Power ◽  
Visible Light Communication ◽  
Intensity Modulation ◽  
Power Ratio ◽  
Positive Real ◽  
High Data

Indoor visible light communication (VLC) has the potential of providing high data rates for short-range wireless communication with a relative spatial elevated security in contrast to a radiofrequency wireless one. To support that high data stream, Orthogonal Frequency Division Multiplexing (OFDM) is used; however, due to the limited operational bandwidth of the commercial white light-emitting diode (LED), signal processing techniques are used to increase the efficiency of the OFDM and to adapt OFDM to VLC systems. As a major concern, the intensity modulation direct detection necessary for VLC requires positive real signal, this is dealt with by imposing Hermitian pre-possessing or Cartesian to polar conversion post-processing to the OFDM. The use of the Cartesian to polar converter allows the transmission of complex OFDM symbols through the intensity modulation channel. A polar transform optical (PTO-) OFDM presented here as an improvement and simplification of previous polar optical OFDM schemes gives an efficient transceiver architecture. Nevertheless, both OFDM transmission techniques for Visible optical links, similar to radiofrequency (RF), suffer greatly from irregular excessive Peak-to-Average power ratio (PAPR). Higher PAPR reduces the power efficiency of the On-Off Keying (OOK) based on pulse amplitude modulation (PAM). Furthermore, it also is recommendable to reduce the PAPR for conformity with eye safety. A precoding technique is proposed to reduce the PAPR of intensity-modulated for direct detectability of the OFDM signal destined for the wireless optical link using Cartesian-to-Polar conversion. Based on the enhanced processing at the front ends and using MATLAB simulation, it is proven that the presented model can improve the link parameters including the bit error rate (BER) and signal to noise ratio (SNR) and bandwidth efficient compared to Hermitian modified ones.

The Research of High-Level Modulation in Visible Light Communication

2013 ◽  
Vol 850-851 ◽  
pp. 516-519
Author(s):  
Zi Qiang Hao ◽  
Hong Zuo Li ◽  
Ting Zhao
Keyword(s):  
Visible Light ◽  
Wavelength Division Multiplexing ◽  
Error Rate ◽  
Communication System ◽  
Transmission Rate ◽  
Light Emitting Diode ◽  
Average Power ◽  
Visible Light Communication ◽  
Bandwidth Efficiency ◽  
High Level

Visible light communication system using light emitting diode as light source, the system has the dual role of lighting and communication, thereby greatly saving energy .The bandwidth of LED modulation is a major obstacle to development of VLC technology. Researchers have put forward a variety of techniques to extend the modulation bandwidth and improve the transmission rate, such as Blu-ray filtering, equalization, multiple-input multiple-output (MIMO) technology, high ray modulation format, the wavelength division multiplexing technology, discrete multi-tone modulation and so on. The transmission rate of VLC system can be greatly improved by a combination of these techniques in a technical or several techniques. This paper analyzes the effect of OFDM technology each sub-carrier modulation with MQAM to visible light communication. It gives a brief introduction of the visible light communication system; it also shows the average power spectral density and error rate from SIMULINK simulation. It proves further the high-level quadrature amplitude modulation (MQAM) with higher bandwidth efficiency and smaller error rate, the bandwidth efficiency of 256QAM modulation is the twice of 16QAM modulation.

scholarly journals I Implementasi Sistem Hermitian Generalized LED Index Modulation (H-GLIM-OFDM) pada Board FPGA Xilinx Arty Artix-7

Electrician ◽  
2020 ◽  
Vol 14 (3) ◽  
pp. 100-111
Author(s):  
Yetti Yuniati
Keyword(s):  
Visible Light ◽  
Field Programmable Gate Array ◽  
Orthogonal Frequency Division Multiplexing ◽  
Visible Light Communication ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Transfer Data ◽  
System Generator ◽  
Field Programmable ◽  
Index Modulation

Abstrak— Komunikasi nirkabel menjadi jenis komunikasi yang digunakan secara luas, spektrum radio yang umumnya digunakan dalam komunikasi nirkabel menjadi tidak cukup untuk memenuhi tuntutan yang tinggi. Visible Light Communication (VLC) menjadi solusi untuk mengatasi kapasitas bandwidth yang kurang memadai ini. Orthogonal Frequency Division Multiplexing (OFDM) menjadi teknik yang dikembangkan untuk sistem komunikasi cahaya tampak karena pada teknik OFDM frekuensi yang digunakan saling orthogonal dan memungkinkan overlap antar frekuensi tanpa menimbulkan interferensi satu sama lain sehingga menghasilkan kecepatan transfer data yang tinggi. Jurnal ini membahas tentang Implementasi Sistem Hermitian Generalized LED Index Modulation (H-GLIM-OFDM). Skema dari H-GLIM-OFDM ini dirancang dalam System Generator pada bahasa pemograman Matlab. Desain di implementasikan dalam FPGA dan diterapkan dengan spesifikasi Arty Board Xilinx Artix-7. Field Programmable Gate Array (FPGA) merupakan perangkat semikonduktor yang dapat diprogram secara fleksibel dan dapat melakukan kinerja yang tinggi untuk implementasi VLC. Hasil yang didapat pada simulasi ini yaitu menggunakan pemanfaatan sumber daya desain 5% BRAM, 11% dari DSP, 8% dari LUT, 18% dari IO, dan 3% BUFG.   Kata Kunci : H-GLIM-OFDM, FPGA Arty Artix-7, Visible Light Communication, Vivado, System Generator

scholarly journals Experimental Investigation of Zadoff-Chu Matrix Precoding for Visible Light Communication System with OFDM Modulation

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Xinyue Guo ◽  
Yang Guo ◽  
Shuangshuang Li
Keyword(s):  
Visible Light ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Forward Error Correction ◽  
Signal To Noise Ratio ◽  
Light Emitting Diode ◽  
Average Power ◽  
Visible Light Communication ◽  
Potential Candidate ◽  
Ofdm Modulation

Light-emitting diode- (LED-) based visible light communication (VLC) has become a potential candidate for next generation high-speed indoor wireless communication. Due to the limited modulation bandwidth of the LED, orthogonal frequency division multiplexing (OFDM) modulation is particularly preferred in the VLC system to overcome the ISI, which suffers from the high peak-to-average power ratio (PAPR) and leads to severe performance loss. In this paper, we propose and experimentally demonstrate a novel Zadoff-Chu matrix (ZCM) precoding scheme, which can not only reduce the PAPR, but also provide uniform signal-to-noise ratio (SNR) profile. The theoretical analysis and simulation show that the proposed scheme achieves better PAPR performance compared with the traditional precoding schemes. The experimental demonstration further validates the bit error rate (BER) performance improvement, where the measured BERs are all below the 7% pre-forward error correction (pre-FEC) limit of 3.8 × 10−3 when the transmitted data rate is 50 Mb/s.

scholarly journals Li-Pos: A Light Positioning Framework Leveraging OFDM for Visible Light Communication

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4310
Author(s):  
Jianbin Wu ◽  
Sami Ahmed Haider ◽  
Muhammad Irshad ◽  
Jehangir Arshad ◽  
Sohail M. Noman ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Orthogonal Frequency Division Multiplexing ◽  
Pulse Width Modulation ◽  
Light Emitting Diode ◽  
Area Under The Curve ◽  
Visible Light Communication ◽  
Delay Spread ◽  
Entire Area ◽  
Receiver Plane

The design of solid-state lighting is vital, as numerous metrics are involved in their exact positioning, and as it is utilized in various processes, ranging from intelligent buildings to the internet of things (IoT). This work aims to determine the power and delay spread from the light source to the receiver plane. The positions of the light source and receiver were used for power estimation. We focus on analog orthogonal frequency-division multiplexing (OFDM) in visible light communication (VLC) and assess the area under the curve (AUC). The proposed system was designed using modulation techniques (i.e., quadrature amplitude modulation; QAM) for visible light communication (VLC) and pulse-width modulation (PWM) for dimming sources. For the positioning and spreading of brightness, the proof-of-concept was weighted equally over the entire area. Therefore, the receiver plane was analyzed, in order to measure the power of each light-emitting diode (LED) in a given area, using the delayed mean square error (MSE). A framework was applied for the placement of LEDs, using full-width at half-maximum (FWHM) parameters with varying distances. Then, the received power was confirmed. The results show that the AUC using DRMS values for LEDs significantly increased (by 30%) when the number of source LEDs was changed from four to three. These results confirm that our system, associated with the simple linear lateration estimator, can achieve better energy consumption.

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