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1

City lights revolution : next-gen optical fibre for smart cities

Yaseen Zeyad T., Alghrairi Mokhalad

Opto-Electronics Review

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2024

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Vol. 32, No. 3

art. no. e150610

EN

In the rapidly evolving landscape of smart cities, the integration of advanced technologies is crucial for ensuring safety, optimizing traffic flow, and enhancing the urban living experience. Vehicle-to-vehicle (V2V) communication and visible light communication (VLC) have emerged as promising solutions to address these challenges. This paper explores the integration of V2V communication and VLC at smart pedestrian crosswalks to enhance pedestrian safety and traffic management in smart cities. It explores the impact of neighbouring vehicles on V2V-VLC performance and proposes novel methodologies to assess traffic density effects. Results indicate a significant chance of encountering nearby cars during rush hours, emphasizing the importance of these integrated systems for safety and mobility in urban environments. The outcomes show that the chance of running into extra cars in nearby lanes is independent of the particular lane and increases to 80% through rush hours, but falls to a lower amount than 20% through off-peak and initial morning hours.

2

Design and performance evaluation of vehicular visible light communication system under different weather conditions and system parameters

El-Mokadem Eslam S., Tawfik Nagwan I., Aly Moustafa H., El-Deeb Walid S.

Opto-Electronics Review

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2023

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Vol. 31, No. 2

art. no. e145580

EN

Vehicular visible light communication is an emerging technology that allows wireless communication between vehicles or between vehicles and infrastructure. In this paper, a vehicular visible light communication system is designed using a non-return to zero on-off keying modulation scheme under the effect of different weather conditions such as clear, haze, and fog. The first model is a light emitting diode-based system and the second is a laser diode-based system. For both models, the influence of system parameters such as beam divergence, transceiver aperture diameters, and receiver responsivity is studied. The impact of the use of the trans-impedance amplifier is also investigated for both models. It was concluded that in the presence of the amplifier, output power of the light emitting diode and laser diode model are increased by 98.46 μW and 0.4719 W, respectively. The performance of the two proposed models is evaluated through bit error rate, quality factor, eye diagram, and output power to have some insightful results about the quality of service for the two proposed models. Under a specific weather condition, the performance of the system would be critical and other techniques should be applied. The maximum achievable link distance for the laser-based and light-emitting diode-based systems is 190 m at a data rate of 25 Gbps and 80 m at a data rate of 60 kbps, respectively, under the same system parameters and weather conditions. The obtained results provide a full idea about the availability of constructing our proposed model in a practical environment, showing a higher performance of the laser diode-based model than that of the light emitting diode-based model.

3

A complexity efficient PAPR reduction scheme for FBMC-based VLC systems

Roshdy Radwa A., Hussein Aziza I., Mabrook Mohamed M., Salem Mohammed A.

Opto-Electronics Review

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2023

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Vol. 31, No. 1

art. no. e144919

EN

Visible light communication based on a filter bank multicarrier holds enormous promise for optical wireless communication systems, due to its high-speed and unlicensed spectrum. Moreover, visible light communication techniques greatly impact communication links for small satellites like cube satellites, and pico/nano satellites, in addition to inter-satellite communications between different satellite types in different orbits. However, the transmitted visible signal via the filter bank multicarrier has a high amount of peak-to-average power ratio, which results in severe distortion for a light emitting diode output. In this work, a scheme for enhancing the peak-to-average power ratio reduction amount is proposed. First, an algorithm based on generating two candidates signals with different peak-to- average power ratio is suggested. The signal with the lowest ratio is selected and transmitted. Second, an alternate direct current-biased approach, which is referred to as the addition reversed method, is put forth to transform transmitted signal bipolar values into actual unipolar ones. The performance is assessed through a cumulative distribution function of peak-to-average power ratio, bit error rate, power spectral density, and computational complexity. The simulation results show that, compared to other schemes in literature, the proposed scheme attains a great peak-to-average power ratio reduction and improves the bit the error rate performance with minimum complexity overhead. The proposed approach achieved about 5 dB reduction amount compared to companding technique, 5.5 dB compared to discrete cosine transform precoding, and 8 dB compared to conventional direct current bias of an optical filter bank multicarrier. Thus, the proposed scheme reduces the complexity overhead by 15.7% and 55.55% over discrete cosine transform and companding techniques, respectively.

4

Feasibility study of using various optical filters in conjunction with indoor visible light communication system

Fadhil Hilal A., Alattar Feras Hasson, Fadil Tariq Adnan

Optica Applicata

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2023

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Vol. 53, nr 4

511--522

EN

In modern telecommunication engineering, visible light communication (VLC) is developing a competitive advantage over the traditional RF data communication model since it uses light to transmit data. Optical filters play an important role in optical communication systems to enhance the transmission rate of bit-error rate (BER), especially as a result of noisy environments. We investigate the VLC signal performance induced by four types of filters, including Bessel, Gaussian, rectangular, and trapezoidal filters. The BER is considered an important aspect of improving optical system performance, as it indicates less crosstalk and fewer interferences within the system and is analyzed using eye diagram opening penalties. In our simulation results, the Gaussian filter performs best among these four types of filters. In this paper, a VLC indoor model is developed and simulated using an eye diagram, a bit error rate, and a transmission distance for the proposed model. The results from this study show significant improvements of Gaussian filter over other optical filters for next-generation optical networking systems, the overall BER of a Gaussian filter-based indoor VLC system is less than 9.6×10–15, when the bandwidth of the optical filter is 5 nm at the quality factor of 14 dB.

5

Indoor localization based on visible light communication and machine learning algorithms

Ghonim Alzahraa M., Salama Wessam M., Khalaf Ashraf A. M., Shalaby Hossam M. H.

Opto-Electronics Review

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2022

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Vol. 30, No. 2

art. no. e140858

EN

An indoor localization system is proposed based on visible light communications, received signal strength, and machine learning algorithms. To acquire an accurate localization system, first, a dataset is collected. The dataset is then used with various machine learning algorithms for training purpose. Several evaluation metrics are used to estimate the robustness of the proposed system. Specifically, authors’ evaluation parameters are based on training time, testing time, classification accuracy, area under curve, F1-score, precision, recall, logloss, and specificity. It turned out that the proposed system is featured with high accuracy. The authors are able to achieve 99.5% for area under curve, 99.4% for classification accuracy, precision, F1, and recall. The logloss and precision are 4% and 99.7%, respectively. Moreover, root mean square error is used as an additional performance evaluation averaged to 0.136 cm.

6

Hybrid PAPR reduction schemes for different OFDM-based VLC systems

El-Ganiny Mohamed Y., Khalaf Ashraf A. M., Hussein Aziza I., Hamed Hesham F. A.

Opto-Electronics Review

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2022

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Vol. 30, No. 3

art. no. e141951

EN

Orthogonal frequency division multiplexing has been widely used in many radio frequency wireless communication standards as a preferable multicarrier modulation scheme. The modulated signals of a conventional orthogonal frequency division multiplexing system are complex and bipolar. In intensity-modulated direct detection optical wireless communications, transmitted signals should be real and unipolar due to non-coherent emissions of an optical light emitting diode. In this paper, different hybrid optical systems have been proposed to satisfy real and unipolar signals. Peak-to-average power ratio is one of the biggest challenges for orthogonal frequency division multiplexing-based visible light communications. They are based on a combination of non-linear companding techniques with spreading or precoding techniques. Simulation evaluation is performed under direct current-biased optical orthogonal frequency division multiplexing, asymmetrically clipped optical orthogonal frequency division multiplexing, and Flip-orthogonal frequency division multiplexing systems in terms of peak-to-average power ratio, bit error rate, and spectral efficiency. The proposed schemes are investigated to determine a scheme with a low peak-to-average power ratio and an acceptable bit error rate. MATLABTM software has been successfully used to show the validity of the proposed schemes.

7

A proposed preamble channel estimation scheme for flip FBMC-based indoor VLC systems

El-Ganiny Mohamed Y., Khalaf Ashraf A. M., Hussein Aziza I., Hamed Hesham F. A.

Opto-Electronics Review

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2022

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Vol. 30, No. 1

art. no. e140859

EN

Filter bank multicarrier waveform is investigated as a potential waveform for visible light communication broadcasting systems. Imaginary inter-carrier and/or inter-symbol interference are causing substantial performance degradation in the filter bank multicarrier system. Direct current-biased optical filter bank multicarrier modulation overcomes all the problems of direct current-biased optical-orthogonal frequency division multiplexing modulation approaches in terms of speed and bandwidth. However, it also wastes a lot of energy while transforming a true bipolar signal into a positive unipolar signal by adding direct current-bias. In this paper, a flip-filter bank multicarrier-based visible light communication system was introduced to overcome this problem. In this system, a bipolar signal is converted to a unipolar signal by isolating the positive and negative parts, turning them to positive and then delivering the signal. Also, a new channel estimation scheme for a flip-filter bank multicarrier system is proposed which improves the channel estimation performance compared to that of each of the conventional schemes. The proposed system performance is measured in terms of bit error rate, normalized mean squared error, and constellation diagram. The superiority of the proposed scheme over other conventional structures has been successfully verified by MATLAB 2020b simulation experiments results. These results are evaluated under indoor visible light communication standard.

8

PAPR reduction using a combination between precoding and non-liner companding techniques for ACO-OFDM-based VLC systems

Mohammed Nazmi A., Elnabawy M. M., Khalaf Ashraf A. M.

Opto-Electronics Review

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2021

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Vol. 29, No. 2

59--70

EN

Peak-to-average power ratio reduction techniques for visible light communication broadcasting systems are designed, simulated, and evaluated in this work. The proposed techniques are based on merging non-linear companding techniques with precoding techniques. This work aims to nominate an optimum novel scheme combining the low peak-to-average power ratio with the acceptable bit error rate performance. Asymmetrically clipped optical orthogonal frequency division multiplexing with the low peak-to-average power ratio performance becomes more attractive to real-life visible light communication applications due to non-linearity elimination. The proposed schemes are compared and an optimum choice is nominated. Comparing the presented work and related literature reviews for peak-to-average power ratio reduction techniques are held to ensure the proposed schemes validity and effectiveness.

9

Dimming control schemes combining IEEE 802.15.7 and SC-LPPM modulation schemes with an adaptive M-QAM OFDM for indoor LOS VLC systems

Mohammed Nazmi A., Badawi Kareem A., Khalaf Ashraf A. M., El-Rabaie El-Sayed

Opto-Electronics Review

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2020

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Vol. 28, No. 4

203--212

EN

The presented work proposes a new dimming control schemes for indoor visible light communication which combines variable pulse-position modulation, colour shift keying as key schemes of IEEE 802.15.7 standard, and sub carrier-pulse-position modulation as a pulse-position modulation variant with orthogonal frequency division multiplexing. These schemes are then compared with traditional merging schemes utilizing pulse-width modulation and multiple pulse-position modulation with m-ary quadrature amplitude modulation OFDM. The proposed schemes are investigated in a typical room with a different lighting layout (i.e., distinctive and uniform lighting layout), followed by an illumination investigation to evaluate the performance of the proposed schemes, especially the enhanced achieved data rates, and to determine their limitations as reliable visible light communication systems that can satisfy both communication and illumination requirements.

10

Praktyczna implementacja steganografii w VLC

Januszewski P., Stępniak G., Szczypiorski K.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2017

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nr 8-9

693--696, CD

PL

W tym referacie przedstawiamy wyniki pierwszej (według naszej wiedzy) praktycznej implementacji steganografii w systemie komunikacji poprzez światło widzialne (VLC). VLC jest to nowy, tani, bezprzewodowy system transmisji danych, który wykorzystuje fale z zakresu światła widzialnego. Testy eksperymentalne wykazały, że jesteśmy w stanie uzyskać transmisję steganograficzną o szybkości około 1 Mbit/s(wykorzystując technikę DS-CDMA) ukrytą w jawnej transmisji danych o szybkości 110 Mbit/s przesyłanej za pomocą modulacji PPM.

EN

In this paper we describe first (to our knowledge) practical implementation of steganography in visible light communication (VLC). VLC is a new low-cost wireless data transmission system, which employs the visible light spectrum. Our experimental results shows that we are able to achieve approximately 1 Mbit/s steganographic transmission (using DS-CDMA technique) hidden in 110 Mbit/s overt data stream send with PPM modulation.