scholarly journals PAPR Reduction Technique and BER Performance Improvement in OFDM-based Wireless Visible Light Communication

Author(s):  
Sang-Burm Ryu ◽  
Heung-Gyoon Ryu
2018 ◽  
Vol 39 (4) ◽  
pp. 427-435 ◽  
Author(s):  
Haitham Freag ◽  
Emad S. Hassan ◽  
Sami A. El-Dolil ◽  
Moawad I. Dessouky

Abstract Orthogonal frequency division multiplexing (OFDM) is used with visible light communication (VLC) systems to reduce the effects of inter-symbol interference (ISI) and to achieve communication with high speed of data transmission and huge bandwidth. However, OFDM-based VLC systems suffer from high peak-to-average power ratios (PAPRs). This paper proposes a new hybrid PAPR reduction technique based on signal transformation combined with clipping. The Hadamard transform is used in the proposed technique due to its advantages in reducing the PAPR without affecting the bit error rate (BER) of VLC systems. The optimum clipping threshold at which we can simultaneously reduce the PAPR and improve the BER of VLC systems is also determined. In this paper, we also propose a new OFDM structure based on using discrete cosine transform (DCT) precoding before inverse fast Fourier transform (IFFT) stage to further improve the PAPR reduction capability and BER performance. Several experiments are carried out to test the performance of the proposed technique in terms of complementary cumulative distribution function (CCDF) and the BER. The obtained results show that the proposed technique can simultaneously reduce the PAPR and achieve good BER performance when compared to the original OFDM-based VLC system.


Author(s):  
Ming-Wei Li ◽  
Jhih-Heng Yan ◽  
Chien-Ju Chen ◽  
Pin-Chao Huang ◽  
Kai-Chia Chen ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Zhongpeng Wang ◽  
Shoufa Chen

This paper proposes a physical encryption scheme for discrete cosine transform (DCT) precoded OFDM-based visible light communication systems by employing chaos scrambling. In the proposed encryption scheme, the Logistic map is adopted for the chaos mapping. The chaos scrambling strategy can allocate the two scrambling sequences to the real (I) and imaginary (Q) parts of OFDM frames according to the initial condition, which enhance the confidentiality of the physical layer. The simulation experimental results prove the efficiency of the proposed encryption method for DCT precoded OFDM-based VLC systems. The experimental results show that the proposed security scheme can protect the DCT precoded OFDM-based VLC from eavesdropper, while keeping the advantage of the DCT precoding technique, which can reduce the PAPR and improve the BER performance of OFDM-based VLC.


2021 ◽  
Vol 9 ◽  
Author(s):  
Agha Yasir Ali ◽  
◽  
Lubna Farhi ◽  
Usama Ahmed ◽  
Asad Subhan ◽  
...  

This paper focuses to analyze the data rate, bit error rate (BER), flickering & bandwidth of visible light communication (VLC) system. The existing modulation scheme ON-OFF Keying (OOK) is modified and produces the trade-off between these parameters. The modified ON-OFF Keying (MOOK) is proposed in which the variation in the transmitted pulses is investigated. Therefore, the square and rectangular pulses are used to transmit zero and one bits respectively. The duty cycle of square pulse is increased to improve the flickering performance. Moreover, it utilized the bandwidth and deteriorates the BER performance. The differential MOOK (DMOOK) modulation scheme is also proposed in which the ON period of square pulse (zero bits) is removed. Therefore, the data rate of DMOOK is increased because the duration of zero bit pulse is decreased. Similarly, the high bandwidth is utilized and BER performance deteriorates. All performance parameters are evaluated on Arduino based hardware VLC system. We conclude that the BER performance deteriorates by improving flickering performance and data rate of the VLC system.


Sign in / Sign up

Export Citation Format

Share Document