- 标题
- 摘要
- 关键词
- 实验方案
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Performance evaluation for polarization shift keying modulation in atmospheric turbulence channel
摘要： The exponentiated Weibull (EW) distribution is adopted for all turbulence strengths when aperture averaging technology is applied. Firstly, the closed expression of the average bit error rate (BER) of a free space optical (FSO) system using polarization shift keying (POLSK) modulation under EW atmosphere turbulence model is derived. Then the effects of aperture averaging under different turbulence conditions described by the EW distribution are numerically studied with computer simulation, and the average BER of POLSK modulated system is compared with that of an on-off-keying (OOK) system. Numerical results show the effects of aperture averaging on the average BER under different turbulence strengths. The POLSK modulated FSO systems can offer better BER performance compared to OOK scheme.
关键词： average bit error rate,exponentiated Weibull distribution(EW),Polarization shift keying modulation(POLSK),aperture averaging,on-off-keying (OOK)
更新于2025-09-12 10:27:22
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Optical Fiber and Wireless Communications || Fundamental Analysis for Visible Light Communication with Input‐Dependent Noise
摘要： Recently, visible light communication (VLC) has drawn much attention. In literature, the noise in VLC is often assumed to be independent of the input signal. This assumption neglects a fundamental issue of VLC: due to the random nature of photon emission in the lighting source, the strength of the noise depends on the signal itself. Therefore, the input-dependent noise in VLC should be considered. Given this, the fundamental analysis for the VLC with input-dependent noise is presented in this chapter. Based on the information theory, the theoretical expression of the mutual information is derived. However, the expression of the mutual information is not in a closed form. Furthermore, the lower bound of the mutual information is derived in a closed form. Moreover, the theoretical expression of the bit error rate is also derived. Numerical results verify the accuracy of the derived theoretical expressions in this chapter.
关键词： bit error rate,input-dependent noise,visible light communication,mutual information
更新于2025-09-12 10:27:22
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Free Space Optical Communication (System Design, Modeling, Characterization and Dealing with Turbulence) || 6. Quality metrics and reliability analysis of ground-to-ground free space laser communication in different weather conditions together with beam steering system
摘要： Over the past two decades Free Space Optical Communication (FSOC) has become more and more interesting as an adjunct or alternative to Radio Frequency (RF) communication. Optical wave propagation in an FSOC channel is severely affected by turbulent atmospheric parameters and they lead to the degradation of the data transmission quality and reliability. Among the various atmospheric effects, beam wandering is the main cause for major power loss and cannot be solved without incorporation of a Beam Wandering Compensation (BWC) control system. Therefore, a closed form treatment describing beam wandering effect mitigation is required. Simplex FSOC data transmission (data rate is 155 Mbps) transmitter-receiver experimental setups are established for the data link range of 0.5 km at an altitude of 15.25 m at the college campus. A near IR 850 nm optical source is used for data transmission. The more accurate values of atmospheric attenuation (Atten) and turbulence strength (C2n) are obtained using the new models developed according to local weather data. The transmittance of the FSOC channel is calculated using the estimated atmospheric attenuation. The methods of measuring the Q-factor and Bit Error Rate (BER) by postprocessing the received signal are described and used to validate the performance of the FSOC system. The improvements on received signal strength and centroid stability by incorporating the BWC control system are analyzed with various communication key parameters in the very weak to very strong atmospheric turbulence conditions. The average BER at a value of 9.82 ? 10?9 is maintained with the Q-factor value of ≈ 6 in almost all atmospheric turbulence conditions with compensating beam wandering effects, i.e. pointing error losses. Evidence of the suitability and effectiveness of the developed controller in terms of received power (Pr), transmittance (T), eye diagram, Q-factor, Signal to Noise Ratio (SNR), BER, link margin and decoding decision threshold values are comprehensively analyzed through experimental results and reported in this chapter.
关键词： atmospheric turbulence,Beam Wandering Compensation (BWC),Q-factor,Signal to Noise Ratio (SNR),Bit Error Rate (BER),Free Space Optical Communication (FSOC)
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall) - Honolulu, HI, USA (2019.9.22-2019.9.25)] 2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall) - Performance of Free Space Optical Communication System under Jamming Attack and Its Mitigation over Non-Gaussian Noise Channel
摘要： In free space optical (FSO) communication, jamming can cause inaccuracy in the received information. In this paper, we investigate the impact of jamming over atmospheric turbulence (AT) fading channels. To describe the AT, negative exponential fading channel models are considered. The effect of jamming is studied over a single-input single-output (SISO) FSO link. We introduce a theoretical framework to acquire a closed-form expression of the average bit error rate (ABER) under jamming–leading to an additive non-Gaussian noise channel. It is observed by thorough analysis that a 2 × 1 FSO system performs better than SISO FSO system in presence of jamming signal. It is realized that under jamming the performance of FSO link is dependent on different AT conditions. Furthermore, increasing number of transmit apertures allows FSO system to significantly overcome the effect of jamming, in order to obtain an improved ABER.
关键词： Additive non-Gaussian noise,exponential fading,signal-to-jamming ratio (SJR),bit error rate (BER),free space optical (FSO) communication,jamming,Gamma-Gamma fading
更新于2025-09-12 10:27:22
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Novel OCDMA Schemes in Free Space Optical Communication Networks: Performance Evaluation and Comparative Analysis
摘要： Free space optical (FSO) communication based networks are constrained due to the atmospheric turbulence, which limits the achievable data rates. Employing code-division multiple-access (CDMA) with FSO system can provide a feasible solution for seamlessly multiplexing a large number of users. The CDMA data can be with negative polarity, and thus for intensity modulation over optical links, usually a suitable DC bias is added to the CDMA data. We refer to this scheme as DC biased Optical CDMA (DC-OCDMA). It, however, also requires a higher bit energy. We propose two novel OCDMA (OCDMA) schemes, viz., dual wavelength OCDMA (DW-OCDMA) and wavelength diversity OCDMA (WD-OCDMA) to improve the Eb/No penalty incurred due to DC-OCDMA scheme. The first scheme utilizes two wavelengths for separating positive and negative data of the CDMA, and the second scheme exploits diversity. We compare the performance of the proposed schemes with the DC-OCDMA technique in different turbulence regimes and show that the WD-OCDMA scheme outperforms the DC-OCDMA scheme in all turbulence regimes whereas DW-OCDMA scheme outperforms DC-OCDMA scheme in moderate and low turbulence regimes. Moreover, out of the two proposed techniques, the WD-OCDMA gives higher Eb/No gain than the DW-OCDMA scheme in moderate and high turbulence regimes whereas DW-OCDMA scheme outperforms the WD-OCDMA scheme in low turbulence regime.
关键词： bit error rate,optical code division multiple access,free space optical communication
更新于2025-09-12 10:27:22
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Performance analysis of 349-element adaptive optics unit for a coherent free space optical communication system
摘要： As a continuation of our previous work [Optics Express.25, 15229(2017)] in which we have verified the performance of a coherent free space optical communication (FSOC) system with a 97-element adaptive optics (AO) system, in this paper, we evaluated the performance improvement of the coherent FSOC system using a large-scale high-speed AO system with a 349-element continuous surface deformable mirror. The mixing efficiency (ME) and bit-error-rate (BER) under different Greenwood frequency (GF) were calculated as the performance metric of coherent FSOC system. The performance of FSOC system using such a large-scale AO system was quantitatively verified for the first time. The obtained results showed that the performance was obviously improved when a larger-scale high-speed AO system is employed in coherent FSOC system. This analysis result provides a performance verification for large-scale high-speed AO systems used in FSOC system which is beneficial for coherent FSOC system parameters design.
关键词： bit-error-rate,adaptive optics,free space optical communication,coherent detection,mixing efficiency
更新于2025-09-11 14:15:04
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Fiber Optic and Atmospheric Optical Communication || Transmission of Information Data in Optical Channels: Atmospheric and Fiber Optics
摘要： The chapter discusses the transmission of information data in optical channels, focusing on atmospheric and fiber optics. It highlights the challenges posed by atmospheric effects on wave propagation, including attenuation, optical signal amplitude, and phase scintillations caused by atmospheric turbulence. The chapter also explores the impact of these phenomena on the data stream parameters, such as bit error rate (BER) and signal-to-noise ratio (SNR), and proposes methods to mitigate these effects to achieve high performance in optical communication links.
关键词： atmospheric turbulence,bit error rate,optical communication,spectral efficiency,signal-to-noise ratio,scintillation,fading,Ricean K-factor,fiber optics,multipath channel
更新于2025-09-11 14:15:04
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[IEEE 2018 International Conference on Communication and Signal Processing (ICCSP) - Chennai, India (2018.4.3-2018.4.5)] 2018 International Conference on Communication and Signal Processing (ICCSP) - Design and Performance Evaluation of Bidirectional WDM-PON Using FTTH Architecture
摘要： Optical fiber cable has been presented as a solution to high bandwidth demand. A bidirectional WDM-PON (wavelength division multiplexed-passive optical network) with FTTx (fiber to the x, where x=home, hospital, business, school, mall, etc.) model has been presented with EDFA, WDM mux-demux splitter and APD photo detector for long haul transmission system and as a solution to last mile problem. The proposed model has been designed for 3 Gbps non-return to zero (NRZ) transmission system over 30 km long bidirectional optical fiber. The proposed model is applied on Coarse Wavelength Division Multiplexing (CWDM). Further, it has also been compared with the existing reported work on the basis of quality factor, BER and eye diagrams. The proposed model enhances the performance in terms of bit error rate and quality factor at the downstream and upstream end of the systems.
关键词： FTTH,Q-factor,eye diagram,bit error rate,WDM-PON
更新于2025-09-10 09:29:36
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Enhanced inter-lighting interference cancellation using power control to improve the performance of indoor visible light communication systems
摘要： In this study, the authors propose an enhanced inter-lighting interference cancellation (E-ILIC) in order to distinguish the received signals, combating the equal powers at the receiver side and hence improve the average bit error rate (BER) performance of a multiple-input-single-output visible light communication (VLC) system. VLC is a promising technology for indoor environments, it makes use of the light emitting diode (LED) lamps already installed to transmit information through the visible light. When several LEDs transmit simultaneously different data to increase the transmission capacity, it leads to co-channel interference that degrades the BER performance. For this reason, they investigate E-ILIC that is a combination of ILIC with closed loop power control to receive the signals with different power level. It employs power allocation at the transmitter when the received power ratio does not comply with a specific threshold. Furthermore, it reduces significantly the interference between adjacent LED lamps, obtaining useful information at the receiver side. Through computer simulations, E-ILIC achieves the best average BER performance in any user position when the assignment of the power weights is correctly performed on the LEDs.
关键词： MISO,bit error rate,co-channel interference,CCI,BER,visible light communication,inter-lighting interference cancellation,multiple-input-single-output,ILIC,VLC,power control
更新于2025-09-10 09:29:36
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[IEEE 2017 IEEE International WIE Conference on Electrical and Computer Engineering (WIECON-ECE) - Dehradun (2017.12.18-2017.12.19)] 2017 IEEE International WIE Conference on Electrical and Computer Engineering (WIECON-ECE) - Hybrid Beamforming Utilization Perspective for Future 5G Millimeter Wave Communication
摘要： This paper presents hybrid beamforming perspective which will play a vital role in upcoming 5G millimeter wave communication systems. Windowing techniques are implemented in this paper which helps in suppression of sidelobes of the beam. Analysis of directivity with respect to number of antenna elements with combination of windowing techniques has also been observed in this paper. Thus in this paper analysis for future technology has been provided which will act as building blocks for millimeter wave communications.
关键词： SLL (Side Lobe Level),BER (Bit Error Rate),MRA (Maximum Response Angle),MLW (Main Lobe Width),ULA(Uniform Linear Array)
更新于2025-09-09 09:28:46