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oe1(光电查) - 科学论文

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出版时间
  • 2019
研究主题
  • FSO Communication System
  • Subcarrier Intensity Modulation
  • Atmospheric Turbulence
  • Bit Error Rate
  • Average Irradiance
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Galgotias College of Engineering and Technology
37 条数据
?? 中文（中国） ▾

  • [IEEE 2019 10th International Conference on Computing, Communication and Networking Technologies (ICCCNT) - Kanpur, India (2019.7.6-2019.7.8)] 2019 10th International Conference on Computing, Communication and Networking Technologies (ICCCNT) - Performance Analysis of Free Space Optical Communication Systems for High-Speed Trains

    摘要： Free space optics(FSO) can be used as an alternative the currently used wireless Radio communication systems to meet the increasing demands for the uninterrupted internet connection in High-Speed Trains(HSTs). FSO is less prone to interference, license-free and more secure as compared to Radio Frequency (RF) technology. The performance of the FSO system can be measured in terms of the average bit error rate(BER) and quality factor (Q-factor). In this paper, we have compared the NRZ and RZ modulation formats using a dual wavelength model at a bit rate of 10 Gbps to see which modulation format gives better Q-factor. The RZ modulation format is studied for a duty cycle of 33% and 67% and the comparison is made in terms of Q-factor. The system is also studied under different weather conditions in terms of Q-factor.

    关键词： HSTs(high speed trains),Q-factor,RZ,FSO,BER,NRZ

    更新于2025-09-16 10:30:52

  • Optical Fiber Communications (Principles and Applications) || Wireless Optics

    摘要： The wireless optics holds great potential for fixed wireless communications as well as for other wireless applications. In spite of all other technology developments, wireless optics has promised an economical alternative to last mile connection solution in the wireless domain. The concept of wireless optics was originally developed over few decades ago by the military. An optical wireless technology, also known as free space optics (FSO) technology, provides broadband data communication links between line-of-sight (point-to-point) locations.

    关键词： FSO,wireless optics,free space optics,broadband,line-of-sight

    更新于2025-09-12 10:27:22

  • [IEEE 2019 International Conference on Vision Towards Emerging Trends in Communication and Networking (ViTECoN) - Vellore, India (2019.3.30-2019.3.31)] 2019 International Conference on Vision Towards Emerging Trends in Communication and Networking (ViTECoN) - Modeling and Analysis of Hybrid SIM with L-PPM and MSK over Double Generalized Gamma Distribution in Free Space Optical Communication System

    摘要： In this paper, we use Double Generalized Gamma (GG) distribution in turbulence induced fading to model the communication channel under weak, moderate and strong turbulence condition. In order to further improve the performance of Free Space Optical (FSO) Communication system over Double GG distribution, we use Hybrid Subcarrier Intensity Modulation (SIM) with L-Pulse Position Modulation (L-PPM) and Minimum Shift Keying (MSK) and analyze its Bit Error Rate (BER) performance for average received irradiance between -12 dBm and 4 dBm. From the simulation results, we observe that BER decreases with decrease in average length of PPM symbol L under different turbulence conditions in FSO Communication system.

    关键词： FSO Communication System,Subcarrier Intensity Modulation,Atmospheric Turbulence,Bit Error Rate,Average Irradiance

    更新于2025-09-12 10:27:22

  • [IEEE 2019 IEEE/CIC International Conference on Communications in China (ICCC) - Changchun, China (2019.8.11-2019.8.13)] 2019 IEEE/CIC International Conference on Communications in China (ICCC) - Speeding up LDPC Decoder by Inter-Frame Pipeline for Wireless Laser Communications

    摘要： In order to meet the requirements of scenarios such as free space optical (FSO) communications using wireless laser, we need to improve the existing decoding structure of LDPC codes to achieve the goal of high throughput and high reliability. Aiming at solving a problem of idle time between layers in the column-serial layered decoder of LDPC codes, based on the dynamic multi-frame processing (DMFP) strategy we proposed a scheme called inter-frame pipeling (IFP) which can utilize the idle time for speeding up the decoder. Compared with the DMFP strategy the IFP has a doubled reduction of decoding delay. Taking a (4008,3507) LDPC code as an example, the ?eld-programmable gate array (FPGA) based implementation shows that the IFP scheme can increase throughput by at least 30%, approximately reaching to 2.5Gbps.

    关键词： dynamic multi-frame processing,free space optical (FSO) communications,Low-density parity-check (LDPC) codes,column-serial layered decoding

    更新于2025-09-12 10:27:22

  • A 640-Gbps, 15.2344-b/s/Hz full-duplex optical fiber/wireless single-channel coherent communication system using IQM-based DP-256-QAM and DSP techniques

    摘要： A full-duplex optical fiber/wireless single-channel coherent communication system is presented for high-speed data center interconnections. In-phase and quadrature modulator (IQM)-based dual polarization 256 quadrature amplitude modulation (DP-256-QAM) is implemented to achieve a maximum data rate of 640 Gbps with 40 Gbaud symbol rate for both the single-mode fiber (SMF) and free-space optics (FSO) links. Advanced digital signal processing (DSP) algorithms have been implemented at the receiver to compensate for signal impairments during propagation. The system with optical IQM and DSP algorithms can be fabricated in the form of cost-efficient integrated circuits and possess a potential spectral efficiency of 15.2344 b/s/Hz. A maximum transmission distance of 160 km and 4 km is achieved in simulation platform for the SMF and FSO links, respectively. The system performance is evaluated regarding laser linewidth requirements, optical signal-to-noise ratio tolerance, receiver sensitivity and launched optical power. This transceiver system shall be useful in high-speed long-haul communications, and the FSO system provides the same data rate to the remote areas, and last mile connections where laying of an optical fiber is not possible or cost is a major concern.

    关键词： FSO,Nyquist pulse,Full-duplex,DP-256-QAM,DSP,IQM

    更新于2025-09-12 10:27:22

  • Free Space Optical Communication (System Design, Modeling, Characterization and Dealing with Turbulence) || 5. Low power and compact RSM and neural-controller design for beam wandering mitigation with a horizontal-path propagating Gaussian-beam wave: focused beam case

    摘要： Beam wander on the detector plane is one of the main causes of major power loss which severely degrades the performance of Free Space Optical (FSO) links. Confronted with this big problem, designing a suitable controller to compensate beam wandering at a fast rate so as to increase beam stability becomes significant. This chapter presents an investigation of the performance of two types of controller designed for increasing the stability of the beam on the detector plane under dynamic disturbances. The first design is based on Taguchi’s method: Response Surface Model (RSM) controller while the second is the Artificial Neural Network (ANN) method (neural-controller). These controllers process the beam spot information and generate the necessary outputs to mitigate beam wandering, so as to perfectly couple the Power In the Bucket (PIB): receiver aperture, into the detector. Pipelined-parallel architecture for both controllers are proposed and developed in a Field Programmable Gate Array (FPGA). The implementation of these two candidate controllers is described in detail as installed at the receiver station. Evidence of the suitability and the effectiveness of the proposed controllers in terms of prediction exactness, prediction error, reduction of beam wander, response to impulse and effective scintillation index are provided through experimental results from the FSO link established for the horizontal range of 0.5 km at an altitude of 15.25 m.

    关键词： Artificial Neural Network (ANN),Field Programmable Gate Array (FPGA),beam wander,Free Space Optical (FSO) links,Response Surface Model (RSM)

    更新于2025-09-12 10:27:22

  • [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

  • Disaster management using free space optical communication system

    摘要： A novel method for disaster management using free space optical link is proposed in this paper. Free space optics recently gained great attention since it has advantages over RF communication such as high bandwidth, license free spectrum and highly secured transmission. Besides all these, FSO faces challenges during transmission due to atmospheric turbulence-induced fading. Diversity techniques are used in this paper to mitigate the fading effects. The capacity of multiple input multiple output (MIMO) free space optical (FSO) networks is increased using polarization division multiplexing (PDM). This paper proposed a novel method of MISO and MIMO-OFDM which uses both odd and even subcarriers to improve the transmission capacity. The separated OFDM subcarriers are combined using PDM, which supports two independent data channels on a single wavelength with orthogonal polarization states. The system performance is evaluated under various atmospheric turbulence conditions. This paper introduces a novel application of MIMO-FSO system during disaster scenario. The atmosphere is considered to be turbulent in nature, and Malaga model is used to characterize the channel. The closed-form expressions for MIMO-FSO are derived, and the graphs for the performance under different turbulent conditions are plotted.

    关键词： Malaga channel model,Optical orthogonal frequency division multiplexing (OFDM),Ergodic capacity,Multiple input multiple output (MISO),Polarization division multiplexing (PDM),Free space optical networks (FSO)

    更新于2025-09-11 14:15:04

  • Efficient Optical Alignment Technique for Compact 100 and 400 GbE TOSAs with Integrated Multiplexing with Free Space Optics

    摘要： An efficient and low-cost optical alignment technique is for the first time established for compact transmitter optical sub-assemblies (TOSAs) with an integrated multiplexer based on free space optics (FSO) for 100 and 400 Gbps Ethernet (GbE) applications. A compact FSO system for the 100 GbE TOSA is fabricated in a compact package 6.5 mm × 15.1 mm × 5.6 mm in size to confirm the validity of the technique. It is demonstrated by experiment that the optimum optical alignment condition can successfully be figured out by this technique without any expensive equipment, which has been a significant issue for TOSAs with integrated FSO systems, confirming the validity of the technique. Further, Monte Carlo simulations show that the optical output power distribution across the lanes is compatible with the 100 GbE LR4 specification, indicating the suitability of the proposed low-cost alignment technique. It is also shown that the acceptable long-term power variation required for reliability is predicted owing to the relaxation of the positional tolerance of the collimator lenses, which is obtained by the proposed technique. Finally the feasibility of the technique is discussed for 400 GbE TOSAs with eight-lane optical systems.

    关键词： transmitter optical sub-assembly (TOSA),laser diode (LD),100 and 400 Gbps Ethernet (GbE),Free space optics (FSO),hybrid integration

    更新于2025-09-10 09:29:36

  • [IEEE 2018 International Conference on Information and Communications Technology (ICOIACT) - Yogyakarta (2018.3.6-2018.3.7)] 2018 International Conference on Information and Communications Technology (ICOIACT) - Dynamical characteristics of the FSO transmission capacity in the presence of Rician turbulence

    摘要： In this paper temporal behavior of the free-space optics (FSO) channel capacity under the influence of Rician turbulence is considered. Expressions for the Cumulative Distribution Function (CDF), Probability Density Function (PDF), and the Level Crossing Rate (LCR) of the transmitted FSO signal exposed to Rician turbulence are derived, and numerical results graphically presented.

    关键词： FSO,channel capacity,Rician turbulence,PDF,LCR

    更新于2025-09-10 09:29:36