- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE GLOBECOM 2019 - 2019 IEEE Global Communications Conference - Waikoloa, HI, USA (2019.12.9-2019.12.13)] 2019 IEEE Global Communications Conference (GLOBECOM) - Intelligent Reflecting Surfaces for Free Space Optical Communications
摘要： In this paper, we investigate the use of intelligent reflecting surfaces (IRSs) (i.e., smart mirrors) to relax the line-of-sight requirement of free space optical (FSO) systems. We characterize the impact of the physical parameters of the IRS, such as its size, position, and orientation, on the quality of the end-to-end FSO channel. In addition, we develop a statistical channel model for the geometric and the misalignment losses which accounts for the random movements of the IRS, transmitter, and receiver due to building sway. This model can be used for performance analysis of IRS-based FSO systems. Our analytical results shows that depending on the angle between the beam direction and the IRS plane, building sway for the IRS has either a smaller or larger impact on the quality of the end-to-end FSO channel than building sway for the transmitter and receiver. Furthermore, our simulation results validate the accuracy of the developed channel model and offer insight for system design.
关键词： Smart mirrors,Channel model,Free space optical communications,Intelligent reflecting surfaces,Building sway
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE International Electron Devices Meeting (IEDM) - San Francisco, CA, USA (2019.12.7-2019.12.11)] 2019 IEEE International Electron Devices Meeting (IEDM) - Integrated DFB Laser Diode and High-efficiency Mach-Zehnder Modulator using Membrane III-V Semiconductors on Si Photonics Platform
摘要： This paper presents a 3-D statistical channel impulse response (IR) model for urban line of sight (LOS) and non-LOS channels developed from 28- and 73-GHz ultrawide-band propagation measurements in New York City, useful in the design of 5G wireless systems that will operate in both the ultra-high frequency/microwave and millimeter-wave (mmWave) spectrum to increase channel capacities. A 3GPP-like stochastic IR channel model is developed from measured power delay profiles, angle of departure, and angle of arrival power spectra. The extracted statistics are used to implement a channel model and simulator capable of generating 3-D mmWave temporal and spatial channel parameters for arbitrary mmWave carrier frequency, signal bandwidth, and antenna beamwidth. The model presented here faithfully reproduces realistic IRs of measured urban channels, supporting air interface design of mmWave transceivers, filters, and multi-element antenna arrays.
关键词： 28 GHz,multipath,time cluster spatial lobe (TCSL),spatial lobe (SL),statistical simulator,5G,spatial channel model (SCM),73 GHz,Channel model,millimeter-wave (mmWave) propagation,3-D ray-tracing,time cluster (TC),impulse response (IR)
更新于2025-09-23 15:19:57
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An improved color image defogging algorithm using dark channel model and enhancing saturation
摘要： Fog is an atmospheric phenomenon that signi?cantly degrades the visibility of outdoor scenes. It is di?cult to lock in and track o? criminals clarity in the high-de?nition surveillance hazy image and driverless. In our research, we develop dark channel model, re-re?ned transmission map by transferring coe?cient. Compared with other defogging methods based on single color image prior, our method is a e?ectiveness of the proposed defogging algorithm, enhanced the saturation of defogging image and a higher quality depth map can be obtained of fog removal. In this way, a clear hazy image is obtained while maintaining the fog removing quality. Moreover, a good quality defogging image can be validated of fog removal by PSNR and MSE.
关键词： Fog removal,Saturation,Hazy image,Dark channel model
更新于2025-09-23 15:19:57
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[IEEE 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Shenzhen, China (2019.11.25-2019.11.27)] 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - High color rendering index white LEDs fabricated using InP/ZnS green-emitting quantum dots and InP/ZnSe/ZnS red-emitting quantum dots
摘要： This paper presents a 3-D statistical channel impulse response (IR) model for urban line of sight (LOS) and non-LOS channels developed from 28- and 73-GHz ultrawideband propagation measurements in New York City, useful in the design of 5G wireless systems that will operate in both the ultra-high frequency/microwave and millimeter-wave (mmWave) spectrum to increase channel capacities. A 3GPP-like stochastic IR channel model is developed from measured power delay profiles, angle of departure, and angle of arrival power spectra. The extracted statistics are used to implement a channel model and simulator capable of generating 3-D mmWave temporal and spatial channel parameters for arbitrary mmWave carrier frequency, signal bandwidth, and antenna beamwidth. The model presented here faithfully reproduces realistic IRs of measured urban channels, supporting air interface design of mmWave transceivers, filters, and multi-element antenna arrays.
关键词： 5G,28 GHz,3-D ray-tracing,multipath,time cluster (TC),spatial lobe (SL),millimeter-wave (mmWave) propagation,statistical simulator,spatial channel model (SCM),time cluster spatial lobe (TCSL),Channel model,impulse response (IR),73 GHz
更新于2025-09-16 10:30:52
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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) - Study on the Effect of System Parameters on Physical-Layer Security of Optical CDMA Systems
摘要： Optical CDMA (OCMDA) technology directly encrypts optical transmission links at the physical layer, which can improve the security of communication system against fibre-optic eavesdropping attacks. System parameters will affect the performances of OCDMA systems, based on the wiretap channel model of OCDMA systems, “secrecy capacity” is employed as an indicator to estimate the effects of system parameters (the type of code words, the length of code words) on the security of the systems. Simulation results demonstrate that system parameters play an important role and choosing the code words with better cross-correlation characteristics can improve the security of OCDMA systems.
关键词： Wiretap Channel Model,Secrecy Capacity,System Parameters,Physical-Layer Security,Optical CDMA (OCDMA)
更新于2025-09-16 10:30:52
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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
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Deployment Issues and Performance Study in a Relay-Assisted Indoor Visible Light Communication System
摘要： This paper investigates the deployment issues and analyzes the performance of a relay-assisted indoor visible light communications (VLC) system with dc-biased optical orthogonal frequency division modulation (DCO-OFDM). The study considers two light sources in an office environment. One light source works as the information source and is located at the ceiling while the other one works as the relay terminal, which usually is a desk light or a floor light. We analyze the general blockage in a room, discuss the path loss of the VLC channel, and compare received signal power from a line of sight (LOS) link and a non-LOS link. The constraints on the relay height in order to achieve LOS connection are investigated. Simplified optimal power allocation under illumination and blockage constraints is proposed. Bit error rate performance is analyzed and the required signal power is derived for the relay-assisted DCO-OFDM VLC system. The study shows that in a relay-assisted VLC system, the blockage of source to destination link has trivial influence on the overall system performance if relays are properly deployed.
关键词： indoor,visible light communications (VLC),dc-biased optical orthogonal frequency division modulation (DCO-OFDM),relay,Channel model,power allocation
更新于2025-09-09 09:28:46
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Path loss model modification for various gains and directions of antennas
摘要： Emerging telecommunication technologies like 5G, green communications, and massive MIMO contribute to the use of directional antennas and beamforming. For this reason, modern propagation models consider directional antennas with different beam widths, gains and radiation pattern directions. Most of the available propagation models are based on omnidirectional or isotropic antennas. A proposition to solve this problem is an empirical path loss model that considers the different types of antennas. This model assumes that the transmitting and receiving antenna beams are directing each other. In this paper, we propose modifying this model by determining attenuation for any direction of the antenna patterns. For this aim, the multi-elliptic channel model is used.
关键词： gain,non-line-of-sight conditions,directional antenna,multipath propagation,multi-elliptical channel model,antenna pattern,channel modeling,path loss model
更新于2025-09-04 15:30:14