Results 31 to 40 of about 3,274,533 (303)

On the Performance of Coherent OFDM Systems in Free-Space Optical Communications

open access: yesIEEE Photonics Journal, 2015
This paper presents a new model of a coherent orthogonal frequency division multiplexing free space optical communication (OFDM-FSO) system that can be tuned with the virtual local oscillator, under the Gamma-Gamma atmospheric turbulence channel, not ...
Yi Wang, Deli Wang, Jing Ma
doaj   +1 more source

Doppler Wind Lidar From UV to NIR: A Review With Case Study Examples

open access: yesFrontiers in Remote Sensing, 2022
Doppler wind lidar (DWL) uses the optical Doppler effect to measure atmospheric wind speed with high spatial-temporal resolution and long detection range and has been widely applied in scientific research and engineering applications.
Mingjia Shangguan   +7 more
doaj   +1 more source

Airborne direct-detection and coherent wind lidar measurements along the east coast of Greenland in 2009 supporting ESA’s Aeolus mission [PDF]

open access: yes, 2011
The Aeolus mission of the European Space Agency (ESA) will send the first wind lidar to space to fulfill the utmost need for global wind profile observations.
Witschas, Benjamin   +11 more
core   +1 more source

Coherent Radio-Over-Fiber and Millimeter-Wave Radio Seamless Transmission System for Resilient Access Networks

open access: yesIEEE Photonics Journal, 2012
We propose a millimeter-wave (MMW) coherent radio-over-fiber (RoF) transmission system for application to an access network with a direct broadband last-mile wireless connection to an optical fiber network.
A. Kanno   +7 more
doaj   +1 more source

Digital self-coherent detection

open access: yesOptics Express, 2008
We review recent progresses on digital self-coherent detection of differential phase-shift keyed (DPSK) signal using orthogonal differential direct detection followed by high-speed analog-to-digital conversion and digital signal processing (DSP). Techniques such as data-aided multisymbol phase estimation for receiver sensitivity enhancement, unified ...
Xiang, Liu   +2 more
openaire   +2 more sources

Free-Space Optical Communication Based on Mode Diversity Reception Using a Nonmode Selective Photonic Lantern and Equal Gain Combining

open access: yesIEEE Photonics Journal, 2023
This paper experimentally investigates the perform-ance of free-space optical (FSO) communication based on mode diversity reception (MDR) using nonmode selective photonic lantern (NSPL) and equal gain combining (EGC).
Feng Wang   +3 more
doaj   +1 more source

Portable Pulsed Coherent Lidar for Noncooperation Targets at the Few-Photon Level

open access: yesSensors, 2021
The decoherence in coherent lidar becomes serious with the increase in distance. A small laser spot can suppress the decoherence of the echo light from noncooperation targets. However, it is very difficult to keep a small light spot over a long distance.
Chengkai Pang   +3 more
doaj   +1 more source

Recent Advances in Coherent Optical Communications for Short-Reach: Phase Retrieval Methods

open access: yesPhotonics, 2023
Short-reach transmission systems traditionally utilize intensity modulation (IM) at the transmitter and direct detection (DD) at the receiver due to their cost-effectiveness, small footprint, and low power consumption.
Abdullah S. Karar   +4 more
doaj   +1 more source

Capturing the amplitude and phase profile of the vortex beam based on coherent detection

open access: yesFrontiers in Physics, 2022
In this study, we propose a scheme to capture the amplitude and phase profile of the orbital angular momentum (OAM) beam based on coherent detection. In the scheme, the OAM beam to be measured is interfered with a local plain wave which is prepared at ...
Shengmei Zhao   +3 more
doaj   +1 more source

Coherent and Noncoherent Detection CPFSK

open access: yesIEEE Transactions on Communications, 1974
Continuous phase frequency shift keying (CPFSK) is potentially an attractive modulation scheme for use on channels whose performance is limited by thermal noise. In this paper results for the performance available with CPFSK are given for coherent detection and noncoherent detection with arbitrary modulation indices and arbitrary observation intervals.
Osborne, William P., Luntz, Michael B.
openaire   +2 more sources

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