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Simultaneous optical signal to noise ratio and symbol rate estimation with blind chromatic dispersion compensation for auxiliary amplitude modulation optical signals

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Chinese Optics Letters 2016年第9期14卷 15-19页

作者：魏俊宇覃江毅黄芝平郭晓俊 College of Mechatronics Engineering and Automation National University of Defense Technology

Based on the peak to valley ratio（PTVR） of the average magnitude difference function（AMDF）, we present a novel optical signal to noise ratio（OSNR） and symbol rate（SR） estimation method for commonly used auxiliary amplitude modulations（AAMs）. Moreover, it is demonstrated that the influence of chromatic dispersion（CD）on the method can be mitigated by maximizing the PTVR of the AMDF with additional tunable dispersion compensators. The results of simulations show that the OSNR estimation error can be kept within 0.8 dB in the wide OSNR range of（12, 32） dB, while the SR estimation error is below 0.079% for four widely used10 Gsymbol/s AAM signals.

关键词： Amplitude modulation Blind equalization Chromatic dispersion Estimation Modulation signal to noise ratio

Numerical analysis of Raman amplification and optical signal-to-noise ratio in a photonic crystal fiber

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Chinese Optics Letters 2006年第8期4卷 446-448页

作者：尚韬陈建平李新碗周俊鹤 The State Key Laboratory on Fiber-Optic Local Area Communication Networks and Advanced Optical Communication Systems Shanghai Jiao Tong University

A numerical design on the triangular photonic crystal fiber （PCF） based backward multi-pump Raman amplifier is presented. It is demonstrated that high flat Raman gain can be reached based on PCF. Influences of different geometric parameters and germanium doping concentrations on the Raman net gain, amplified spontaneous emission （ASE） noise and double Rayleigh backscattering （DRBS） of the signal have been analyzed. For optimizing crystal fiber Raman amplifier （FRA）, there is tradeoff between the geometric parameter and germanium doping concentration of triangular PCF. The results show that PCF is an appropriate candidate for high gain Raman amplifiers.

关键词： Backscattering Doping (additives) Germanium Numerical analysis signal to noise ratio Spontaneous emission

Influence of the nonlinear propagation effect on the optical signal-to-noise ratio of 400G optical fiber communication systems

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Chinese Optics Letters 2017年第3期15卷 78-82页

作者：秦华强肖晓晟 State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

The influence of the nonlinear propagation effect on three 400 Gb/s/ch （400G） optical fiber communication systems with typical modulation formats, dual-carrier 16-quadrature amplitude modulation （16QAM）, single-carrier 16QAM （single-16QAM）, and four-carrier quadrature phase-shift keying, are investigated. The received optical signal-to-noise ratio （OSNR）, affected by the nonlinear interference noise together with the amplified spontaneous emission noise, are compared with three 400G systems and a standard 100 Gb/s/ch system by numerical simulations. Both single channel and multichannel cases are considered. Single-16QAM is found to have the best OSNR among those modulation formats.

关键词： Modulation Nonlinear optics Optical communication Optical fibers Optical signal processing Phase shift Phase shift keying Quadrature amplitude modulation Quadrature phase shift keying signal to noise ratio

signal recovery method based on co-prime array

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Journal of Systems Engineering and Electronics 2017年第2期28卷 224-234页

作者： Shuang Qiu Weixing Sheng Xiaofeng Ma Yubing Han Renli Zhang School of Electronic and Optical Engineering Nanjing University of Science and TechnologyNanjing 210094China

A signal waveform recovery method based on the co-prime array is investigated to extract the waveform of the desired signal from spatial interferences in narrowband scenarios. The direction of arrivals (DOAs) of the desired signal and interference signals are estimated with the compressive sensing approach based on angle grids, and the signal power together with the noise power are estimated. Thereafter, a modified steepest descent (SD) method is derived to recover the waveform of the desired signal and interferences utilizing the estimated power and directions. The recovered waveform of the desired signal is the output of the proposed method. The situation in which the signals are not on the predefined angle grids is also considered. The DOAs estimated via the predefined angle grids are corrected based on the maximum likelihood (ML) angle estimation. Compared to the existing beamforming methods on co-prime array, the proposed method can obtain the waveform of the desired signal. Simulation results demonstrate that the proposed method can achieve good performance in signal waveform recovery and output signal to noise ratio. © 2017 Beijing Institute of Aerospace Information.

关键词： Compressed sensing Maximum likelihood Maximum likelihood estimation Recovery signal reconstruction signal to noise ratio

Performance Analysis of Spatial Modulation Aided UAV Communication Systems in Cooperative Relay Networks

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Chinese Journal of Electronics 2024年第6期33卷 1492-1503页

作者： Xiangbin YU Mingfeng XIE Ning LI Cuimin PAN College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics State Key Laboratory of Millimeter Waves Southeast University

In this paper, by introducing the spatial modulation(SM) scheme into the unmanned aerial vehicle(UAV) relaying system, an SM-aided UAV(SM-UAV) cooperative relay network is presented. The performance of the SM-UAV relay network is investigated over Nakagami-m fading channels, where the UAV remains stationary over a given area. According to the performance analysis, using the amplify-and-forward(AF) protocol, the effective signal-to-noise ratio(SNR) and the corresponding probability density function and moment generating function are,respectively, derived. With these results, the average bit error rate(BER) is further deduced, and resultant approximate closed-form expression is achieved. Based on the approximate BER, we derive the asymptotic BER to characterize the error performance of the system at high SNR. With this asymptotic BER, the diversity gain of the system is derived, and the resulting diversity order is attained. Simulation results illustrate the effectiveness of the performance analysis. Namely, approximate BER has the value close to the simulated one, and asymptotic BER can match the corresponding simulation well at high SNR. Thus, the BER performance of the system can be effectively assessed in theory, and conventional simulation will be avoided. Besides, the impacts of the antenna number, modulation order,fading parameter, and UAV position on the system performance are also analyzed. The results indicate that the BER performance is increased with the increases of Nakagami parameter m and/or receive antenna and/or the decrease of modulation order.

关键词： Fading channels System performance Bit error rate Modulation Receiving antennas Relay networks Diversity methods Autonomous aerial vehicles Performance analysis signal to noise ratio

Influence of variables in deep drawing of AA 6061 sheet

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Transactions of Nonferrous Metals Society of China 2010年第10期20卷 1856-1862页

作者： S.RAJU G.GANESAN R.KARTHIKEYAN Department of Manufacturing Engineering Annamalai University Department of Mechanical Engineering

Deep drawing is one of the most important processes for forming sheet metal *** is widely used for mass production of cup shapes in automobile,aerospace and packaging *** drawing,besides its importance as forming process,also serves as a basic test for the sheet metal *** effect of equipment and tooling parameters results in complex deformation *** of thickness variation in the formed part may cause stress concentration and may lead to acceleration of *** TAGUCHI's signal-to-noise ratio,it is determined that the die shoulder radius has major influence followed by blank holder force and punch nose radius on the thickness distribution of the deep drawn cup of AA 6061 *** optimum levels of the above three factors,for the most even wall thickness distribution,are found to be punch nose radius of 3 mm,die shoulder radius of 8 mm and blank holder force of 4 kN.

关键词： deep drawing aluminium alloy thickness distribution signal to noise ratio

Investigations of range accuracy for long-range three-dimensional active imaging

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Chinese Optics Letters 2011年第6期9卷 48-50页

作者：张秀达严惠民周琴 State Key Laboratory of Modern Optical Instrument National Engineering Research Center for Optical Instrument Optical Engineering Department Zhejiang University

Distance resolutions and noises are analyzed experimentally for long-range three-dimensional （3D） active imaging systems that have signal-to-noise ratios （SNRs） more optimal than 30：1. Findings indicate that the photon shot noise primarily determines the SNR. However, the active imaging method, which has a relatively low SNR, generates a relatively high distance resolution. To explain this phenomenon, a theory in which the distance resolution of 3D active imaging systems is determined by both the photon shot noise and the subinterval width is developed. Theoretical and experimental results differ by less than 4%.

关键词： Imaging systems Photons Shot noise signal to noise ratio

Stochastic Resonance in a Bistable Sawtooth Potential Driven by COrrelated Multiplicative and Additive noise

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Chinese Physics Letters 2002年第10期19卷 1416-1419页

作者：王俊曹力等 StateKeyLaboratoryofLaserTechnology HuazhongUniversityofScienceandTechnologyWuhan430074 DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074

We present an analytical investigation of the signal-to-noise ratio (SNR) by studying the bistable sawtooth system driven by correlated Gaussian white noise. The analytic expression of the SNR is obtained. We detect some novel results, as follows. (1) Stochastic resonance (SR) always occurs in the SNR-Q (the multiplicative noise intensity) curve for the whole range of correlation coefficients. (2) There is not only resonance but also suppression and monotony in the dependence of SNR upon the additive noise intensity. (3) There are two extrema (one is minimum, the other maximum) in the SNR-b (the barrier height) curve for different multiplicative noise intensities

关键词： signal to noise ratio

Analysis of saturation signal correction of the troposphere lidar

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Chinese Optics Letters 2009年第11期7卷 1051-1054页

作者：刘智深李志刚刘秉义李荣忠 Key Laboratory of Ocean Remote Sensing Ministry of Education of ChinaOcean University of China

Usually, lidar detection systems are optimized for the measurement of the low intensity signal using the photon counting technique, but this approach results in the nonlinear signal response for the higher intensity signal. The problem is successfully solved by the combination of analog-to-digital （AD） and photon- counting （PC） detection. The optimized processing procedure of the signal combination of AD and PC is described, and the corrected result is analyzed and compared with the results by the dealt-time correction method. In this way, the accuracy of wind and aerosol measurement in the nonlinear range is improved. In addition, the signal-to-noise ratios （SNRs） of the two detection methods of AD and PC are compared in the overall dynamic range of signal for the performance analysis.

关键词： Atmospherics Optical radar signal to noise ratio