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Liu J.,Xidian University | Zhao H.-Y.,Xidian University | Liu W.,Wuhan Electronic Information Institute | Li H.,Stevens Institute of Technology | Liu H.,Xidian University
Signal Processing | Year: 2017

This paper examines a target detection problem in colored Gaussian disturbance with an unknown covariance matrix. In many classic adaptive detectors, the covariance estimator is formed by using only the training data. This necessitates calculating a new covariance estimator for each cell under test (CUT) during the cell-by-cell target search process. We consider herein an alternative approach that forms the covariance matrix estimate by using both test and training data for detection in homogeneous environments. This approach is computationally much more efficient since the covariance matrix estimator is computed only once and can be applied for target detection at each CUT. Using this estimator, we propose a new detector with two tunable parameters, which includes several existing detectors as special cases. Closed-form expressions for the probabilities of false alarm and detection are derived in the matched and mismatched cases for both non-fluctuating and fluctuating target models. Simulation results reveal that the rejection capability of mismatched signals of the proposed detector can be flexibly controlled by adjusting its tunable parameters. In particular, the proposed detector can achieve the same detection performance as the generalized likelihood ratio test (GLRT) detector derived by Kelly, but has a much lower computational burden. © 2017 Elsevier B.V.

Luo X.,Wuhan Electronic Information Institute | Yu L.,Wuhan Electronic Information Institute | Zhang D.,Wuhan Electronic Information Institute | Wang A.,Wuhan Electronic Information Institute
ICOCN 2016 - 2016 15th International Conference on Optical Communications and Networks | Year: 2016

We present a novel photonic approach based on heterodyne between a multiple-dispersed optical pulse and a continuous optical signal to generate tunable linearly chirped microwave waveform (LCMW) with large time-bandwidth product (TBWP). The carrier frequency of the generated waveform can be changed by tuning the frequency of continuous optical wave outputted from the tunable laser source (TLS),while the TBWP of the LCMW can be changed by optically pumping the linearly chirped fiber Bragg grating (LCFBG) in the dispersive loop with different pumping powers. An extremely large equivalent dispersion will be obtained because of the dispersive loop used in the system, which leads to the generation of LCMW with long temporal duration. The capability of the presented method is verified via numeric simulation. © 2016 IEEE.

Wang H.,Wuhan Electronic Information Institute | He M.-H.,Wuhan Electronic Information Institute | Xu J.,Wuhan Electronic Information Institute | Xu D.,Wuhan Electronic Information Institute
Communications in Computer and Information Science | Year: 2012

The recognition of radar emitter signals (RES) is one of the key technologies in electronic countermeasure intelligence system. It's a brand new subject to evaluate the recognition performance scientifically. Formerly most scholars evaluated radar signals recognition methods based on the recognition rate. Aiming at the problem that the evaluation index of recognition effect evaluation of radar signals is single, the paper proposes new evaluation indices. In this paper Analytic Hierarchy Process (AHP) is used to determine the weight of each index, and relevant evaluation model is established for performance evaluation. Simulation result validates that the evaluation model is effective and has certain application prospect. © Springer-Verlag Berlin Heidelberg 2012.

Li J.,Wuhan Electronic Information Institute | Yu L.,Wuhan Electronic Information Institute
Optics Communications | Year: 2016

Photonic generation of arbitrary waveform microwave pulse with tunable carrier frequency and phase based on tunable optoelectronic oscillator (TOEO) and a dual-drive Mach-Zehnder modulator (DDMZM) is proposed. Utilizing the frequency tunability of TOEO, the carrier frequency of the microwave signal can be tuned by adjusting the wavelength of the tunable laser source (TLS) and the tunable range can be as large as tens of GHz. By controlling the signals applied to DDMZM, the generation of arbitrary waveform microwave pulse with tunable phase in the range of -180° to 180° is achieved. The proposed scheme can realize the integration of frequency tuning, phase tuning, pulse modulation and radar transmitted waveform generation in the optical domain, which provides a guarantee of transmitting high-quality microwave signal in radar systems. © 2015 Elsevier B.V.

Chen Y.,Wuhan Electronic Information Institute | Xu F.,AirForce Ordnance Equipments | Qin Z.,Wuhan Electronic Information Institute | Lai X.,Wuhan Electronic Information Institute | Wu K.,Wuhan Electronic Information Institute
2016 IEEE 8th International Power Electronics and Motion Control Conference, IPEMC-ECCE Asia 2016 | Year: 2016

For the modular multilevel converter (MMC) connected with the grid is the most important application. In this paper, an equivalent model of the MMC in the dq synchronous reference is deduced. Different from traditional converter, this model indicates both the inductance and the equivalent capacitance in the ac side would influence the system control. In order to simplify the control to the input currents, the voltage of the inductor and resistor is selected as the control variable and others are taken as disturbance variables. In the outer control loop, the capacitor energy is brought to realize linear control to the system, at the same time, the system power response model is established to deduce the system transformation. Finally, experiment results verify the conclusions and the validity of the mentioned control strategy. © 2016 IEEE.

Wei J.,Nanjing University of Aeronautics and Astronautics | Zhang F.,Nanjing University of Aeronautics and Astronautics | Pan S.,Nanjing University of Aeronautics and Astronautics | Yu L.,Wuhan Electronic Information Institute
European Microwave Week 2015: "Freedom Through Microwaves", EuMW 2015 - Conference Proceedings; 2015 45th European Microwave Conference Proceedings, EuMC | Year: 2015

A compact scheme for stable frequency dissemination over optical fiber is proposed and demonstrated. A standard signal in the center station is delivered to the remote end without any assistant signal source. The frequency of the received signal is the same as the signal source in the center station. A proof-of-concept experiment is performed. A 6-GHz standard signal is transmitted in a 20-km fiber. The phase jitter of the transmission was reduced from more than 41 ps to less than 1.17 ps. © 2015 EuMA.

Peng X.-N.,Hubei University | Wang Y.-L.,Wuhan Electronic Information Institute | Wang H.,Hubei University
Chinese Physics Letters | Year: 2015

The time-dependence evolution of the extinction spectra of the silver nanoplates is studied to analyze the underlying physical mechanism of the growth process. As the synthesis cycles increase, the wavelength of the absorption peak is first blue-shifted and then is followed by the red shift, attributing to the mode alteration of the longitudinal surface plasmon resonance of the silver nanoplates. The capping agents are also optimized for the convenient and speedy growth of the large integrated Ag nanostructure. These observations expand the comprehensive understanding of plasmon resonance of the Ag nanoplates, and give a better manipulation of their applications in the plasmonic nanodevices. © 2015 Chinese Physical Society and IOP Publishing Ltd.

Sun J.,Wuhan Electronic Information Institute | Yu L.,Wuhan Electronic Information Institute | Zhong Y.,Wuhan Electronic Information Institute
Optics Communications | Year: 2014

A novel single sideband (SSB) radio-over-fiber (ROF) system based on a dual-electrode dual-parallel Mach-Zehnder modulator (DE-DPMZM) is proposed, in which the Mach-Zehnder modulator (MZM) is used to produce a single sideband signal and the dual-parallel structure is used to suppress the third-order intermodulation distortion (IMD3) to improve the spurious-free dynamic range (SFDR) of the ROF system. A theoretical analysis is given and simulation experiment is carried out. The results show that the proposed scheme can improve 25 dB in SFDR which is up to 127.854 dB Hz2/3 compared with the conventional SSB ROF system. In addition, the single sideband modulation can extend the transmission distance of optic signal. © 2014 Elsevier B.V. All rights reserved.

Li J.,Wuhan Electronic Information Institute | Yu L.,Wuhan Electronic Information Institute
ICOCN 2015 - 14th International Conference on Optical Communications and Networks, Proceedings | Year: 2015

A novel photonic approach based on optoelectronic oscillator (OEO) to generate phase-coded pulsed microwave signals with tunable frequency and phase is proposed in the paper. The frequency of the microwave signal can be tuned by changing the wavelength of the optical carrier. The modulating signal is applied to a polarization modulator (PolM) for the generation of the phase-coded optical signal with a tunable phase. The modulated optical signal is sent to the photodetector through an electronically tunable polarizer. By tuning the principal axis of the electronically tunable polarizer, the intensity-modulated signal is obtained, which leads to the generation of the pulsed microwave signal with tunable frequency and phase. The generation of the phase-coded pulsed microwave signals is simulated at MATLAB environment. The approach proposed in this paper has a significant value for phased array beam forming and arrayed signal processing. © 2015 IEEE.

Wang B.,Wuhan Electronic Information Institute | Wang L.,Wuhan Electronic Information Institute | Du Q.,Wuhan Electronic Information Institute
Proceedings - 2013 International Conference on Information Technology and Applications, ITA 2013 | Year: 2013

Systemic EMC evaluation method for missile is presented in the paper for the first time. Systemic EMC performance EMC(S) is defined. EMC probability and interfered probability for sensitive port of receivers and other sensitive equipments are defined as well. EMC(S) evaluation system is founded based on interfered relationship matrices. EMC(S) can be evaluated along with the change of subsystem parameters. It is the foundation of EMC optimized design for missile system. © 2013 IEEE.

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