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Generalized spatial representation for digital modulation and its potential application

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Science China Earth Sciences 2016年第12期59卷 47-58页

作者： hao huan Pengfei SHI Xiaodong YAN Ran TAO School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China Key Lab for Spacecraft TT&C and Communication under the Ministry of Education Chongqing 400044China

Constellation mapping has provided a great convenience to measure the performance of digital signal modulation in Euclid space. However, traditional in-phase and quadrature(IQ) plane is difficult to express the frequency modulation scheme such as minimum shift keying(MSK) and the time domain modulation such as cyclic code shift keying(CCSK). How to represent the digital signal modulation visually through constellation mapping is an attractive problem. To address this issue, in this paper, the combined frequency and phase modulation are utilized to define a new kind of constellation mapping, where the phase and frequency are quantized to the same elements. The uniform geometric construction for combined phase and frequency modulation is redefined in the 3D cylindrical coordinate system based on frequency(f), in-phase component(I) and quadrature component(Q). In the new coordinates, the quadrature frequency-phase shift keying(QFPSK) is produced by the QPSK with dimensional rotation matrix and denoted by the reduced dual quaternion. Furthermore, the spatial extension from QFPSK to chirp cyclic shift keying(Chirp CSK) is analyzed with bandwidth efficiency and energy efficiency. At last, the QFPSK is combined with the 2D OFDM, yielding the image OFDM *** results verify the effectiveness of QFPSK in the proposed system with the time-varying wireless channel and frequency selective fading channel respectively.

关键词： quadrature frequency-phase shift keying (QFPSK) chirp cyclic shift keying spatial constellation mapping image OFDM system wireless communication

LFM Radar Source Passive Localization Algorithm Based on Range Migration

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Journal of Beijing Institute of Technology 2024年第2期33卷 130-140页

作者： Dandan Li Deyi Wang hao huan Beijing Key Laboratory of Fractional Signals and Systems School of Information and ElectronicsBeijing Institute of TechnologyBeijing 100081China Beijing Aerospace Automatic Control Institute Beijing 100854China

Traditional single-satellite passive localization algorithms are influenced by frequency and angle measurement accuracies,resulting in error estimation of emitter position on the order of ***,a single-satellite localization algorithm based on passive synthetic aper-ture(PSA)was introduced,enabling high-precision ***,its estimation of azimuth and range distance is considerably affected by the residual frequency offset(RFO)of uncoopera-tive system ***,it requires data containing a satellite flying over the radia-tion source for RFO *** estimating the RFO,an accurate estimation of azimuth and range distance can be carried out,which is difficult to achieve in practical *** LFM radar source passive localization algorithm based on range migration is proposed to address the dif-ficulty in estimating frequency *** algorithm first provides a rough estimate of the pulse repetition time(PRT).It processes intercepted signals through range compression,range interpola-tion,and polynomial fitting to obtain range migration ***,it uses the changing information of range migration and an accurate PRT to formulate a system of nonlinear equations,obtaining the emitter position and a more accurate PRT through a two-step localization *** offset only induces a fixed offset in range migration,which does not affect the changing *** algorithm can also achieve high-precision localization in squint ***,the effectiveness of this algorithm is verified through simulations.

关键词： passive localization range migration residual frequency offset

Single-channel sampling and multi-channel reconstruction AIC via multiple chirp noise sequences

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Science China(Information Sciences) 2018年第10期61卷 263-265页

作者： Pengfei SHI hao huan Ran TAO School of Information and Electronics Beijing Institute of Technology Beijing Key Laboratory of Fractional Signals and Systems Beijing Institute of Technology

Dear editor,As preliminary implementation of compressed sensing (CS), the analog-to-information converter(AIC) plays an important role in reducing the sampling rate of analog signals via PN sequence [1,2]. However, it suffers severe reconstruction errors (REs) when acquiring noisy signals prior to measurement in cases with low signal-noise ratio(SNR)[3].To damp the RE, the adaptive weighted norm constraint is first introduced in [4], which enables

关键词： AIC MCR SCS Single-channel sampling and multi-channel reconstruction AIC via multiple chirp noise sequences

Nia1 and Nia2 are Involved in Exogenous Salicylic Acid-induced Nitric Oxide Generation and Stomatal Closure in Arabidopsis

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Journal of Integrative Plant Biology 2010年第3期52卷 298-307页

作者： Fushun hao Shiling Zhao huan Dong huan Zhang Lirong Sun Chen Miao Henan Key Laboratory of Plant Stress Biology College of Life Science Henan University Kaifeng 475004 China

Phytohormone salicylic acid （SA） plays important roles in plant responses to environmental stress. However, knowledge about the molecular mechanisms for SA affecting the stomatal movements is limited. In this paper, we demonstrated that exogenous SA significantly induced stomatal closure and nitric oxide （NO） generation in Arabidopsis guard cells based on genetic and physiological data. These effects were significantly inhibited by the NO scavenger c-PTIO, NO synthase （NOS） inhibitor L-NAME or nitrate reductase suppressor tungstate respectively, implying that NOS and nitrate reductase （NR） participate in SA-evoked stomatal closing. Furthermore, the effects of SA promotion of stomatal closure and NO synthesis are significantly suppressed in NR single mutants of nial, nia2 or double mutant niallnia2, compared with the wild type plants. This suggests that both Nial and Nia2 are involved in SA-stimulated stomatal closure. In addition, pharmacological experiments showed that protein kinases, cGMP and cADPR are involved in SA-mediated NO accumulation and stomatal closure induced by SA in Arabidopsis.

关键词： SALICYLIC acid ARABIDOPSIS PLANT hormones NITRIC oxide TUNGSTATES

MHD Control of Oblique Detonation Waves

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Chinese Physics Letters 2011年第1期28卷 134-137页

作者： SUN Xiao-Hui CHEN Zhi-Hua ZHANG huan-hao Key Laboratory of Transient Physics Nanjing University of Science & Technology Nanjing 210094

Based on the Euler equation, the hybrid Roe/HLL scheme is employed to simulate the oblique detonation waves （ODWs）. Furthermore, ***）＇namic （MHD） control of both stable and unstable ODWs is investigated. It is shown that the stable ODW wave front can be controlled to the desired position under different inflow Mach numbers. However, for an unstable ODW, it is difficult for the MHD control to return the ODW front, but the unstable ODW turns to be stable with the Lorentz force applied in proper direction.

关键词： Fluid dynamics

Radio Frequency Fingerprint-Based Satellite TT&C Ground Station Identification Method

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Journal of Beijing Institute of Technology 2023年第1期32卷 1-12页

作者： Xiaogang Tang Junhao Feng Binquan Zhang hao huan School of Aerospace Information Space Engineering UniversityBeijing 101407China School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

This study presents a radio frequency(RF)fingerprint identification method combining a convolutional neural network(CNN)and gated recurrent unit(GRU)network to identify measurement and control *** proposed algorithm(CNN-GRU)uses a convolutional layer to extract the IQ-related learning timing features.A GRU network extracts timing features at a deeper level before outputting the final identification *** number of parameters and the algorithm’s complexity are reduced by optimizing the convolutional layer structure and replacing multiple fully-connected layers with gated cyclic *** experiments show that the algorithm achieves an average identification accuracy of 84.74% at a -10 dB to 20 dB signal-to-noise ratio(SNR)with fewer parameters and less computation than a network model with the same identification rate in a software radio dataset containing multiple USRP X310s from the same manufacturer,with fewer parameters and less computation than a network model with the same identification *** algorithm is used to identify measurement and control signals and ensure the security of the measurement and control link with theoretical and engineering applications.

关键词： measurement and control security radio frequency(RF)fingerprinting identity identification deep learning

A Residual Frequency Offset Estimation Method Based on Range Migration Fitting

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Journal of Beijing Institute of Technology 2024年第2期33卷 103-110页

作者： Liting Zhang hao huan Ran Tao Xiaogang Tang School of Information and Electronics Beijing Institute of Technology School of Aerospace Information Space Engineering University

Recently, researchers have proposed an emitter localization method based on passive synthetic aperture. However, the unknown residual frequency offset(RFO) between the transmitter and the receiver causes the received Doppler signal to shift, which affects the localization accuracy. To solve this issue, this paper proposes a RFO estimation method based on range migration fitting. Due to the high frequency modulation slope of the linear frequency modulation(LFM)-modulation radar signal, it is not affected by RFO in range compression. Therefore, the azimuth time can be estimated by fitting the peak value position of the pulse compression in range ***, the matched filters are designed under different RFOs. When the zero-Doppler time obtained by the matched filters is consistent with the estimated azimuth time, the given RFO is the real RFO between the transceivers. The simulation results show that the estimation error of azimuth distance does not exceed 20 m when the received signal duration is not less than 3 s, the pulse repetition frequency(PRF) of the transmitter radar signal is not less than 1 k Hz, the range detection is not larger than 1 000 km, and the signal noise ratio(SNR) is not less than –5 d B.

关键词： range migration fitting (RMF) passive localization residual frequency offset (RFO)

Electrochemical Sensor Based on AgNPs-NNH Nanocomposites for Hydrogen Peroxide Detection by Zero Current Potentiometry

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Chinese Journal of Chemistry 2018年第12期36卷 1174-1178页

作者： Yanyi Fu huan hao Xiaoli Liu Jianbin Zhen College of Chemistry & Materials Science Shaanxi Provincial Key Laboratory of Electroanalytical ChemistryNorthwest UniversityXi'anShaanxi 710069China

The layered nickel nitrate hydroxide (NNH) nickel base material was prepared by using hydrothermal method, and the AgNPs were synthesized on the surface of NNH. The layered AgNPs‐NNH nanocomposites were used to construct electrochemical sensor for hydrogen peroxide detection. The morphology, composition and structure of the sensing interface materials were characterized and the relationship between zero current potential signals towards hydrogen peroxide and the response performance was explored. The results of field emission electron microscope (FESEM) and transmission electron microscope (TEM) showed that the NNH was layered material with a uniform thickness of 60 nm, and AgNPs evenly dispersed on the surface of NNH layer, with the size of 15 nm and 23 nm, respectively. Based on zero current potentiometry, the electrochemical results indicated that the linear range was from 1.0 nmol/L to 1.0 mmol/L, with a detection limit of 0.3 nmol/L and a sensitivity of 33.7 μV·mM-1·cm-2. Compared to the chronoamperometry, the detection limit was reduced four orders of magnitude.

关键词： electrochemical electron transfer nanostructures zero current potentiometry chronoamperometry hydrogen peroxide

Constant envelope FrFT OFDM: spectral and energy efficiency analysis

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Journal of Systems Engineering and Electronics 2019年第3期30卷 467-473页

作者： DIDA Mussa Ally huan hao TAO Ran WANG Teng URYNBASSAROVA Didar School of Information and Electronics Beijing Institute of Technology School of Computational and Communication Science and Engineering Nelson Mandela African Institute of Science and Technology

Constant envelope with a fractional Fourier transformorthogonal frequency division multiplexing(CE-FrFT-OFDM) is a special case of a constant envelope OFDM(CE-OFDM), both being energy efficient wireless communication techniques with a 0 dB peak to average power ratio(PAPR). However, with the proper selection of fractional order, the first technique has a high bit error rate(BER) performance in the frequency-time selective *** paper performs further analysis of CE-FrFT-OFDM by examining its spectral efficiency(SE) and energy efficiency(EE) and compare to the famous OFDM and Fr FT-OFDM techniques. Analytical and comprehensive simulations conducted show that, the CE-Fr FT-OFDM has five times the EE of OFDM and Fr FT-OFDM systems with a slightly less SE. Increasing CE-FrFT-OFDM’s transmission power by increasing its amplitude to 1.7 increases its SE to match that of the OFDM and Fr FT-OFDM systems while slightly reducing its EE by 20% to be four times that of OFDM and Fr FTOFDM systems. OFDM and Fr FT-OFDM’s amplitude fluctuations cause rapid changing output back-off(OBO) power requirements and further reduce power amplifier(PA) efficiency while CE-FrFTOFDM stable operational linear range makes it a better candidate and outperforms the other techniques when their OBO exceeds1.7. Higher EE and low BER in time-frequency selective channel are attracting features for CE-FrFT-OFDM deployment in mobile devices.

关键词： fractional Fourier transform(FrFT) constant envelope spectral efficiency(SE) energy efficiency(EE) high power amplifier