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An interference suppression algorithm for cognitive bistatic airborne radars

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Journal of Systems Engineering and Electronics 2022年第3期33卷 585-593页

作者： XIA Deping ZHANG Liang WU Tao HU Wenjun National Laboratory of Radar Signal Processing Xidian UniversityXi’an 710071China Nanjing Research Institute of Electronics Technology Nanjing 210039China

interference suppression is a challenge for radar researchers, especially when mainlobe and sidelobe interference coexist. We present a comprehensive anti-interference approach based on a cognitive bistatic airborne radar. The risk of interception is reduced by lowering the launch energy of the radar transmitting terminal in the direction of interference;main lobe and sidelobe interferences are suppressed via cooperation between the two radars. The interference received by a single radar is extracted from the overall radar signal using multiple signal classification(MUSIC), and the interference is cross-located using two different azimuthal angles. Neural networks allowing good, non-linear nonparametric approximations are used to predict the location of interference, and this information is then used to preset the transmitting notch antenna to reduce the likelihood of interception. To simultaneously suppress mainlobe and sidelobe interferences, a blocking matrix is used to mask mainlobe interference based on azimuthal information, and an adaptive process is used to suppress sidelobe interference. Mainlobe interference is eliminated using the data received by the two radars. Simulation verifies the performance of the model.

关键词： interference suppression cognitive bistatic airborne radar neural network blocking matrix

FM interference suppression for PRC-CW radar based on adaptive STFT and time-varying filtering

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Journal of Systems Engineering and Electronics 2010年第2期21卷 219-223页

作者： Zhao Zhao Xiangquan Shi School of Electronic Engineering and Optoelectric Technology Nanjing University of Science and Technology Nanjing 210094 E R. China

The influence of frequency modulation （FM） interfer- ence on correlation detection performance of the pseudo random code continuous wave （PRC-CW） radar is analyzed. It is found that the correlation output deteriorates greatly when the FM inter- ference power exceeds the anti-jamming limit of the radar. Accord- ing to the fact that the PRC-CW radar echo is a wideband pseudo random signal occupying the whole TF plane, while the FM in- terference only concentrates in a small portion, a new method is proposed based on adaptive short-time Fourier transform （STFT） and time-varying filtering for FM interference suppression. This method filters the received signal by using a binary mask to excise only the portion of the TF plane corrupted by the interference. Two types of interference, linear FM （LFM） and sinusoidal FM （SFM）, under different signal-to-jamming ratio （S JR） are studied. It is shown that the proposed method can effectively suppress the FM interference and improve the performance of target detection.

关键词： interference suppression frequency modulation in- terference adaptive short-time Fourier transform (STFT) time- varying filtering pseudo random code continuous wave (PRC-CW) radar.

Joint adaptive power allocation and interference suppression algorithms based on the MSER criterion for wireless sensor networks

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第10期15卷 917-928页

作者： Gui-jie WANG Yun-long CAI Min-jian ZHAO Jie ZHONG Department of Information Science and Electronic Engineering Zhejiang University

In this study, a two-hop wireless sensor network with multiple relay nodes is considered where the amplify-and-forward(AF) scheme is employed. Two algorithms are presented to jointly consider interference suppression and power allocation(PA) based on the minimization of the symbol error rate(SER) criterion. A stochastic gradient(SG) algorithm is developed on the basis of the minimum-SER(MSER) criterion to jointly update the parameter vectors that allocate the power levels among the relay sensors subject to a total power constraint and the linear receiver. In addition, a conjugate gradient(CG) algorithm is developed on the basis of the SER criterion. A centralized algorithm is designed at the fusion center. Destination nodes transmit the quantized information of the PA vector to the relay nodes through a limited-feedback channel. The complexity and convergence analysis of the proposed algorithms are carried out. Simulation results show that the proposed two adaptive algorithms significantly outperform the other previously reported algorithms.

关键词： Cooperative communications Adaptive filtering Symbol error rate(SER) interference suppression Power allocation

Study on interference suppression based on joint fractional Fourier domain and time domain

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Science China(Technological Sciences) 2011年第10期54卷 2674-2686页

作者： HUANGKeWu TAO Ran WU Kui WANG Yue Department of Electronic Engineering Beijing Institute of Technology Beijing 100081 China Institute of Manned Space System Engineering China Academy of Space Technology Beijing 100094 China

An interference suppression algorithm is proposed to meet challenges of the traditional technique in dealing with the linear frequency modulation(LFM) interference,such as high loss of signal-to-noise ratio(SNR),the output signal-to-interfer-ence-plus-noise ratio(SINR) sensitive to input interference-to-signal ratio(ISR) that results in an unstable synchronization,and the spectrum leakage serious in strong ISR *** approach firstly makes use of the windowed and lapped technique to the fractional Fourier transform(FRFT) to enhance the ISR improvement and lower the SNR *** by weakening the interference and a secondary threshold process,interference energy can be suppressed as much as possible and the output SINR is less sensitive to the ***,a joint fractional Fourier domain and time domain technique is proposed to overcome the residual interference energy caused by the strong interference or the discontinuous-phase *** analysis and simulation results show that the proposed algorithm can achieve better performance than the conventional methods in suppressing both the multi period LFM interference and the multi chirp-rate LFM interference,especially in the strong interference environment.

关键词： fractional Fourier transform linear frequency modulation interference interference suppression direct sequence spread spectrum

Analysis and Compensation of Frequency Offset in Co-Site Adjacent Channel interference suppression

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China Communications 2023年第6期20卷 116-128页

作者： Xiaolei Huo Wenbo Guo Ying Liu Hongzhi Zhao Youxi Tang National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengdu 611731China Department of Electronic and Optical Engineering Shijiazhuang Campus of Army Engineering UniversityShijiazhuang 050003China

Due to the mismatch of the circuit oscillators,there will always be a frequency offset between the transmitter and the *** the adjacent channel interference(ACI)suppression system using the reconstruction and cancellation method,the frequency offset decreases the accuracy of the reconstructed signal and introduces a time-varying term in the interference cancellation,resulting in poor performance of the ACI *** this paper,the relationship between the normalized frequency offset,signal-to-noise ratio and the loss of interference suppression capability is analyzed through formula derivation and *** validity of the frequency offset compensation method based on the pilot sequence is verified,and the relationship between the sequence length and the estimation accuracy is *** paper provides necessary method reference and data support for the engineering of ACI suppression.

关键词： ACI non-linear distortion parameter estimation interference suppression

An ISS-OFDM based adaptive filtering mechanism for interference suppression in wireless multi-hop communication network

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High Technology Letters 2014年第3期20卷 230-236页

作者：秦丹阳 Ma Lin Xu Renheng Ding Qun Key Laboratory of Electronics Engineering Heilongjiang University Communication Research Center Harbin Institute of Technology Harbin Research Institute of Electrical Instruments

The negative impact on communication performance in wireless multi-hop communication net-work caused by limited bandwidth,high bit eror rate （BER）,fading,noise and interference is alleviated by an adaptive filtering game based on frequency subbands selection and predetemined *** threshold is being obtained in Gaussian and multipath fading channel according to the frequency-matching principle and BER *** dynamic selection of subbands will obtain high use efficiency without the help of frequency hopping,and propound a new thought to improve band limited communication for wireless multi-hop communication *** effectiveness of the adaptive filtering method has been verified by interleaving spread spectrum orthogonal frequency division multiplexing （ISS-OFDM） in different interference conditions,and the simulating results based on network simulator 2 （NS2） indicate that system BER can be improved greatly.

关键词： multi-hop communication adaptive filtering interleaving spread spectrum orthogonal frequency division multiplexing (ISS-OFDM) interference suppression

Code-aided interference suppression in Direct Sequence Spread Spectrum Systems with Eigenvector Sign Spreading Code

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Journal of Shanghai Jiaotong university(Science) 2009年第3期14卷 350-353页

作者：王澄应忍冬杨宇航 Department of Electronic Engineering Shanghai Jiaotong University

For direct sequence spread spectrum (DSSS) communication systems suffering interference, it is known that code-aided interference suppression technique outperforms all of the previous linear or nonlinear methods. In this paper, we proposed an improved code-aided technique which can improve the system performance greatly by using the eigenvector sign (EVS) spreading sequence which depends on the statistical characteristics of the interference and the thermal noise.

关键词： interference suppression direct sequence spread spectrum (DSSS) code-aided technique eigenvector sign (EVS) sequence

SUBSET PARALLEL VOLTERRA FILTER FOR NARROWBAND interference suppression IN DSSS COMMUNICATIONS

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Journal of Electronics(China) 2006年第4期23卷 606-609页

作者： Ma Wenqiang Chen Hao Xi＇an Institute of Space Radio Technology Xi＇an 710000 China

Subset Parallel Adaptive Volterra Filter (SPAVF) design algorithm is proposed in this letter. Contri-bution factor is introduced in SPAVF, and it can get rid of redundant elements efficiently in the extended input vector. Computational weight can be reduced largely, and BER performance of SPAVF can be improved by getting rid of the influence of redundant elements in the input vector. Simulation result proves its advantage compared to AVF and PSVF.

关键词： Volterra filter Direct Sequence Spectrum Spreading(DSSS) interference suppression Subset vector

Improved DSE-CMA Error Function for Blind Multiuser interference suppression in DS/CDMA Systems

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Journal of Shanghai University(English Edition) 2005年第5期9卷 429-431页

作者：赵海波胡光锐朱丽平 Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200030 P. R. China

This paper presents an improved error function of dithered signed-error constant modulus algorithm （IDSE-CMA） for blind multiuser interference suppression in DS/CDMA systems. It uses a different error function to replace the former one in sign operation of the DSE-CMA and compares their performance in multiple access interference （MAI） suppression ability. Simulations indicate that the new algorithm has better performance than the similar CMA in terms of convergence speed and steady-state performance：

关键词： interference suppression constant modulus algorithm(CMA) CDMA.