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Design of Orthogonal polyphase code Set Based on Multipulse Joint Processing

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2024年第6期60卷 8901-8913页

作者： Bai, Jiahao Wei, Guohua Shao, Jingkai Wang, Xu Fei, Zesong Beijing Inst Technol Sch Informat & Elect Beijing 100081 Peoples R China

The orthogonality of multiple-input multiple-output radar transmission signals can be improved without changing the operating parameters of the radar through multipulse joint processing. An efficient echo processing algorithm and optimization criteria for a phase-coded set suitable for multipulse joint processing are introduced in this article. The characteristics of both the normalized auto-ambiguity function and the cross-ambiguity function of the signals are considered in the optimization objective. In order to effectively improve the efficiency of generating phase-coded sets while ensuring signal orthogonality, an accelerated optimization algorithm based on global search combined with local search is proposed in this article. More specifically, computational complexity is reduced by avoiding a large number of unnecessary calculations during the updating of the ambiguity functions after the code set is perturbed. The orthogonality gain brought by the optimization algorithm proposed in this article, as well as the time advantage of the accelerated optimization algorithm, is verified by simulation results.

关键词： codes MIMO radar Transmitting antennas Radar antennas Doppler effect Optimization Receiving antennas Multiple-input multiple-output (MIMO) radar multipulse joint processing orthogonal signal polyphase code

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A Digital False-Target Image Synthesizer Method Against ISAR Based on polyphase code and Sub-Nyquist Sampling

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IEEE GEOSCIENCE AND REMOTE SENSING LETTERS 2020年第3期17卷 372-376页

作者： Li, Guang-Ming Zhang, Qun Su, Ling-Hua Luo, Ying Liang, Jia Air Force Engn Univ Inst Informat & Nav Xian 710077 Peoples R China Collaborat Innovat Ctr Informat Sensing & Underst Xian 710077 Peoples R China Fudan Univ Minist Educ Key Lab Informat Sci Electromagnet Waves Shanghai 200433 Peoples R China

Digital false-target image synthesizer (DIS) has been proposed as a deceptive jamming method against inverse synthetic aperture radar (ISAR). The DIS method based on sub-Nyquist sampling jamming has attracted increasing attention in recent years. However, multiple false-target images generated by sub-Nyquist sampling jamming are distributed in the down-range direction rather than the 2-D range-Doppler (RD) imaging plane. A novel DIS method is proposed in this letter. First, an additional phase controlled by polyphase code is added to the intercepted pulse, and the multiple false-target images will be induced regularly along the cross-range direction. Second, in order to generate false-target images both along the down-range and cross-range directions, the sub-Nyquist sampling theory is applied to the first step. The advantage of the proposed method is implementation simplicity. Experimental results verify the effectiveness of the proposed method.

关键词： Jamming Radar Doppler effect Synthesizers Imaging Modulation Aerospace electronics Digital false-target image synthesizer (DIS) inverse synthetic aperture radar (ISAR) polyphase code sub-Nyquist sampling jamming

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CDMA in Metamaterials Using polyphase codes

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IEEE ACCESS 2024年 12卷 21207-21216页

作者： Syms, Richard R. A. Voronov, Artem Imperial Coll London Dept Elect & Elect Engn London SW7 2BX England

Small code sets are required for asynchronous code division multiple access (CDMA) communication in dispersive channels such as metamaterials, for applications including communications in conductive environments and wireless power transfer. Desirable properties of such codes include low autocorrelation sidelobes, low cross correlations, and low bandwidth. Pairs of polyphase codes in bases 2, 3, 4, 5 and 6 are investigated using a rapid numerical sieve with a spectral cost function. Optimum codes are selected from complex conjugate pairs with equal spectral costs, and codes with minimum bandwidth are identified for lengths up to 12 for all except base 2. coded signaling and CDMA are investigated by simulation and experiment at high frequency (HF) in example metamaterial, a magneto-inductive waveguide.

关键词： codes Costs Autocorrelation Metamaterials Media Dispersion Multiaccess communication code division multiple access magneto-inductive waveguide metamaterial polyphase code

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Parameter Estimation of polyphase code Signals Based on Periodic FRFT

Parameter Estimation of Polyphase Code Signals Based on Peri...

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2016 International Conference on Artificial Intelligence and Engineering Applications (AIEA 2016)

作者： Jiandong Zhu Tengfei Jia Yanfei Wei Zhiqiang Ji Youyi Fan Junkui Xu Electronic Test Equipment Center

ISBN: (纸本)9781510835443

In order to improve the ability to intercepting polyphase code continuous wave signals for the radar reconnaissance receiver, a polyphase code continuous wave signals detection algorithm based on Periodic Fractional Fourier transform(Periodic FRFT, PFRFT) is *** this paper, the PFRFT and its properties of linear frequency modulated continuous wave signals are *** the characteristics of linear frequency modulated continuous wave(LFMCW) signals of polyphase code continuous wave signals is *** to the similarity between the polyphase code continuous wave signals and the linear frequency modulated continuous wave signals, a polyphase code continuous wave signals detection algorithm based on PFRFT is proposed, also the realization process is given, and then the detection performance and parameter estimation performance are *** results show that, compared with other existing algorithms, the proposed algorithm has better ability to detecting weak signal, and the minimum detectable signal to noise ratio(SNR) can be reduced by at least 6 d B, which is further reduced with the observation time extended.

关键词： Radar reconnaissance polyphase code continuous wave signal detection Periodic FRFT

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polyphase codes for multiplexed acoustic signalling and sensing on pipes

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SMART MATERIALS AND STRUCTURES 2022年第9期31卷 095033-095033页

作者： Syms, Richard R. A. Noorwali, Aiman Imperial Coll London Elect & Elect Engn Dept London England

Transmission of acoustic signals between distributed sensor nodes may be useful for status monitoring of elongated structures such as pipelines. In principle, coded signals can be used in an asynchronous multiplexed system, provided the signals are distinguishable. However, multimode effects complicate signal propagation, so any such codes should be short. A search for polyphase code families with properties suitable for acoustic code division multiple access is presented. Algorithms for reduction of search space to allow use of a laptop for code discovery are described. Short codes of base 6 are shown to outperform codes of bases 2, 3, 4 and sets suitable for systems with 2 and 3 users are identified. The codes have similar properties to Barker codes but larger sidelobes. Their use is demonstrated by simulation and experiment at kHz frequencies using an air-filled copper pipe, an electromagnetic acoustic transducer (EMAT) and a microphone designed to excite and detect the L (0, 1) mode. Low loss propagation over 25 m is achieved with a 20 kHz carrier. Excellent agreement between experiment and theory is demonstrated, with performance limited by transducer bandwidth.

关键词： acoustic wave EMAT polyphase code correlation detection

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MIMO FMCW Radar with Doppler-Insensitive polyphase codes

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REMOTE SENSING 2022年第11期14卷 2595-2595页

作者： Kim, EunHee Sejong Univ Dept Def Syst Engn 209 Neungdong Ro Seoul 05006 South Korea

Co-located MIMO is used to enlarge the antenna aperture virtually and increase the angular resolution. This paper shows FMCW radar using MIMO VAA. polyphase codes are designed for modulating the successive chirps of transmitting signals. The codes are optimized to have low cross-correlations regardless of the Doppler filter mismatch. Compared with orthogonal codes, the designed codes show robust performance for Doppler mismatch and lower angle estimation errors. The entire procedure is explained, and the simulation results are provided.

关键词： FMCW radar MIMO VAA polyphase code simulated annealing algorithm

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Search for Generalized MPS and Barker Sequences

Search for Generalized MPS and Barker Sequences

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IEEE Radar Conference (RadarConf)

作者： Coxson, Gregory E. Russo, Jon C. US Naval Acad Annapolis MD 21402 USA Lockheed Martin ATL Cherry Hill NJ USA

ISBN: (纸本)9781728153681

The lowest achievable PSL for mth-root-of-unity codes are found by several search approaches, including exhaustive search and an evolutionary algorithm, for lengths 2 <= N <= 15 and 2 <= m <= 20. Tabulation of the findings reveals patterns that may be used to inform searches for cases that remain un-resolved. Generalized Barker sequences were found for m = 6 for each N between 2 and 15, which implies that for these lengths, the same holds true when m is any multiple of 6. The findings suggest that generalized Barker sequences are not that rare, at least as far as cases N x m that harbor them.

关键词： peak sidelobe level autocorrelation MPS code generalized Barker sequence polyphase code

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A New Approach for Enhanced Detection Using Chirp Reference Signals 92

A New Approach for Enhanced Detection Using Chirp Reference ...

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92nd IEEE Vehicular Technology Conference (IEEE VTC-Fall)

作者： Martinez, Ana Belen Kumar, Atul Chafii, Marwa Fettweis, Gerhard Tech Univ Dresden Vodafone Chair Mobile Commun Syst Dresden Germany CY Univ ENSEA ETIS CNRS F-95000 Cergy France

ISBN: (纸本)9781728194844

Matched filtering based on linear frequency modulated (LFM) or chirp signals constitutes a reliable approach for frame detection even in the presence of high carrier frequency offsets (CFOs). However, the use of polyphase codes as discrete versions of LFM signals can lead to strong degradation at the output of the matched filter for certain CFO conditions and sequence lengths, yielding missed detection. This work proposes a new approach to improve the probability of detection achievable with matched filtering for these unfavorable situations. The proposed approach exploits the symmetry of a reference sequence that consists of a polyphase code followed by its complex conjugate with an algorithm based on reversed autocorrelation (RC) and successfully utilizes the robustness of RC against CFO for detection. It is shown that joint detection based on matched filtering and RC can enhance the detection performance significantly compared to conventional matched filtering.

关键词： Detection probability matched filter reversed autocorrelation chirp polyphase code carrier frequency offset

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Interpulse-frequency-agile and intrapulse-phase-coded waveform optimisation for extend-range correlation sidelobe suppression

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IET RADAR SONAR AND NAVIGATION 2017年第10期11卷 1530-1539页

作者： Mao, Zhineng Wei, Yinsheng Harbin Inst Technol Dept Elect Engn Xidazhi St 92 Harbin Heilongjiang Peoples R China

Conventional stepped-frequency (SF) waveform utilises the frequency step between pulses to span a wide bandwidth. However, the frequency step size is limited by the width of the pulse to prevent the grating lobes, and the first lobe is about -13dB due to the uniformly sampling in frequency. Modulating the pulses [e.g. phase-coded (PC) modulation or linear frequency modulation] can increase the frequency step size and improve the performance of the sidelobes, but the sidelobes of the modulated SF waveform are still not the best. In this study, a PC frequency-hopping (PCFH) waveform to achieve optimal extend-range correlation sidelobes is presented. The presented waveform applies non-linear frequency evolution, optimal frequency order and different polyphase code to each pulse. In comparison to the SF waveform, the PCFH waveform has much higher degrees of freedom for suppressing extend-range correlation sidelobes. The authors propose a design scheme, which sequentially optimises the interpulse frequency, the FH order and the intrapulse-polyphase code to achieve the optimal extended-range correlation sidelobes. Simulation results validate the performance of the optimised waveform and the feasibility of the involved design method.

关键词： phase coding modulation coding frequency modulation correlation methods optimisation frequency hop communication interpulse-frequency-agile waveform optimisation intrapulse-phase-coded waveform optimisation extend-range correlation sidelobe suppression stepped-frequency waveform SF waveform grating lobes phase-coded modulation PC modulation linear frequency modulation PC frequency-hopping PCFH waveform nonlinear frequency evolution optimal frequency order polyphase code

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Recognition Method Based on Wigner-Hough Transform for Poly-Phase code Radar Signal

Recognition Method Based on Wigner-Hough Transform for Poly-...

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The 13th International Conference on Wireless Communications, Networking and Mobile Computing (WiCOM 2017)

作者： Wenxu Zhang Bing Wang Fuli Sun College of Information and Communication Engineering Harbin Engineering University

In order to solve the recognition of polyphase code radar signal,this paper gives two methods based on Frank code,*** high-order spectrum recognition method and the fractional Fourier transform(FRFT) method,by analyzing the micro characteristics of polyphase code signals in time and frequency domain *** a recognition algorithm based on Wigner-Hough transform(WHT) is developed in this *** verify the validity of each method by computer simulation and give relative merits and demerits.A set of results demonstrate that the algorithm based on Wigner-Hough transform has better recognition performance in low signal-to-noise(SNR) than others.

关键词： Radar Signal Processing polyphase code Fractional Fourier Transform Wigner-Hough Transform

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