The ambiguity function of Chinese standard Digital Television Terrestrial Broadcasting (DTTB) signals for passive radar contains one main peak and many side peaks. The side peaks may cause the false alarms. The relati...The ambiguity function of Chinese standard Digital Television Terrestrial Broadcasting (DTTB) signals for passive radar contains one main peak and many side peaks. The side peaks may cause the false alarms. The relative positions and the reasons for the side peaks are analyzed and a new algorithm for side peaks suppression is proposed in this paper. The algorithm, in consideration of the characteristics of the structure of the frame, can eliminate the side peaks completely in the valid Doppler observation interval by setting the reference signals to zero at equal intervals. Both the simulative and experimental results show that this algorithm can improve the performance of target detection of the passive radar based on DTTB signal.展开更多
Link16 data link is the communication standard of the joint tactical information distribution system(JTIDS)used by the U.S.military and North Atlantic Treaty Organization,which is applied as the opportunistic illumina...Link16 data link is the communication standard of the joint tactical information distribution system(JTIDS)used by the U.S.military and North Atlantic Treaty Organization,which is applied as the opportunistic illuminator for passive radar in this paper.The time-domain expression of the Link16 signal is established,and its ambiguity function expression is derived.The timedelay dimension and Doppler dimension side peaks of which lead to the appearance of the false target during target detection.To solve the problem,the time-delay dimension and Doppler dimension side peaks suppression methods are proposed.For the problem that the conventional mismatched filter(MMF)cannot suppress the time-delay dimension side peaks,a neighborhood MMF(NMMF)is proposed.Experimental results demonstrate the effectiveness of the proposed methods.展开更多
Passive radar detects moving targets by Cross Ambiguity Function (CAF), which is based on the cross correlation process of the direct-path signal in reference channel and echo signal in receive channel. Thus, the perf...Passive radar detects moving targets by Cross Ambiguity Function (CAF), which is based on the cross correlation process of the direct-path signal in reference channel and echo signal in receive channel. Thus, the performance of direct-path signal is important to system performance for this type of radar. While the Signal to Noise Ratio (SNR) of direct-path signal is low, it will deteriorate the detection performance. In this paper, how SNR of direct-path signal induces degradation on the SNR of CAF, and how the integration gain affects by integration time are analyzed, both with theoretical analysis and numerical simulation, which are valuable for the R&D of passive radar.展开更多
Passive radar is one of the current research focuses. The implementation of the Chinese standard digital television terrestrial broadcasting （DTTB） creates a new opportunity for passive radar. DTTB system contains s...Passive radar is one of the current research focuses. The implementation of the Chinese standard digital television terrestrial broadcasting （DTTB） creates a new opportunity for passive radar. DTTB system contains single-carrier and multicarrier application modes. In this paper, ambiguity functions of the D＇I-I＇B signals in the single-carrier and multicarrier application modes are analyzed. Ambiguity function of the DTTB signal contains one main peak and many side peaks. The relative positions and amplitudes of the side peaks are derived and the reasons for the occurrence of the side peaks are obtained. The side peaks identification （SPI） algorithm is proposed for avoiding the false alarms caused by the side peaks. Experimental results show that the SPI algorithm can indentify all the side peaks without the power loss. This research provides the foundation for designing the DTTB based passive radar.展开更多
In modern radar techniques, pulse signal can be replaced by the chirps, which is taken to be signals in Lp space. Wigner’s function and ambiguity functions are constructed in an Lp frame and a partial generalization ...In modern radar techniques, pulse signal can be replaced by the chirps, which is taken to be signals in Lp space. Wigner’s function and ambiguity functions are constructed in an Lp frame and a partial generalization of the uncertainty principle is given by means of the notion of coherent dual.展开更多
A novel modified optimization technique known as the multi-objective micro particle swarm optimization（MO-MicPSO） is proposed for polyphase coded signal design.The proposed MO-MicPSO requires only a small population...A novel modified optimization technique known as the multi-objective micro particle swarm optimization（MO-MicPSO） is proposed for polyphase coded signal design.The proposed MO-MicPSO requires only a small population size compared with the standard particle swarm optimization that uses a larger population size.This new method is guided by an elite archive to finish the multi-objective optimization.The orthogonal polyphase coded signal（OPCS） can fundamentally improve the multiple input multiple output（MIMO） radar system performance,with which the radar system has high resolution and abundant signal channels.Simulation results on the polyphase coded signal design show that the MO-MicPSO can perform quite well for this high-dimensional multi-objective optimized problem.Compared with particle swarm optimization or genetic algorithm,the proposed MO-MicPSO has a better optimized efficiency and less time consumption.展开更多
Taking the relativistic effect of high velocity moving target into account, the Doppler shift, polarization deflection, reflection coefficient and phase delay of reflected electric field are analyzed rigorously under...Taking the relativistic effect of high velocity moving target into account, the Doppler shift, polarization deflection, reflection coefficient and phase delay of reflected electric field are analyzed rigorously under the assumptions that incident signal to the target is a plane wave and the target is a perfect conductor plane; and their analytic expressions are obtained. The present results are of practical significance to some extent for the accurate expression of the wideband returned signal of a high velocity moving target in the bistatic radar system and for the understanding of wideband ambiguity functions.展开更多
在基于全球移动通信(global system for mobile communication,GSM)信号的外辐射源雷达中,不仅有能量很强的基站直达波和强多径干扰,同时还存在大量的弱干扰,单独利用自适应波束形成和低副瓣技术很难完全有效抑制所有的干扰信号。提出...在基于全球移动通信(global system for mobile communication,GSM)信号的外辐射源雷达中,不仅有能量很强的基站直达波和强多径干扰,同时还存在大量的弱干扰,单独利用自适应波束形成和低副瓣技术很难完全有效抑制所有的干扰信号。提出一种基于两步空域滤波的GSM辐射源雷达干扰抑制方法,首先利用低副瓣技术对弱干扰进行抑制,然后利用一种稳健的自适应波束形成方法对残留的强干扰信号作进一步抑制,计算机仿真结果验证了本文方法的有效性。展开更多
全球移动通信(Global System for Mobile communication,GSM)信号已经被很多文献证明可以作为外辐射源雷达的机会照射源信号,但是在以往的研究中主要考虑抑制主基站的直达波和多径干扰.而实际上,GSM辐射源雷达不仅受到主基站的干扰,还...全球移动通信(Global System for Mobile communication,GSM)信号已经被很多文献证明可以作为外辐射源雷达的机会照射源信号,但是在以往的研究中主要考虑抑制主基站的直达波和多径干扰.而实际上,GSM辐射源雷达不仅受到主基站的干扰,还受到其它同频基站的干扰.为了消除主基站干扰,同时抑制其它同频基站的干扰,本文提出首先利用扩展相消算法(Extensive Cancellation Algorithm,ECA)在时域上消除主基站的干扰,然后利用基于最差性能最优准则的稳健自适应波束形成在空域上对其它同频基站干扰进行抑制.最后仿真分析表明本文提出的杂波抑制方法的有效性.展开更多
Recognition and correction of ionospheric phase path contamination is a vital part of the global radar signal processing sequence. A number of model-based correction algorithms have been developed to deal with the rad...Recognition and correction of ionospheric phase path contamination is a vital part of the global radar signal processing sequence. A number of model-based correction algorithms have been developed to deal with the radar performance degradation due to the ionospheric distortion and contamination. This paper addresses a novel parametric estimation and compensation method based on High-order Ambiguity Function (HAF) to solve the problem of phase path contamination of HF skywave radar signals. When signal-to-noise ratio and data sequence available satisfy the predefined conditions, the ionospheric phase path contamination may be modeled by a polynomial phase signal (PPS). As a new parametric tool for analyzing the PPS, HAF is introduced to estimate parameters of the polynomial-phase model and reconstruct the correction signal. Using the reconstructed correction signal, compensation can be performed before coherent integration so that the original echo spectrum can be restored. A piecewise scheme is proposed to track rapid variation of the phase contamination based on HAF method, and it can remove the Doppler spread effect caused by the ionosphere nonstationarity. Simulation and experimental results are given to demonstrate the efficiency of the proposed algorithm.展开更多
文摘The ambiguity function of Chinese standard Digital Television Terrestrial Broadcasting (DTTB) signals for passive radar contains one main peak and many side peaks. The side peaks may cause the false alarms. The relative positions and the reasons for the side peaks are analyzed and a new algorithm for side peaks suppression is proposed in this paper. The algorithm, in consideration of the characteristics of the structure of the frame, can eliminate the side peaks completely in the valid Doppler observation interval by setting the reference signals to zero at equal intervals. Both the simulative and experimental results show that this algorithm can improve the performance of target detection of the passive radar based on DTTB signal.
基金the National Natural Science Foundation of China(61401526).
文摘Link16 data link is the communication standard of the joint tactical information distribution system(JTIDS)used by the U.S.military and North Atlantic Treaty Organization,which is applied as the opportunistic illuminator for passive radar in this paper.The time-domain expression of the Link16 signal is established,and its ambiguity function expression is derived.The timedelay dimension and Doppler dimension side peaks of which lead to the appearance of the false target during target detection.To solve the problem,the time-delay dimension and Doppler dimension side peaks suppression methods are proposed.For the problem that the conventional mismatched filter(MMF)cannot suppress the time-delay dimension side peaks,a neighborhood MMF(NMMF)is proposed.Experimental results demonstrate the effectiveness of the proposed methods.
文摘Passive radar detects moving targets by Cross Ambiguity Function (CAF), which is based on the cross correlation process of the direct-path signal in reference channel and echo signal in receive channel. Thus, the performance of direct-path signal is important to system performance for this type of radar. While the Signal to Noise Ratio (SNR) of direct-path signal is low, it will deteriorate the detection performance. In this paper, how SNR of direct-path signal induces degradation on the SNR of CAF, and how the integration gain affects by integration time are analyzed, both with theoretical analysis and numerical simulation, which are valuable for the R&D of passive radar.
基金Supported by the National Natural Science Foundation of China (Grant No. 60232010)the Ministerial Foundation of China (Grant No.A2220060039)the National Natural Science Foundation of China for Distinguished Young Scholars (Grant No. 60625104)
文摘Passive radar is one of the current research focuses. The implementation of the Chinese standard digital television terrestrial broadcasting （DTTB） creates a new opportunity for passive radar. DTTB system contains single-carrier and multicarrier application modes. In this paper, ambiguity functions of the D＇I-I＇B signals in the single-carrier and multicarrier application modes are analyzed. Ambiguity function of the DTTB signal contains one main peak and many side peaks. The relative positions and amplitudes of the side peaks are derived and the reasons for the occurrence of the side peaks are obtained. The side peaks identification （SPI） algorithm is proposed for avoiding the false alarms caused by the side peaks. Experimental results show that the SPI algorithm can indentify all the side peaks without the power loss. This research provides the foundation for designing the DTTB based passive radar.
文摘In modern radar techniques, pulse signal can be replaced by the chirps, which is taken to be signals in Lp space. Wigner’s function and ambiguity functions are constructed in an Lp frame and a partial generalization of the uncertainty principle is given by means of the notion of coherent dual.
基金supported by the National Natural Science Foundation of China (60601016)
文摘A novel modified optimization technique known as the multi-objective micro particle swarm optimization（MO-MicPSO） is proposed for polyphase coded signal design.The proposed MO-MicPSO requires only a small population size compared with the standard particle swarm optimization that uses a larger population size.This new method is guided by an elite archive to finish the multi-objective optimization.The orthogonal polyphase coded signal（OPCS） can fundamentally improve the multiple input multiple output（MIMO） radar system performance,with which the radar system has high resolution and abundant signal channels.Simulation results on the polyphase coded signal design show that the MO-MicPSO can perform quite well for this high-dimensional multi-objective optimized problem.Compared with particle swarm optimization or genetic algorithm,the proposed MO-MicPSO has a better optimized efficiency and less time consumption.
文摘Taking the relativistic effect of high velocity moving target into account, the Doppler shift, polarization deflection, reflection coefficient and phase delay of reflected electric field are analyzed rigorously under the assumptions that incident signal to the target is a plane wave and the target is a perfect conductor plane; and their analytic expressions are obtained. The present results are of practical significance to some extent for the accurate expression of the wideband returned signal of a high velocity moving target in the bistatic radar system and for the understanding of wideband ambiguity functions.
文摘在基于全球移动通信(global system for mobile communication,GSM)信号的外辐射源雷达中,不仅有能量很强的基站直达波和强多径干扰,同时还存在大量的弱干扰,单独利用自适应波束形成和低副瓣技术很难完全有效抑制所有的干扰信号。提出一种基于两步空域滤波的GSM辐射源雷达干扰抑制方法,首先利用低副瓣技术对弱干扰进行抑制,然后利用一种稳健的自适应波束形成方法对残留的强干扰信号作进一步抑制,计算机仿真结果验证了本文方法的有效性。
文摘全球移动通信(Global System for Mobile communication,GSM)信号已经被很多文献证明可以作为外辐射源雷达的机会照射源信号,但是在以往的研究中主要考虑抑制主基站的直达波和多径干扰.而实际上,GSM辐射源雷达不仅受到主基站的干扰,还受到其它同频基站的干扰.为了消除主基站干扰,同时抑制其它同频基站的干扰,本文提出首先利用扩展相消算法(Extensive Cancellation Algorithm,ECA)在时域上消除主基站的干扰,然后利用基于最差性能最优准则的稳健自适应波束形成在空域上对其它同频基站干扰进行抑制.最后仿真分析表明本文提出的杂波抑制方法的有效性.
文摘Recognition and correction of ionospheric phase path contamination is a vital part of the global radar signal processing sequence. A number of model-based correction algorithms have been developed to deal with the radar performance degradation due to the ionospheric distortion and contamination. This paper addresses a novel parametric estimation and compensation method based on High-order Ambiguity Function (HAF) to solve the problem of phase path contamination of HF skywave radar signals. When signal-to-noise ratio and data sequence available satisfy the predefined conditions, the ionospheric phase path contamination may be modeled by a polynomial phase signal (PPS). As a new parametric tool for analyzing the PPS, HAF is introduced to estimate parameters of the polynomial-phase model and reconstruct the correction signal. Using the reconstructed correction signal, compensation can be performed before coherent integration so that the original echo spectrum can be restored. A piecewise scheme is proposed to track rapid variation of the phase contamination based on HAF method, and it can remove the Doppler spread effect caused by the ionosphere nonstationarity. Simulation and experimental results are given to demonstrate the efficiency of the proposed algorithm.
