Abstract:Global Navigation Satellite System(GNSS)-based passive radar is a hotspot of current research. In the positioning method based on the sum of distance, the time synchronization error and positioning error of GNSS will reduce the positioning accuracy. Considering the above errors and combining the signal characteristics and parameter measurement capabilities of the four major GNSSs in the world, the three-dimensional localization accuracy expressions and the Cramer-Rao Lower Bound(CRLB) for the system of multi-transmit multi-receive are derived. Through simulation analysis, the relationship between the number of satellites or receiving stations and the localization accuracy is revealed. When the satellite position errors are ignored, the percentage increases in localization accuracy caused by the number increases of receiving stations are the fixed values for any number of radiation sources; if the satellite position errors increase, the improvement in positioning accuracy by increasing the number of receiving stations will decrease. The obtained conclusions can provide a theoretical reference for the selection of GNSS-based passive radar radiation sources and the deployment of receiving stations.

Abstract:With the development of synchronization and high-performance computing technologies, the four advantages of bistatic/multi-static radar systems on anti-jamming, anti-destruction, anti-stealth targets, and anti-low-altitude target invasion have been gradually coming true. The bistatic/multi-static radar systems have attracted great attention. The bistatic scattering characteristics on Radar Cross-Section(RCS),scattering center,and polarization are quite different from the monostatic radar. Only baed on the detailed understanding of bistatic scattering characteristics, ?the bistatic/multi-static radar potentials in target detection,feature extraction,and target recognition can be fully exploited. The issue of bistatic scattering characteristics is one of the urgent problems waiting to be investigated. This paper reviews the newest development of bistatic scattering characteristics and attempts to guide future research on bistatic radar.

Abstract:Netted radar data fusion processing has the characteristics of wide application scenes, adopting diverse algorithms and using controllable parameters. Aiming at the problems of long development cycle and high system design complexity existing in the development of traditional fusion processing system, based on the component design of fusion processing, a general template of network fusion processing is designed by using open and reconfigurable architecture. Because of the low coupling of components, the system can be expanded easily only by modifying some components instead of building a whole system. The expanded contents include new component algorithms and new fusion templates. Compared with reconstructing the whole system, the independent and easy-to-understand component expansion operation reduces the complexity of the system and the ability requirements for developers. Simulation experiments have achieved two types of expansion. The results show that the design is feasible, improves the integration efficiency of the new algorithm, and enhances the scene adaptability of the networked fusion processing system.

Abstract:In order to improve the efficiency of radar system simulation, a component-based method for constructing signal processing module of radar simulation system is proposed in this paper. Firstly, a library of signal processing function components is established based on the independence of the different functions of radar signal processing for the proposed method; on this basis, the required signal processing modules can be flexibly constructed by selecting and splicing components after analyzing the simulated radar; finally, the effectiveness of the proposed method is demonstrated by the experiment through the radar componentized signal processing module constructed in Visual Studio 2013 platform.

Abstract:There are many problems faced by cognitive Electronic Warfare (EW) equipment, including complex and diverse combat scenes, being difficult to obtain real data and high cost of actual combat training. In order to meet the needs of scheme demonstration and key technology research, by combining artificial intelligence with system simulation technology, the signal level model of cognitive EW equipment and its typical combat objects is established. The information interaction process between EW equipment and combat objects in complex electromagnetic environment is simulated. A learning training and simulation evaluation system for future battlefield cognitive confrontation is built. The function, architecture, workflow and key modules/models of the system are introduced in detail. The application examples of the system are analyzed. According to the application effect, the system can provide guidance for intelligent algorithm model training of cognitive EW and the simulation test evaluation on equipment combat capability.

Abstract:In order to improve the reality of false-target image in deception jamming against Inverse Synthetic Aperture Radar(ISAR), the signal modeling of two-dimensional decoys in Self-Screening Jamming(SSJ) scenarios with controllable position is studied based on the modulation template in scattering center model. Firstly, the time delay in the fast time domain corresponding to the longitudinal modulated coordinates and offsets can control the position of the false target in the down range. Secondly, the phase modulating coefficient in the slow time domain corresponding to the transverse modulated coordinates and offsets can control the position in the cross range. Thirdly, the modulated speed would cause horizontal extension or compression of the false-target image. The simulation results verify the correctness of the theoretical analysis and demonstrate the effectiveness of the proposed jamming method, and it also has low power requirement.

Abstract:There are contradictions between similarity and particularity when simulating the signal and data processing of different radar systems. Based on the component design, radar signal and data processing are divided into 28 components including antenna simulation, target echo power calculation, pulse compression, parameter measurement, trajectory start, tracking filter, scheduling strategy and so on. By choosing the parameter of radar type, the particularity radar function can be simulated. Meanwhile, the components of similarity radar function are reusable so that the phased array radar, mechanical scanning radar and passive radar are simulated in functional level. The components are tested to verify the effectiveness of the component design method.

Abstract:Huynen Target Parameters(HTPs) and Optimum Polarizations(OPs) are two fundamental concepts in the polarization information processing field. According to the characteristic angle of HTPs, the graphical representation of OPs can be divided into three classes, needle shape, top shape, and the well-known fork shape, which has not been sufficiently discussed before. In this paper, OPs are derived based on the Kennaugh matrix. Then, the relationship between HTPs and OPs is revealed. On the basis of that, the polarization scattering characteristics of several typical structures are investigated. This paper aims to establish a clear concept about HTPs and OPs for radar polarimetry researchers.

Abstract:Terahertz (THz) wireless communication technology is one of the potential key technologies of the future 6G. It has aroused extensive attention at home and abroad. Firstly,the research plans and trends of 6G are introduced, and the features and advantages of THz wireless communication are reviewed. Then prospective scenarios as well as challenges of THz wireless communication applied in the future 6G are described. At last, action proposal towards 6G is suggested.

Abstract:A design method and experimental results of the low loss terahertz cavity used in terahertz molecular clock are introduced. Physical simulation design and structure design of terahertz cavity are carried out by CST. Through simulation and optimization, the miniaturized terahertz cavity structure with the reflection coefficient S₁₁ less than -10 dB is designed in the range of 230 GHz±10 GHz. The fabrication of terahertz cavity is completed by using the existing processing technology. The reflection of the cavity in G band is less than -10 dB and the transmission loss is less than -5 dB, which lays the foundation for the development of terahertz molecular clock.

Abstract:A forward modeling method is proposed based on attribute scattering center for target time domain echo simulation in order to quickly obtain the electromagnetic response of the radar target in the time domain under the excitation of Ultra-Wideband(UWB) electromagnetic pulses. Starting directly from the target geometric model, ray tracing and diversity techniques are adopted to mark and classify all rays in space, the strong scattering source of the target is separated and quantitatively characterized. Based on the form of the attribute scattering center model, the model parameters are positively determined, the target attribute scattering center model is constructed, and the simulation calculation is performed under the excitation of the selected radiation source to quickly obtain the target time-domain echo signal. Taking a typical target simplified tank as an example, different types of UWB electromagnetic pulse signals are selected as the radiation source, and a simplified tank scattering center model is constructed based on the forward modeling method to quickly obtain radar echo signals under the excitation of a given electromagnetic pulse. Compared with the one-dimensional distance profile obtained by the high-frequency simulation method, the results of the proposed method have good consistency, which verifies the effectiveness of using the scattering center model to quickly perform echo simulation under the excitation of different radiation sources.

Abstract:The high gain converter based on coupled inductance has a good application prospect in both new energy generation and DC microgrid. The operating principle of high gain Buck-Boost converter based on coupled inductance is analyzed, the switching flow diagram method is adopted to establish the converter model, and the steady state model and AC small signal model are derived in detail. The simulation results of Power SIMulation(PSIM) software on the converter small signal model prove the correctness of the proposed model. The results of this paper have high reference value for the design of control circuit of high gain DC/DC converter.

Abstract:Aiming at the contradiction between security requirements and resource consumption of wireless network nodes, a wireless sensor network node optimization game model is proposed based on game theory. Firstly, by analyzing the attack cost of the attacker and the defense cost of the defender in the network node, the utility function of the offense and defense is analyzed based on game theory, and the offense and defense game model is constructed. Secondly, according to the different action strategies selected by the offensive and defensive parties in the network node, combined with information theory technology, the offensive and defensive parties are abstracted into random variables, and the game channel model is designed. Then, the attack cost of the attacker and the defense cost of the defender are analyzed according to the channel capacity and Nash equilibrium fusion theorem. When the utility of both parties in the game reaches the Nash equilibrium, it is equal to the channel capacity. At this time, the action strategy adopted by both parties is the Nash equilibrium solution of the game. Finally, through experiments and simulations on the designed model, the results show that the model effectively reduces the defense overhead of the network system and prolongs the life cycle of the network system while ensuring the security of the wireless transmission network.

Abstract:A power Control-based Joint optimal for Throughput and Coverage(CJTC) algorithm is proposed in order to balance the conflict between system throughput maximization and coverage optimization in 5G Heterogeneous Ultra-Dense Networks(HUDN). Firstly, the objective function of throughput maximization is derived, and the transmission power of the base station to achieve throughput maximization is solved by convex optimal equation conversion. Then, the objective function of coverage optimization with minimum switching failure rate is derived, and the optimal transmission power of the base station is obtained by iterative joint solution with extension technique. Experimental results show that the proposed CJTC algorithm is superior to other CJTC algorithms in throughput and coverage.