Abstract:

As electronic technology advances towards higher integration and miniaturization, three-dimensional circuit layouts have become increasingly prevalent, making the effective transmission of millimeter-wave signals between the surface and internal circuits particularly critical. This study presents a novel design for an ultra-wideband, low-loss vertical interconnect structure transitioning from a stripline to a Grounded Coplanar Waveguide(GCPW), aimimg at addressing signal reflection and radiation issues caused by parasitic inductance and capacitance in interconnect structures. Through the analysis of an equivalent circuit model and preliminary parameter design, combined with optimization using three-dimensional field simulation, the final design parameters were determined. The interconnect structure employs a 0.2 mm diameter via for connection and features an isolation ring with a mere 0.8 mm diameter, ensuring the simplicity and ease of fabrication of the structure. Simulation results indicate that the design achieves broadband coverage from DC to 80 GHz, with S₁₁ less than -13 dB and S₂₁ greater than -0.4 dB, demonstrating excellent performance. To interface with the testing system, a test board was designed to convert to a coaxial connector, extending the operating frequency to 40 GHz. Actual test results show that, within the DC to 40 GHz range, return loss is less than 11 dB and insertion loss is less than 0.4 dB, further verifying the effectiveness and practicality of the design.

Abstract:

Single-pixel imaging is a novel computational imaging technique that uses only a single-pixel detector to acquire the image of an object with the help of spatial light modulation. In the terahertz band, to overcome the problem of scarcity of array detectors and realize sub-wavelength imaging in near-field modulation, a continuous terahertz single-pixel subwavelength imaging system is presented based on an optically pumped silicon wafer all optical modulator with a spatial resolution of λ/7.62. The imaging results on the resolution test chart show that when the imaging details are not of particular interest, thick silicon wafers can be employed to obtain large modulation depths, and the compressive reconstruction algorithm can be adopted to suppress noise and smooth the output images. To pursue higher imaging spatial resolution, thin silicon wafers are needed to reduce the crosstalk between modulation units, and the correlation reconstruction algorithm is employed to retain more image details. This study provides a concise reference for terahertz subwavelength imaging.

Abstract:

Terahertz photothermoelectric detectors are based on the principle of thermogenerated carriers migrating under the influence of a temperature gradient to achieve terahertz wave detection. They have advantages such as fast response, ultra-wideband, self-powered, room temperature operation, and simple structure, which have attracted widespread attention. Currently, the readout of detectors mainly adopts a modulation-demodulation method, realized by cascading a current amplifier with a lock-in amplifier for measurement, which has low integration, high cost, and is difficult to achieve array readout. To meet the application requirements of spectral measurement and imaging perception, this paper studies the readout method of the photothermoelectric array detector unit. Starting from the detector mechanism, the output signal is modeled and analyzed; based on this, a board-level dedicated readout circuit is designed to achieve front-end amplification and lock-in amplification functions. Tests show that this method can achieve high-precision readout of terahertz photothermoelectric detectors in a strong noise background environment, with a gain of 140.7 dB, and the signal-to-noise ratio is improved by 38.3 dB.

Abstract:

Metasurfaces are artificial surfaces composed of sub-wavelength unit structures, demonstrating tremendous potential for manipulating electromagnetic waves. Catenary electromagnetics provides new ideas and methods for the design of metasurfaces. This paper proposes a multifunctional dichroic metasurface based on a catenary structure, capable of selectively absorbing electromagnetic waves in different directions. Simulation results show that the device can achieve 92% Linear Dichroism (LD) and 96% Circular Dichroism(CD) in the infrared region. Both functions can be realized simultaneously by merely changing the incident direction of the electromagnetic waves, and both functions have high efficiency within a certain range of incident angles. In addition, the influence of different geometric parameters on the absorption performance is analyzed, as well as the physical mechanisms for selective absorption of different electromagnetic waves. This metasurface has the advantages of simple structure, easy integration, and a wide range of applications, and has potential application prospects in the fields of imaging, sensing, and spectroscopy.

Abstract:

Based on a flexible twisted bilayer chiral metasurface sensor, utilizing terahertz time-domain spectroscopy technology, with chiral Lactic Acid(LA) enantiomers as the research subjects, a method for sensing the concentration of chiral substances and enantiomer recognition in the terahertz band is proposed. The results show that the Transmission Circular Dichroism(TCD) of the chiral metasurface sensor shifts with the increase of concentration, and the shift amounts are different for different chiral enantiomers. The highest detection sensitivity for Levorotatory Lactic Acid(L-LA) and Dextrorotatory Lactic Acid(D-LA) are 2.6 GHz/(mg/mL) and 1.9 GHz/(mg/mL), respectively, with a detection limit as low as 0.01 mg/mL. The great potential of the chiral metasurface sensor in LA sensing and chiral recognition provides an efficient, low-cost technical method for the sensitive detection of chiral enantiomers.

Abstract:

A pixel-level digital focal plane readout circuit was designed to overcome the charge capacity limitations of traditional analog readout circuit technology, enabling a larger dynamic range and lower noise digital image readout. Additionally, digital image processing is performed internally at the pixel level, enabling functions such as Non-Uniformity Correction(NUC), dead pixel compensation, digital Time-Delay Integration(TDI), and spatial filtering for image preprocessing. The circuit was fabricated using a 40 nm CMOS process with an array specification of 640×512, a pixel pitch of 30 μm, and the overall chip size is approximately 22 mm×19 mm. Test results indicate that the circuit can significantly reduce(by approximately 90% and 63%, respectively) the spatial noise in the output image through TDI and spatial filtering functions, thereby enhancing the image quality.

Abstract:

High-performance wide-spectrum upconversion imaging devices play an important role in fields such as medical care, food safety, non-destructive testing, and national security. However, existing semiconductor upconversion devices are limited by their narrow detection range and low upconversion efficiency. In order to achieve a wider spectrum and efficient upconversion, this study significantly improves the performance of the ratchet upconversion device by optimizing the LED structure. The improved LED's electroluminescence efficiency has been increased by two orders of magnitude. It can turn on light at a driving current of μA level, and its electroluminescence spectrum is closer to the theoretical regular Lorentz line. The overall surface luminescence uniformity of the device is also significantly improved. The research clarifies the performance optimization principles and provides a reference for future improvements in upconversion devices.

Abstract:

Based on the fundamental principles of quasi-optical and Gaussian beams, research has been conducted on quasi-optical reflectors and lenses, leading to the design of a quasi-optical feed system for millimeter-wave and submillimeter-wave antennas. This system is capable of simultaneously receiving electromagnetic radiation signals in the 89~115 GHz and 176~183 GHz frequency bands through two optical paths. Elliptical reflectors and lenses are utilized to focus the beams and control the system's structural envelope. Polarization grid networks are employed to separate channels, and calculations and preliminary analysis of dual-channel performance are conducted. The system operates in a low-temperature environment, and in response to practical requirements and cold optical analysis, constraints are proposed and optimized for the spatial position and beam radius of quasi-optical components. Theoretical calculations and simulation results indicate that the system meets the design requirements for cold optics and quasi-optics.

Abstract:

In response to the current intelligent anti-jamming technology's poor performance against rapidly changing interference, a new type of intelligent anti-jamming technology combined with priori knowledge networks is proposed. Firstly, a priori knowledge network is constructed to predict the interference information of the next moment based on historical interference information, enabling the system to better cope with rapidly changing interference; then, reinforcement learning algorithms are employed to achieve online learning of new interference patterns, allowing the algorithm to be applicable to scenarios where the dynamic changes of interference exceed the adaptation range of offline learning models. The simulation comparison between the proposed algorithm and the reinforcement learning algorithm without prior knowledge shows that the proposed algorithm has higher decision accuracy and faster convergence speed when facing rapidly changing interference, and has better adaptability to the environment, which can effectively carry out intelligent anti-jamming.

Abstract:

Aiming at the problem of jamming suppression in distributed radars, a joint polarization-spatial-temporal domain processing method is proposed for compound jamming in distributed radars. Firstly, a distributed polarization array radar system model of single-transmitter multiple-receiver is established. Secondly, the received signal is reconstructed into a third-order tensor according to its polarization-spatial-temporal characteristics. Furthermore, tensor decomposition is employed to separate the target echo from jamming signals, so as to realize the suppression of blanket jamming and smart jamming. Then, by using the uniqueness of the position and velocity information of the real target, the deception jamming is suppressed by joint positioning of multiple sites, while the position coordinates and velocity vectors of the target are estimated in the meantime. Finally, the effectiveness of the proposed algorithm is verified by numerical simulation experiments.

Abstract:

Under the influence of earth curvature, the localization error of traditional positioning model based on rectangular plane coordinate system will increase significantly with the detection range increasing, and it seriously affects the positioning and tracking accuracy of long-range targets. This paper proposes a positioning method with single moving platform based on spherical models. It transforms the plane rectangular function equation into the spherical trigonometric function equation to reduce the influence of the earth curvature error. It utilizes the Unscented Kalman Filter(UKF) algorithm to solve the complicated nonlinear observation equation iteratively and realizes high-precision position estimation of long-range targets. Simulation results demonstrate that the proposed method based on spherical models has a higher position accuracy which is increased by 0.3%R~0.6%R.

Abstract:

For the application of the Multiple Signal Classification (MUSIC) algorithm with super-resolution capabilities in the direction finding of passive radar seeker heads based on conformal polarization-sensitive arrays, the definition of spectral function angular resolution and the discrimination angle threshold are proposed. By approximating the expected value under the asymptotically biased condition using the definition of the MUSIC algorithm's zero spectrum, the corresponding angular resolution expressions for vector array and scalar array models are derived respectively. Taking the uniform circular array as an example, the influence of various parameters on angular resolution is quantitatively analyzed based on the computer simulation model, and the statistical values of the discrimination angle threshold for scalar and vector arrays are compared. Simulation results show that under the same array and signal source parameter settings, the discrimination angle value of the scalar uniform circular array is generally higher than that of the vector uniform circular array.

Abstract:

In recent years, thanks to the enhancement of computing power of computers and the vast amount of data generated by the internet, Deep Learning(DL) technology has achieved rapid development. Among them, the most notable Convolutional Neural Networks(CNN) have successfully been commercialized in fields such as image recognition,object detection, and natural language processing. However, as the network layers become deeper, the demand for computing power and memory has risen sharply. How to accelerate convolutional neural networks and deploy them on hardware accelerators has gradually become a hot topic in academic research. Starting from the advantages of developing neural networks with Field-Programmable Gate Arrays(FPGA), various development methods of FPGA are introduced, various optimization strategies for deploying and accelerating convolutional neural networks are discussed in detail, and the performance of FPGA convolutional neural network accelerators using different optimization strategies is presented. Finally, the future development direction of FPGA convolutional neural network accelerators is expected.

Abstract:

In view of the problems of long data migration, high maximum occupancy rate of storage space, high error rate of transfer learning and low online probability of visited data, the historical data migration technology of domestic database based on domestic Central Processing Unit(CPU) environment is studied. Firstly, the system software and hardware are clustered and deployed in the domestic CPU environment to improve the migration rate of historical data between domestic databases. Secondly, an isolation forest model is established, and the historical data is input into the isolation forest model for trend prediction, thereby eliminating the abnormal data in the domestic database, and reducing the amount of data to be migrated. Finally, a data migration model is constructed, and an alternating optimization strategy is adopted to find the optimal solution of the model, thus completing the migration of historical data in domestic databases. The experimental results show that the data migration time of this method is 18 minutes, and the maximum occupancy rate of storage space is between 10% and 25%, the ALC(Area under the Learning Curve) index value is 0.78~0.95, and the online probability of the accessed data can always be maintained at more than 97%, proving that this method has a short data migration time, a low maximum occupancy rate of storage space, a low error rate of migration learning, and high access efficiency, demonstrating good application effects.

Abstract:

A low-g-value magnetic self-locking Micro-Electro-Mechanical Systems(MEMS) inertial switch with a threshold of 5g, featuring adjustable threshold and self-recovery capabilities, has been designed. The inertia sensitive unit of this inertial switch consists of a square mass block, a square chessboard-shaped magnet fixed beneath the mass block, and four square Archimedean spiral beams supporting it. The magnet, along with four ferromagnetic fixed electrodes located beneath the moving electrodes and a double-layer planar coil, jointly achieve the functions of magnetic self-locking and threshold adjustment. Simulation analysis is conducted using the finite element simulation software ANSYS. The prototype is manufactured by using laser processing and PCB technology, and the performance of the sample is tested by using a centrifuge. The test results show that the fabricated MEMS inertial switch has a threshold acceleration of 5.27g in the vertical sensitive direction. By applying a current in the range of -0.5 to 0.5 A, the threshold adjustment range is from 6g to 3.75g. The results indicate that this structure can achieve the locking function while enabling self-recovery without external force and allowing threshold adjustment within a certain range.

Abstract:

To obtain the high-voltage high-repetition-rate pulse output with a half-width of about 10 ns required for plasma research, two sets of high-voltage switch modules composed of Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) switches in series are used. By combining traditional capacitor energy storage pulse generation circuits with pulse tail cutting circuits, narrow pulses are generated. Based on the actual working requirements of the switches, adaptive design and simulation optimization of the narrow pulse generation circuit are carried out; according to the optimization results, an experimental device for narrow pulse generation circuit is built. After testing, a pulse output with a peak voltage about 10 kV, a half-width about 10 ns, and a front edge about 6 ns is obtained on a load of 500 Ω.

Abstract:

Variations in space environment temperatures can have distinct effects on the level of charging on dielectric materials surfaces of spacecraft. To address this, a numerical model has been established in this paper based on the current balance equation to study the impact of temperature on the surface charging of polyimide. Subsequently, utilizing a spacecraft material surface charging simulation experiment system, the influence of temperature changes on the surface charging characteristics of polyimide under electron irradiation is investigated. The simulation results indicate that when the temperature is fixed, the surface charging equilibrium potential of polyimide increases as the beam current density increases at levels of 0.5 nA/cm², 1 nA/cm², and 2 nA/cm². Conversely, when the beam current density is held constant, the surface charging equilibrium potential of polyimide decreases with the rise in temperature within the range of 243 K to 363 K. The larger the beam current density, the less significant the effect of temperature changes on the equilibrium potential. This research finding can serve as a reference for the charging protection of dielectric materials on spacecraft in response to temperature variations.

Abstract:

Effective choice of the solution is essential to achieve a real-time, bi-directional(full- duplex) communication of the smart grid. The Power Line Carrier(PLC) technology provides a low-cost solution, which suits China's own national conditions. In this paper, the advantages of OFDM PLC modulation technology are introduced. A PLC module of system model is established through the analysis of the input impedance under the low-voltage power line channel. The high-speed PLC module based on low-voltage Power Line is also designed according to the studies of power line channel. The results show that the design of the PLC module has featured high receiving sensitivity and anti-noise ability.

Abstract:

With the development of Internet applications, users’ demand for bandwidth is soaring sharply. Meanwhile，along with the development of broadband access technology, the endpoint can also adopt multiple network accesses. But due to one-way communication of traditional Transmission Control Protocol(TCP)，the waste of resources will exist. To this end，IETF has specifically proposed Multi-Path TCP(MPTCP) to implement TCP multiplexing，thereby enhancing the efficiency and robustness. This paper gives a review of the IETF’s research on MPTCP，including MPTCP architecture, routing and congestion control, aiming to provide a reference for deeply studying.

Abstract:

Traditional methods and instruments are not able to measure the true Root Mean Square(RMS) of distortion sine wave or non-sine signal accurately. This article introduces a method to measure the true RMS of any high frequency signal by using the true RMS measurement IC，AD536A，designed by AD corporation. The paper analyses the difference between the RMS measured by the average measure method and the true RMS in theory. It explains the disadvantages of current RMS measure method，and presents the design of true RMS measure circuit. The experiment results prove that the proposed method and circuit can measure the true RMS of any high frequency signal accurately.

Abstract:

Terahertz(THz) optoelectronics has promoted the development of the THz generation, transparent control, and detection methods，and hastened many devices in the past decades. Especially, THz metamaterials and metasurfaces will exhibit extraordinary electromagnetic response when the subwavelength scale metal structure is excited by the THz illumination. Therefore, they have been applied to the devices such as wave beam shaper, waveguide, and modulator etc. The THz metamaterials and metasurfaces also show the potential applications in the research fields such as sensors, communications, and radars. In this paper, the works about the spectrum and wavefront modulation with THz metadevices carried out in our group are summarized. The basic theory and corresponding experiment results for different devices are introduced. It is expected these works can pave the avenue of the application of the THz metadevices.

Abstract:

Aiming at the problems in existing underground personnel positioning systems, an assisted positioning method based on pedestrian dead reckoning is proposed. Low-cost Inertial Measurement Unit(IMU) and magnetometer are employed to constitute a stable Attitude Heading Reference System (AHRS). The theory of inertial navigation is utilized, an algorithm for step detection is described, and Zero velocity Update(ZUPT) is adopted for velocity and position estimation to compose a pedestrian dead reckoning system. An experiment is performed in the corridor of a laboratory building to emulate the underground mine road environment. The experimental results demonstrate that the dead reckoning performs well and this method is an effective complement to existing underground positioning by improving the positioning accuracy.

Abstract:

The requirements for micro stress measurement of strain gauge are high precision，high linearity，high stability and high gain. One kind of differential amplifier circuit with excellent performance was designed. Some skillful techniques were adopted to avoid common voltage in the circuit and to reduce the temperature drift. The gain linearity is about 0.01%，and its Common-Mode Rejection Ratio(CMRR) is about 129 dB under work conditions.

Abstract:

According to the requirements of safe, simple and nondestructive radiation effect investigation of semiconductor devices, the method of laser simulation was proposed and greatly promoted. Compared with large-scale facilities, laser simulation has various unique advantages. It helps understand the ionization radiation effect in depth and is an effective low-cost, table-top supplement for the hardness assurance. Its research shows great significance for radiation effect study in both theory and practice. In this paper, the basic principles of the interactions of γ and laser with semiconductor devices are firstly presented. Then the physical basics and characteristics of laser simulation are given, with the research progress review followed. The existing problems of current research are deeply discussed providing with feasible research approaches. In the end, necessary research contents in the future are proposed.

Abstract:

The background requirements of the fuze antenna in terahertz spectrum as well as its advantages and disadvantages are introduced. The working principles and application characteristics of dielectric lens antenna in terahertz frequency are analyzed in order to implement the terahertz fuze antenna. The longitudinal size of H plane horn antenna can be reduced effectively by using fuze antenna formed by an H plane horn with dielectric lens antenna. The terahertz fuze antenna with different beam angles is achieved by focal technology of lens. The feasibility of the technology solution is verified through simulation.

Abstract:

Ultra-wideband(UWB) communication shows its advantages of fast data transfer(100 Mb/s or above) in a relatively short distance(typically below 10 m) with relatively weak power consumption (energy spectrum below -41.3 dBm/MHz). Integrated with Multiple Input Multiple Output(MIMO) technology, channel capacity could be further enhanced. As a critical link in the ultrawideband communication，UWB antenna needs extra efforts in design optimization to boost the performance of the whole system. UWB antenna is defined as the antenna whose bandwidth exceeds 500 MHz or relative bandwidth greater than 20%. This paper takes the most representative Vivaldi antenna as a show case for multi-objective optimization design with statistical methods. The optimized miniaturized antenna(sized130 mm×100 mm) shows a -10 dB bandwidth of 2.4 GHz. The design method provides guidance in common wideband，multi-parameter antenna design.

Abstract:

Radio Frequency IDentification(RFID) series Radio Frequency(RF) card has been applied widely because of its stability，reliability and easy operation features. Aiming at multiple protocols，such as ISO14443 protocol，ISO15693 protocol and Tag-it protocol，this study proposed a new type of circuit design based on Advanced RISC Machine(ARM) for the RFID series RF card reader. The data stream encryption was implemented by using peripheral device in the operation. The system composition，working principle and work flow were introduced. Then，the detailed circuit design of the RF network and encryption hardware were presented，and the test and analysis for the design were performed. The results showed that the circuit could accurately read, write and encrypt various types of card within effective range.

Abstract:

The design of code tracking loop is a key sector of the realization of noncoherent spectrum spread receiver. In order to realize the code tracking in noncoherent spectrum spread receiver, an energy-normalization digital delay-locked loop was designed, the structure of the loop and the calculating procedure of loop parameters were introduced. The characteristic of noncoherent spectrum spread was analyzed first，and then the key point of the loop design was pointed out. Based on this, the design and realization methods of code loop discriminator, loop filter, early and lag code generator were expatiated. A set of specific loop parameters were introduced as well. Modelsim simulation results and FPGA actual measured data prove the precise code tracking ability of the design.

Abstract:

The implementation of TCP/IP protocol stack on TM320DM642 platform could provide technological support for the application of multimedia embedded systems to networks. Both the function of TM320DM642 chip and the hierarchical structure of LWIP(Light Weight Internet Protocol) were analyzed. Network communications for TM320DM642 systems were implemented by the transplantation of LWIP, not by a solution scheme of NDK(Network Developer’s Kit). Testing examples verified the effectiveness of the LWIP transplanted method.

Abstract:

This article introduces a new type of high speed，multi-modulated digital modulator with adjustable center frequency and bit rate features. It can realize the Quadrature Phase Shift Keying(QPSK) and 16QAM(Quadrature Amplitude Modulation) with 80 MHz center frequency and 7.936 5 MHz bandwidth. The general-purpose modulation arithmetic based on software radio，symbol mapping and the realization of pulse shaping filter are discussed. The measuring results demonstrate that the modulation scheme meets the requirements of practicability and general utilization.

Abstract:

The application of CORDIC(COordinate Rotation DIgital Computing) arithmetic in solving transcendental function has become popular in modern engineering. A brief introduction of CORDIC arithmetic was given in this study. Taking the hyperbolic sine and cosine functions as examples, the method of realizing the arithmetic in FPGA was presented and simulated on ISE(Integrated Software Environment) platform. The result showed this arithmetic was of good precision and instantaneity because of using pipeline. This arithmetic has great practical value in some applications. In addition, a curve of the relationship between the iterative number and the error obtained by the Matlab simulation of the arithmetic can help designers planning the number of iterations for practical applications.

Abstract:

The Spatial Light Modulation(SLM) technology has been widely applied to the fields of threshold switch, high speed optical interconnection and optical logic operations, which demands good performance on the real-time and fast optical signal addressing. Compared with Electro-Addressing SLM(EA-SLM), Optically-Addressing SLM(OA-SLM) shows great advantages of fast speed and high resolution by parallel addressing. Nevertheless, how to achieve fast and stable optically addressing is the key point in practice. Based on ZnO thin film as a photoconductive layer, Liquid Crystal OASLM(LC-OASLM) is designed and fabricated; the modulation of the readout light intensity and phase distribution in the two-dimensional space is achieved effectively.

Abstract:

High-speed data acquisition system is an important component in modern radar signal processing. A design of high-speed data acquisition system based on band-pass sampling was presented and applied to the signal processing of wideband receiver. The Virtex Series FPGA was used as the main platform to control the high-speed ADC08D1000 for completing data acquisition, transmission，storage and signal processing. High-speed First Input First Output(FIFOs) were selected as the storage devices to implement data rate conversion. The system realized the software and hardware design，and test results verified the feasibility of the solution.

Abstract:

The corresponding solutions are proposed to tackle with the disadvantages of conventional oilfield Geographic Information System(GIS), including inconvenience of Client/Server(C/S) mode operation and maintenance, being unable to perform real-time online Point of Interest(POI) rendering, being incapable of segmentation and location according to regions, etc. An oilfield information query system of Browser/Serve(B/S) framework based on AJAX+JSON+HTML5 is designed and implemented. Experimental results show that the POI real-time rendering and regional segmentation improve on their interactivities, and the experiences of users are enriched, which meets the actual requirements of oilfield development. This work has paved the way for the development of diversified network services.

Abstract:

A detector can achieve quick response when it is much smaller than the wavelength of the source signal in THz wave band at the expense of signal coupling capability．Therefore, an antenna is applied to collect signals in order to enhance the signal coupling capability of the detector．The properties of antenna determine the frequency response band，the sensitivity and other parameters of the detector directly. A planar-integrated antenna is adopted for signal acquisition in the Nb5N6 microbolometer detector, which is fabricated by lithography，lift-off and other processes of micro-fabrication. The Nb5N6 microbolometer is placed in the center of the planar antenna. Aiming for the center frequency of 0.32 THz, a special capacitive coupling design is proposed to improve the signal coupling capability．

Abstract:

A double gate setting with priority of Doppler velocity and the Extended Kalman Filter(EKF) based Multiple Hypothesis Tracking(MHT) algorithm are proposed in order to realize Multiple Targets Tracking(MTT) in High Frequency(HF) ground-wave radar, and to effectively improve the performance of MTT by using the Doppler measurement. In the EKF based MHT, parameters obtained in the EKF are adopted directly to calculate the probability of each hypothesis. A simulation scene is built, and the EKF based MHT algorithm is compared with the one which assumes that the Doppler measurement is independent from the radius measurement. Simulation results show that the double gate setting helps induce number of clutter, and the EKF-based MHT algorithm is better than the other one under dense environments of HF ground-wave radar with stronger track-catching and false-alarm-filtering ability and higher efficiency.

Abstract:

The single-channel blind separation of GMSK(Gaussian Minimum Shift Keying) mixing signals is researched. The GMSK mixing signals can not be separated by the Per-Survivor Processing (PSP) algorithm directly, therefore, linear approximation processing of the GMSK signal is considered, which enables GMSK signal to be separated by the PSP algorithm. This algorithm separates the GMSK mixing signals by maximum likelihood estimation in the joint space of the symbol sequential and the channel parameters, reserves the best path and outputs the symbol pairs to get the separated signals. Simulation results show that the bit error rate performance produced by the PSP algorithm on separating the GMSK mixing signals is slightly better than that produced by the particle filtering algorithm; and the complexity of the proposed PSP algorithm is much smaller.

Abstract:

A new usage of Hough Transform is introduced in this paper.Firstly,the position and scope of the license plate is located and the image that contains the license plate is picked up.Then, a two-stage Hough transform algorithm is applied to the image to cal

Abstract:

A forward secure strong proxy signature scheme is proposed on the basis of the proxy signature schemes and forward secure schemes.The security of the proposed scheme relies on the difficulty of solving discrete logarithm problems and the difficulty of com

Abstract:

Based on three generally accepted basic hypotheses, the definition of environmental factor and restricting conditions of constant failure mechanism are discussed.The research status and common study methods of environmental factor are reviewed. Finally, a

Abstract:

For completing the scheme of hard target smart fuze, several factors influencing the outputting acceleration of the high-G accelerometer such as target material, impact angle, impact velocity, the fixed position of accelerometer, carry plane etc., are put

Abstract:

Blind source separation (BSS) is a recently developed methodology used to separate unknown source signals from their mixtures. It has been applied to many fields widely and effectively. The theory and two types of implementation methods-independent compon