Abstract:

In recent years, the rapid development of smart terminals and wireless networks has led to an exponential growth in the number of terminal devices and data volumes in the power IoT. These data resources have become important assets for power enterprises, significantly enhancing the smart sensing,internal control capabilities, and customer service efficiency of the power grid. However, as critical national infrastructure, power data is vulnerable to cyber-attacks and theft. If leaked, it could cause significant security risks and economic losses. Therefore, power enterprises must strengthen data security protection to address the security issues in data exchange, sharing, and mining. A cloud-edge collaborative intelligent grid data security sharing scheme is proposed, combining zero-knowledge proof technology with a secret sharing scheme to achieve fine-grained access control and privacy protection for user access requests. Finally, the simulation results show that the total time required to perform distributed data access verification in this paper is no more than 48 ms, indicating that the algorithm has a good performance.

Abstract:

Low-Earth Orbit(LEO) satellites have the characteristic of global coverage. The Long Range(LoRa) network based on LEO satellite Internet of Things(IoT) has become a research hotspot. To address the floor effect issue of LoRa modulation schemes in LEO satellite channels, two differential LoRa demodulation strategies are proposed for the differential LoRa modulation scheme. Firstly, a closed-form expression for the Symbol Error Rate(SER) is derived under the LEO satellite channel with dynamic Doppler frequency shift, illustrating the floor effect issue of LoRa modulation in LEO satellite channels. Subsequently, the derived closed-form SER expression is validated using Monte Carlo simulations, and the Bit Error Rate(BER) performance of LoRa modulation and the proposed differential LoRa modulation is evaluated. Simulation results show that compared with the LoRa modulation scheme, differential LoRa modulation and the proposed differential LoRa demodulation strategies can effectively improve the BER performance of LEO satellite IoT under dynamic Doppler frequency offset scenarios.

Abstract:

With the vigorous construction of the digital new power system, the traditional power communication network is gradually transforming into a more robust, resilient, and multi-service-bearing all-time and all-domain communication network.To address the issue of difficult-to-guarantee deterministic latency for time-sensitive services due to the simultaneous access of multiple types of terminal services and massive data transmission in the all-time and all-domain communication network, a deterministic latency guarantee technology is proposed for all-time and all-domain communication networks based on Time-Sensitive Networking(TSN).Firstly, based on the analysis of the characteristics, importance, periodicity, and latency requirements of various types of services in the all-time and all-domain power communication network, the corresponding service models are established and prioritized. Then, a traffic scheduling mechanism based on TSN perception and shaping is proposed to ensure that the calculation of the gate control schedule meets the deterministic low-latency transmission of time-sensitive flows within the transmission cycle. To achieve the goal of minimizing end-to-end latency, a combined algorithm based on genetic algorithm and tabu search algorithm is employed to calculate the gate control list of time-sensitive flows. The average end-to-end latency is reduced by 15% compared with single optimization algorithm, and the latency jitter of time-sensitive flows is controlled at about 2 μs. This improves the scheduling performance and provides strong support for the stable and safe operation of the all-time and all-domain power communication network.

Abstract:

In the downlink collaborative transmission process of the power Internet of Things(IoT), it is necessary to optimize the effective capacity of the system while ensuring low-latency communication, in order to continuously provide high-quality services to users. A Quality of Service(QoS)-Guaranteed strategy is proposed based on Remote Radio Heads(RRH) Collaboration(QG-RRHC). A two-layer power IoT network model based on Orthogonal Frequency Division Multiple Access(OFDMA) is designed. By introducing the theory of effective capacity, a distributed RRH collaborative transmission scheme for QoS guarantee is studied, which collaboratively serves the downlink data transmission on different subcarriers. Additionally, a heuristic optimization algorithm based on Lagrange duality is proposed to solve the joint optimization problem. Simulation results demonstrate that compared with other benchmark algorithms, the proposed strategy can significantly enhance the system's effective capacity and achieve the performance close to the optimal.

Abstract:

With the continuous expansion and increasing complexity of modern power grids, there is a need for a technology that can integrate and process multi-source information to meet the demands of large-scale and highly complex information processing. This is essential to enhance the efficiency and security of power grid operations. To this end, a multi-source information fusion method for power grid operation based on fuzzy sets is designed. The collection of multi-source information for power grid operation is implemented through various sensors, including electric sensors, pressure sensors, and humidity sensors. The data collection methods of these sensors inevitably introduce noise into the collected data. To address this, wavelet denoising methods are employed to reduce noise and extract effective information from the power grid operation data. A multi-source information fusion method combining the fuzzy similarity matrix in fuzzy set theory and the Dempster-Shafer(D-S) evidence theory is designed to achieve the fusion of multi-source information in power grid operation. Experimental test results indicate that as the number of data types increases, the maximum confidence level of this method is in a growth phase. The maximum confidence level of multi-source information fusion reaches 0.94, demonstrating that the fusion results are reliable and applicable to the fusion of various types of data. After adding noise levels of 5 dB, 10 dB, 15 dB, 20 dB, and 25 dB, the maximum confidence level of multi-source information fusion using the designed method only experiences a minimal decrease. This indicates that the method has good robustness in multi-source information fusion. Additionally, the high information entropy values suggest that the fused information is richer in content.

Abstract:

With the large-scale development of renewable energy and the high proportion of massive terminals connected to the grid, the network load in the next generation smart grid will be further intensified, which brings unprecedented and great challenges to the power sensing network for real-time data collection and processing, and whole-domain information monitoring. At the same time, the sensor nodes have the problems of difficult energy replenishment as well as limited computational resources, and the traditional network structure will be difficult to meet the needs of the next generation grid, so it is of practical significance to study how to improve the energy efficiency of power sensor network. A Mobile Edge Computing(MEC) assisted computing offloading scheme for power sensor network is proposed to optimize the nodes' task processing latency and energy consumption under limited computational resources, by modeling the optimization problem as a Markov Decision Process(MDP) and solving the problem using Double Deep Q Network(DDQN) algorithm to minimize the total system overhead. Simulation results show that the proposed scheme outperforms the benchmark scheme in terms of delay, energy consumption and convergence performance.

Abstract:

With the rapid development of the energy Internet, new power services such as vehicle-network interaction have increasingly stringent requirements on service quality, which brings many challenges to the power terminal access network. To address the problem of resource waste and network performance degradation caused by the overlapping coverage of multiple communication technologies and a wide range of communication methods in terminal access network, a Communication Method Selection algorithm based on Random Forest(RF-CMS) is proposed, which intelligently categorizes a large number of diverse new electric power services and selects the most suitable communication methods for them through Random Forest mode. Then, the Multi-Agent Proximal Policy Optimization(MAPPO) algorithm is employed to dynamically allocate routes for the power services from the viewpoint of traffic loading and communication quality to ensure that various terminal service data (e. g., measurement information, control information) can be transmitted timely and accurately in the access network. The effectiveness of the proposed algorithm is validated by comparing it with the routing algorithm based solely on MAPPO in terms of average end-to-end delay and load balancing degree.

Abstract:

With the rapid development of Internet of Things(IoT), big data, and Artificial Intelligence(AI) technologies, massive amounts of data are being generated and utilized on an unprecedented scale. These data contain a large amount of sensitive information, and how to securely store sensitive data has become a realistic problem that needs to be solved. The existing data storage schemes usually focus on the direct protection of sensitive data, while ignoring the leakage risks associated with explicit and implicit associations between sensitive and non-sensitive data. The explicit and implicit relationships among data are deeply analyzed from the perspective of information entropy, and a method is proposed to quickly assess the explicit and implicit relationships and predict the leakage risk of sensitive data. By introducing the information Lift Ratio(LR) and the Probability of Information Control(PIC), the method can effectively identify the influence of non-sensitive data on the risk of sensitive data leakage. In the simulation experiments, the maximum single-attribute LR in the Statistical Property Dataset(SPD) is 0.308, and the joint-attribute LR can be up to 0.891, and the predicted value of the sensitive data leakage risk is significantly improved, up to 23.2%. The simulation results show that the method can effectively identify and cope with the security risks caused by explicit and implicit relationships, thus significantly improving the overall security level of sensitive data storage.

Abstract:

To conduct ultrafast application experiments such as terahertz-laser pump-probe experiments on the Terahertz Free Electron Laser Facility(THz-FEL), it is necessary to achieve high-precision synchronization at the femtosecond level between terahertz pulses and laser pulses. A technical method is proposed based on photoelectric detection and fast feedback from piezoelectric ceramics. Terahertz pulses are generated using the organic crystal N-Benzyl-2-methyl-4-nitroaniline(BNA), and the random jitter of the free electron laser pulses is simulated using an electrically controlled displacement stage. The piezoelectric fast feedback compensation system rapidly adjusts the optical path of the laser to reduce the jitter range, achieving high-precision real-time following of the terahertz pulses by the laser pulses.

Abstract:

There is a significant difference between the terahertz frequency and low frequency in the polarization scattering characteristics of targets. Taking dihedral angle as the research object, the influence of different surface roughness on the identification of target scattering structure and the integrity of profile is studied. Firstly, the rough model is geometrically constructed based on the linear filtering method. Then, the component interpretation is performed on the polarization image by Pauli polarization decomposition, and the integrity of target contour in radar image is quantitatively analyzed. Finally, the electromagnetic simulation results prove that the even component of dihedral angle decreases and the odd component increases with the increase of roughness, and the integrity of target profile is higher in radar image. Results show that the fusion of polarization interpretation and optical interpretation is an important approach for target recognition at terahertz frequencies.

Abstract:

In order to expand the application field of compact High Frequency Ground Wave Radar (HFGWR), research has been conducted on the scenario of single-station compact HFGWR detecting aircraft targets. By exploring the impact of high-speed targets on the range spectrum and Doppler spectrum, as well as the challenges faced in obtaining the speed and range information of high-speed targets, the constraints of the linear Frequency Modulated Interrupted Continuous Wave(FMICW) waveform parameter design have been derived. Corresponding waveform parameters have been designed for long and short coherent accumulation time, and numerical simulations have been carried out. The research shows that under the condition of long accumulation time, the Generalized Radon Fourier Transform(GRFT) method is employed to eliminate the migration of range and Doppler frequency,achieving effective accumulation of target energy and accurate estimation of motion parameters; under the condition of short accumulation time, the signal-to-noise ratio of the target is significantly improved by combining time-frequency analysis with the greedy algorithm to first estimate the motion parameters of the target, and then compensate for the slow time signal of the range.The feasibility of single-station compact HFGWR detecting high-speed targets has been verified through theoretical derivation and numerical simulation, and a theoretical foundation has been laid for subsequent field tests.

Abstract:

Based on the new threats posed by Artificial Intelligence(AI) to electromagnetic spectrum security and the current development status and trends of anti-jamming satellite communication systems, an intelligent anti-jamming satellite communication system architecture based on AI is proposed, which features 'distributed perception+hierarchical decision-making+unified action+quasi-real-time assessment'. The corresponding unit composition architecture of the satellite payload, terminals, and ground stations, and the hardware and software architecture required for engineering implementation are introduced as well in order to adapt to the increasingly intelligent interference situation. In light of the characteristics of extensive use of deep neural networks in the proposed intelligent anti-jamming satellite communication system architecture, the working mechanism of the system architecture is studied, the basic workflow and preliminary deployment methods are put forward. The relevant supporting technologies are analyzed and sorted out, the disadvantages of traditional technologies in areas such as interference perception, anti-jamming decision-making, anti-jamming waveform reconstruction, and quasi-real-time anti-jamming effectiveness assessment, are discussed. The current research status based on AI technology and the key issues that need to be focused on and resolved in the future are concluded. This is intended to provide some reference for the construction of AI-based anti-jamming satellite communication systems.

Abstract:

In response to the application requirements of drone communication systems, a novel metamaterial antenna is designed. This antenna employs periodic metamaterial unit cells as the radiating structure, achieving excellent performance such as broadband and high directivity through efficient manipulation of electromagnetic waves. The antenna consists of a 3×3 rectangular metamaterial array as the radiating element, fabricated using 0.15 mm thick copper foil attached to a 7.8 mm thick polymethylmethacrylimide(PMI) foam substrate. A coplanar waveguide with a coupled aperture feeding structure is utilized to reduce the antenna profile. The antenna measures 188 mm ×111 mm×7.8 mm, with a profile height of 0.034λ_L (where λ_L is the wavelength corresponding to the lowest operating frequency), and weighs only 52 g. It is mounted within an aluminum housing. Simulation and test results indicate that the antenna has a Voltage Standing Wave Ratio(VSWR) of less than 2, an impedance bandwidth of 28.4%(1.30~1.73 GHz), and a gain of 8.1~10.0 dBi within the operating frequency band.

Abstract:

With the rapid development of miniaturized implantable Radio-Frequency(RF) antennas, wireless sensing technologies for human body monitoring have ushered in new opportunities for development. Based on the structure of dental implants, a Dielectric Resonator Antenna(DRA) is proposed. This antenna exhibits good simulation and measurement results, with a resonance at -15.6 dB at 3.82 GHz, and a radiation efficiency of over 97%. When the input power is below 22.8 mW, the Specific Absorption Rate(SAR) meets the requirements for human health and safety. On this basis, the antenna is optimized into a hybrid dielectric resonator antenna with embedded metal. This optimized antenna has higher gain and stronger directivity in its far-field radiation pattern, which can enhance the signal transmission link of the antenna after it is implanted in the oral cavity. Both proposed antennas are small in size and have excellent performance, and they are expected to be implanted in the human oral cavity based on dental implant technology to monitor the oral environment.

Abstract:

The data volume of millimeter-wave security imaging is relatively small, and the data volume for uncommon types of dangerous objects is even smaller, with the data exhibiting a long-tail distribution. Security inspection requires fast detection speed, and existing deep learning methods are not yet fully applicable to millimeter-wave security imaging datasets.To meet the needs of daily security inspection, a method based on the YOLOv5 algorithm is proposed for feature extraction of human hidden targets in millimeter-wave security radar imaging. Firstly, the YOLOv5 algorithm framework is studied, and a Focal CIoU loss function is proposed to re-weight the samples and reduce the long-tail effect. Next, the dataset is processed by cropping the targets and randomly pasting them into existing images to expand and balance the data volume among different categories, achieving the purpose of resampling. Finally, the Squeeze-and- Excitation Network(SENet) attention mechanism is introduced to improve the accuracy of target recognition. The validation results show that the mean Average Precision (mAP) of human hidden targets using the proposed method reaches 85.4%, which is a 4.7% improvement compared to the original YOLOv5 algorithm. This performance meets the detection requirements for daily usage scenarios.

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:

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:

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 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:

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:

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 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