Abstract:

Terahertz(THz) pulses can be generated by pumping photoconductive antennas, magnetic heterostructures, electro-optic crystals, and air, etc. with femtosecond lasers, which are mainly based on non-thermal effects such as transient changes in carriers and electric polarization under femtosecond excitation. Meanwhile, the laser heating effects inevitably occur during the interactions of femtosecond lasers with matter, and the ultrafast thermoelectric effects and the ultrafast spin caloritronics effects have gained increasing attention in recent years for the ability to generate terahertz waves. In this paper, the research progresses of THz emission induced by two ultrafast thermoelectric effects including the Seebeck effect and the Nernst effect, and two ultrafast spin caloritronics effects including the spin Seebeck effect and the anomalous Nernst effect, are introduced in detail. The ultrafast thermoelectric effects and the ultrafast spin caloritronics effects have exhibited great potential in terahertz generation, which could promote the development and the applications of THz sources and related technologies.

Abstract:

Broadband terahertz radiation sources have an urgent practical application demand in terahertz science and technology, and are the core components for constructing terahertz application systems represented by spectroscopy and imaging. Compared with commonly used commercial terahertz sources, spin-optoelectronics-based terahertz radiation sources have a series of advantages such as ultra-wide frequency spectrum, solid-state stability, and low cost. Currently, the research on the theory, materials, and device technology of spin-optoelectronics-based terahertz radiation sources is still in its infancy. This paper mainly summarizes the terahertz generation mechanism of single-layer ferromagnetic layers in recent years, and the relationship between the polarity of terahertz radiation signals and the excitation configuration. By changing the direction of the magnetic field, the direction of the incident laser, and the direction of sample incidence, the contributions of ultrafast demagnetization, Anomalous Hall Effect(AHE), and Anomalous Nernst Effect(ANE) to the terahertz radiation characteristics can be effectively distinguished, providing a reference for the research in the field of terahertz spin-optoelectronics.

Abstract:

Due to the strong absorption of terahertz(THz) by water, the detection of terahertz spectroscopy for aqueous samples faces significant challenges. To address the issue of high-sensitivity detection of aqueous samples using terahertz spectroscopy, this paper proposes and experimentally verifies a high-resolution frequency-domain spectroscopy system based on terahertz Attenuated Total Reflection(ATR). The system employs an innovative optical heterodyne coherent detection technique, achieving excellent dynamic range and resolution performance. Within the range of 0.3 to 1.2 THz, the peak dynamic range exceeds 100 dB, and the frequency resolution reaches up to 100 MHz. The innovative ATR architecture effectively enhances sensitivity, and in experimental measurements of aqueous solutions with different concentrations of α-lactose, the system has realized direct and accurate quantitative detection of the aqueous samples.

Abstract:

Terahertz communication with high information transmission rate and large bandwidth capacity is considered as a key technology to achieve 6G communication, which requires efficient, stable and compact terahertz sources and detectors. In order to improve the detection performance, the quasi-optical terahertz detector based on integration of Resonant Tunneling Diode(RTD) and on-chip slot antenna is studied. Aiming at the problems of increased loss and parasitic effects of the circuit at high frequencies, a design criterion that jointly considers impedance match factor and antenna radiation efficiency is proposed, and a RTD detector at a small bias voltage is designed at 0.67 THz. The detection performance is characterized by co-simulating of High Frequency Structure Simulator(HFSS) and Advanced Design System(ADS). The current sensitivity of the detector at 0.67 THz is about 2.349 A/W at the input power of -30 dBm. Compared with the design scheme of maximizing impedance match factor at microwave frequencies, the sensitivity is increased by 28.01%.

Abstract:

Gyrotron Traveling Wave Tubes(Gyrotron-TWT) have both high power and broadband characteristics, which have broad application prospects in important military fields such as millimeter wave detection and imaging radar, electronic countermeasures, etc. The gyrotron traveling wave amplifier with large orbit electron beams can operate in high-order harmonic state, greatly reducing the operating magnetic field and even achieving superconducting free operation. It can improve the flexibility and maneuverability of Gyrotron-TWT. This paper optimizes and designs a Ka band second harmonic Gyrotron-TWT with large orbit electron beams, which adopts a longitudinal slot interaction high-frequency structure with dielectric loading to effectively suppress backwave oscillation and improve the stability of device operation. The process of beam wave interaction in the Gyrotron-TWT was simulated by using three-dimensional particle simulation software. The results show that at the condition of the electron beam voltage of 70 kV, the current of 6.5 A, the magnetic field can be reduced to 0.642 T, the corresponding output power can reach 106.5 kW, the bandwidth is 2.1 GHz, and the maximum gain is 35 dB.

Abstract:

The terahertz frequency band, as an important alternative for the next generation of communication technologies, faces the challenge of rapid signal attenuation with increasing carrier frequency. Terahertz wired transmission technology is an effective means to address this issue, and precise control and optimization of material dielectric properties is the key to developing high-performance wired transmission materials in the terahertz frequency range. This paper modifies polymer materials and uses a terahertz time-domain spectroscopy system to test the dielectric properties of composite materials, studying the application of traditional dielectric constant equivalent models in the development of terahertz band materials. Based on the polarization characteristics and response mechanisms of terahertz band materials, a model and method for estimating the dielectric constant and loss tangent of composite materials in the terahertz frequency range is proposed, providing a scientific model guidance for the development of new terahertz wired transmission materials and their performance regulation.

Abstract:

Beam hopping technology improves the resource utilization of the communication system by means of time slicing. However, the existing beam positions are relatively fixed and cannot change with the change of service requirements, and the more beams the beam hopping serves, the greater the queuing delay of the system. When multiple beams work at the same time, the same frequency interference can not be ignored. To solve the above problems, on the basis of beam position optimization, this paper further proposes a resource allocation algorithm that jointly optimizes the slot allocation and the hop beam pattern design. In order to maximize the system throughput, firstly, the phased array antenna can be beam shaped, and the appropriate size of beam position is configured according to the service requirements. Secondly, genetic algorithm is employed to design the hop pattern to avoid co-channel interference. By comparing the system performance parameters before and after the joint optimization, the simulation results show that the method can improve the system throughput and traffic satisfaction, and reduce the system queuing delay.

Abstract:

Under large pitch angles, in the coarse alignment of the Strapdown Inertial Navigation System(SINS) using dual-vector attitude determination, the accuracy of the attitude angles, especially the azimuth angle, varies greatly under different vector combinations, and must be carefully selected. To address this, two of the most commonly used coarse alignment vector combination error equations are presented, and the main error-affecting factors are analyzed. Considering sensor errors, the accuracy of coarse alignment under full attitude angles is simulated using the Monte Carlo method, and a static coarse alignment experiment was conducted on a turntable at a pitch angle of 80°. In the turntable experiment, with SINS gyro error of about 1°/h and accelerometer error of about 0.1mg, the maximum azimuth angle coarse alignment errors for the first and second combination modes were 20° and 7.5°, respectively, with the second combination mode being about one-third of the first. In the simulation test, with SINS gyro error of about 0.1°/h and accelerometer error of about 1mg, at a pitch angle of 80°, the maximum azimuth angle coarse alignment errors for the first and second combination modes were 11° and 2.2°, respectively, with the former being about five times that of the latter. The results of the simulation and experiment show that the vector combination mode under large pitch angles is the most important factor affecting the accuracy of the coarse alignment of the SINS attitude angles and attitude matrix.

Abstract:

Aiming at the baseline optimization of phase interferometer direction finding antenna array, the construction of virtual baseline and the optimization of real baseline are presented. Within the physical constraints of the phase interferometer, by reasonably designing the number of virtual baseline and optimizing the ratio of real baseline, the shortcoming of long real baseline caused by non-optimal real baseline ratio in traditional method is overcome, the optimal method of the length of direction finding antenna array baseline under any condition is realized. Finally, the presented method is employed to give the baseline optimization in 0.35~18 GHz, the ambiguity resolution and the angle measurement accuracy are analyzed and verified. Simulation experiment shows that, under the condition of satisfying angle measurement accuracy, the proposed algorithm can optimize the baseline of direction finding antenna array under any condition by optimizing the real baseline ratio.

Abstract:

According to the application requirements of multi-beam in multi-functional phased array system, a two-dimensional multi-beam forming method based on the combination of optical Blass matrix and a two-stage cascade structure is proposed, in which coherent beam forming method in optical domain is employed to form the first-stage beam in horizontal direction, and the incoherent beam forming method in optical domain is employed to form the second-stage beam in vertical direction, such that the two-dimensional beams can be realized. This architecture bears several advantages:on the one hand, the scale of optical phased array system can be increased from dozens to more than several hundreds units, and this can break the limitation on the scale of the optical array beamforming due to the small quantities of optical wavelengths. On the other hand, it can significantly reduce the number of optical beam forming chips, and the number of beam chips can be reduced from M ² to (N+M) for the system with array number of N×N and beam number of M×M. Moreover, the structure of the multi-beam system can be drastically simplified by combining the photon integration technology, which is helpful to improve the integration degree and engineering realizability.

Abstract:

Aiming at the problem of single frequency band and low integration of traditional RF receivers in multi-band and multi-mode wireless communication applications, a broadband blocker-tolerant RF receiver based on Complementary Metal Oxide Semiconductor(CMOS) with N-path filtering and receiver integration technology is proposed. The receiver integrates an N-path mixer and baseband filter. Layout testing under 65 nm CMOS process shows that the receiver provides more than 60 dB of out-of-band rejection outside of the 5 MHz baseband bandwidth and frequency tuning range of 0.25~2.5 GHz. The front balun's low-noise amplifier achieves a receiver conversion gain of 46 dB while reducing the overall Noise Figure(NF) to 3.1~4 dB. The receiver also achieves 24.5 dBm Out-of-Band Third-order Intercept Point(IIP3) and consumes only 26 mW.

Abstract:

In response to the issue of performance degradation in signal detection bit error rate under spatially correlated channels, a method of multi-antenna diversity reception is proposed. This method reduces the impact of channel spatial correlation on signal detection by increasing the number of receiving antennas, and can flexibly configure the corresponding number of receiving antennas according to actual engineering needs. While avoiding the introduction of high-complexity detection algorithms, it offers superior performance in detection bit error rate. Simulation analysis is conducted on the proposed method using equal gain combining, and the simulation results confirm the effectiveness of the method.

Abstract:

With the continuous advancement of the construction and development of urban rail transit networks, people's demand for transportation capacity is increasing day by day. Therefore, the shortage of on-board computing power has become one of the important issues, making it necessary to explore new solutions. In recent years, Edge Intelligence(EI) has emerged as a new field. Through edge intelligence, complex computing tasks can be offloaded to trackside computing servers, fundamentally liberating the computing power of onboard equipment. In this case, we can focus the onboard devices on performing simple, low energy computing tasks, while leaving most of the computing work to edge servers. Based on the above idea, this paper proposes a new train autonomous control system, which uses Google Kubernetes high reliability edge computing platform to realize the train autonomous control algorithm. In addition, we use the Linear Quadratic Gaussian(LQG) algorithm to model the train autonomous control process and utilize cloud security computing to ensure the high reliability of the entire system. At the same time, due to its ability to effectively avoid the impact of local faults, the system also exhibits excellent performance in terms of communication packet interval delay performance. After extensive experimental verification, we can conclude that the proposed train autonomous control system has high operational reliability and data security, as well as low communication packet delay performance. This result further proves that using the autonomous train operation control system can significantly improve the efficiency and safety of train operation, thereby improving the quality of train operation.

Abstract:

To enhance the automatic detection and tracking capabilities of passive weak targets under low signal-to noise ratios and in the presence of multiple target interference, a novel algorithm with multi-line spectrum fusion and optimal line spectrum target automatic tracking is proposed. This algorithm is based on line spectrum detection and automatically tracks targets with fused multi-line spectrum features, establishing the criteria for the creation, deletion, fusion, and association of line spectrum targets. It employs a Multi-Hypothesis Tracking(MHT) algorithm tailored for trajectories to automatically track multiple targets, offering the advantages of low computational complexity and strong weak target tracking capability. Analysis of sea trial data indicates that even in the presence of strong target interference, this algorithm can still provide stable tracking for weak targets with line spectrum characteristics.

Abstract:

Micro-Electro-Mechanical Systems(MEMS) inertial switches are passive electronic devices that integrate sensing and actuation. They have the advantages of small size, light weight, easy integration, good processing consistency, and no need for assembly. They have a broad application prospect in fields such as the automotive industry, aerospace, and military equipment. The application scenarios of low-g value MEMS inertial switches are mainly for triggering specific functions during the acceleration/deceleration process of aircraft. In the design, it is necessary to ensure low spring stiffness and a large mass block volume, which poses certain difficulties in structural design and processing technology. This paper introduces the basic physical model and working principle of low-g value MEMS inertial switches, discusses the current research status at home and abroad, summarizes the key issues that urgently need to be addressed at this stage, and proposes corresponding solutions, providing beneficial references for subsequent research.

Abstract:

Theoretical and experimental research of the spatial resolution characteristics of magnetic focusing framing tubes with single magnetic lens, double magnetic lenses and triple magnetic lenses are simulated and studied by Monte Carlo method, finite difference method and finite element method. The relationship among the number of short magnetic lenses and the surface curvature of Micro-Channel Plate(MCP), imaging range and rotation angle is studied. The results show that the more the number of short magnetic lenses, the smaller the curvature of the imaging surface, the flatter the image surface. The imaging range increases with the increase of the number of short magnetic lenses; the electron rotation angle at the MCP point decreases with the increase of the number of short magnetic lenses. With triple magnetic lenses, the spatial resolution of the framing tube is 10 lp/mm within the diameter of 36 mm.

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:

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:

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:

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:

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:

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 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 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 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:

Wavelet denoising is an important application of wavelet analysis in engineering.The keys of wavelet denoising,namely how to select threshold and how to utilize the threshold to dispose wavelet coefficients,are introduced.Via the noised simulated signal e

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