Abstract:

To promote the application of fifth-generation mobile communication technology(5G) in the construction of high-speed rail dedicated networks, this paper takes the Xiamenbei Railway Station in the 2.1 GHz frequency band as the research scenario, studying the significant multipath spatial characteristics brought about by objects such as columns, tracks, and platforms in the scenario. Through Ray Tracing(RT) simulation, multidimensional multipath data from the transmitter to the receiver in the high-speed railway station scenario is obtained; based on the K-means clustering algorithm, the multipath signals are clustered, and relevant cluster parameters are extracted and analyzed to complete the construction of the Cluster Delay Line(CDL) model for the high-speed railway station scenario. This provides spatial domain information of multipath for different polarization combinations of transmitters and receivers in the high-speed railway station scenario, complementing the channel model of high-speed railway station scenario for 5G-Railway(5G-R), and serving the construction of dedicated mobile communication systems for railways using 5G.

Abstract:

Urban rail transit is one of the primary systems for urban transportation capacity. With the increasing demand for the development of smart cities in recent years, the design, research, and optimization of smart rail transit systems have become the research direction and focus for many scholars. Smart rail transit systems require trains to have intelligent computing power to meet a variety of intelligent service needs. Due to the numerous limitations of on-board equipment in trains, it is not practical to deploy high-performance computing devices on them, hence the need to introduce other devices to provide computational support. This study, aimed at the special scenarios of smart rail transit systems, designs a cloud-edge collaborative computing architecture for intelligent tasks based on 5G and edge intelligence. The resource allocation process in this architecture is mathematically modeled and transformed into an optimization problem that minimizes task latency. To solve this optimization problem, this paper employs a discrete stochastic approximation algorithm to minimize the total processing delay of tasks in the smart rail transit system. Simulation results indicate that the algorithm can effectively reduce the processing delay of intelligent tasks in smart rail transit systems.

Abstract:

Urban rail transit plays a significant role in alleviating urban traffic congestion, and the coordinated control of multiple urban rail vehicles has been a research hotspot in recent years. The multi-vehicle coordinated computing task is limited by communication, leading to issues such as poor resource allocation balance, slow system response to environmental changes, and limited cooperative operation capabilities. The integration of 5G communication and Mobile Edge Computing(MEC) can effectively improve the real-time and accuracy of task processing, enhancing the overall system performance. This paper designs an autonomous coordinated computing architecture for urban rail vehicle operation control systems based on 5G and MEC. According to the characteristics of multi-vehicle coordinated control tasks, the problem of edge server selection in multi-vehicle coordinated computing offloading is modeled as a Multi-Armed Bandit(MAB) learning model, and a solution based on the Upper Confidence Bound(UCB) algorithm is proposed to minimize the overall energy consumption and latency of the urban rail vehicle multi-vehicle coordinated control system. Simulation results show that the proposed algorithm model has significant performance advantages in terms of average reward, best selection probability, average execution latency, and weighted total cost.

Abstract:

To assist in determining the base station spacing for the new generation of mobile communication systems for 5G-Railway(5G-R) in complex railway environments, a link-level transmission rate simulation technology is proposed. This technology relies on various empirical propagation models to obtain the path loss of electromagnetic waves in different scenarios along the railway line, thereby assessing the Reference Signal Received Power(RSRP) of the wireless link. Based on the obtained RSRP data, link-level transmission rates are calculated by using the Monte Carlo simulation method. Simulation results indicate that in open-field scenarios, base station spacing can be set between 2 000 meters to 3 000 meters, while in urban and complex terrain environments, the spacing should be reduced to maintain performance. This technique accurately reflects the signal transmission characteristics of 5G-R systems across various scenarios, including the changes in transmission rate and RSRP with different base station spacings. And it provides a scientific basis for future base station deployment planning in 5G-R systems.

Abstract:

In response to the difficulty in detecting defects in high-speed rail clip springs caused by complex lighting environments, an improved Faster Region Convolutional Neural Networks(R-CNN)-based defect detection method for clip springs is proposed. By extracting defect feature maps through multi-layer convolutional neural networks, the network's attention to defect features is enhanced, and the impact of interference from complex lighting environments is reduced. A region proposal network is designed to generate candidate regions, and based on these regions, pooling is performed to extract the corresponding specific defect locations in the feature maps. The fully connected layers of the region proposal network are employed to calculate the specific categories and precise locations of defects, yielding the final detection results. The proposed algorithm can fully suppress the interference of lighting environments, significantly enhance the representation ability of defect features, simplify the image pre-processing stage, and reduce the requirements for the quality of the original image. Experimental results show that the proposed algorithm can effectively detect defects in high-speed rail clip springs, and compared to existing algorithms, it has a higher accuracy, stronger robustness, and significantly improved computational efficiency.

Abstract:

A Noise Source(NS) is a device that generates controllable noise(with controllable frequency and power)，and it is an important tool in the development process of devices. Terahertz noise sources have important applications in terahertz device noise figure testing, calibration of space-borne microwave radiometers, imaging, and spectral analysis. This article systematically reviews the development and research status of Terahertz(THz) noise sources at home and abroad, analyzes the technical characteristics of terahertz noise sources based on thermodynamics, electronics, and photonics, and looks forward to their future development directions.

Abstract:

The existing passive metasurfaces have relatively limited functions. To increase the flexibility of controlling terahertz waves, a polarization-multiplexed reflective metasurface is proposed. This metasurface is capable of various functions such as beam deflection, dual-focus focusing, focused vortex, and far-field imaging. At a frequency of 1 THz, by separately incident x-polarized and y-polarized waves, the metasurface successfully generated two deflected beams and achieved dual-focus focusing on the focal plane. In addition, the metasurface also realized focused vortex beams with a topological charge of l=+2 and far-field imaging under the conditions of x-polarized and y-polarized wave incidence, respectively. The designed metasurface demonstrates the ability to flexibly manipulate terahertz waves under different polarization wave incidences, showing potential application prospects in the field of terahertz communication.

Abstract:

The sensor optimization deployment is a multi-objective optimization problem involving sensor coverage effectiveness, frequency conflict probability, and resource utilization. The existing sensor optimization deployment methods mostly adopt weighted approaches to transform multiple optimization objectives into a single objective problem for resolution, which not only relies on prior knowledge but also leads to the loss of diversity in optimal solutions. To address these issues, a Collaborative evolution Multi-Objective Particle Swarm Optimization(CoMOPSO) algorithm is proposed. It designs a collaborative evolution framework that guarantees the convergence of high-dimensional problems through the convergence of the population, and rapidly approaches the Pareto optimal frontier. The diverse population uses the ??-dominance method to ensure the integrity and diversity of the global and local optimal solution sets. A fast non-dominated sorting and elite individual preservation strategy is employed to enhance the quality of solutions. Experimental results demonstrate that, for the sensor optimization deployment problem, the proposed method outperforms traditional optimization algorithms in terms of Inverted Generational Distance(IGD) and M3* indicators, exhibiting better convergence and diversity and effectively improving the performance of sensor networks.

Abstract:

Dual-satellite Time-Difference of Arrival(TDoA) and Frequency-Difference of Arrival (FDoA) positionings utilize just two satellites to locate the emitter, bearing lower cost and difficulty than multi-satellite positioning, and better real-time performance than single-satellite positioning system, more suitable for practical applications. In order to solve the nonlinear optimization problem in the process of solving the TDoA/FDoA equation, an Improved Particle Swarm Optimization(IPSO) algorithm is put forward. Dual-satellite TDoA/FDoA location systems use Newton method with high precision, but there exists unsolvable blind areas of initial value of iteration. To address this issue, an cascaded localization method of IPSO and Newton iteration is proposed, in which the IPSO algorithm gives coarse localization result with rapid speed and reliable convergence, and this coarse result is used as the initial value of Newton iteration, so as to reduce the positioning error and avoid non-convergence. By analyzing the simulation results, the proposed algorithm not only increases the success rate of effective initial point selection by 48.15% compared to the Newton method, but also cuts the computation and improves the computational speed.

Abstract:

The conventional classification and identification of cruise missiles, air-to-ground missiles, and guided bombs rely heavily on the kinematic characteristics of the targets, often using parameters such as the target's altitude and speed as the basis for classification judgment. With the advancement of missile weapon development technology, single-dimensional kinematic characteristics can no longer meet the demand for refined identification. To address this issue, a classification and identification method for missile targets has been designed, which integrates the kinematic characteristics and Radar Cross-Section(RCS) series characteristics of the targets. By employing a multi-feature hierarchical identification approach, it achieves the classification and identification of the three types of missile targets. Simulation test results indicate that the classification accuracy of this method for the three types of missile targets is better than 95%, validating the effectiveness of the method.

Abstract:

Absorption boundary condition is an important condition for solving electromagnetic computing problem by Finite Difference Time Domain(FDTD) algorithm. First of all, four absorption boundary methods are selected, and the principles of Convolution Perfectly Matched Layer(CPML), Surface Impedance Boundary Conditions(SIBC) and the absorbers are derived respectively; FDTD algorithm is programmed and calculated by Matlab software. Then, the four methods are applied to two microstrip structures, the low-pass filter and the branch coupler, and the reflection coefficient is calculated. By changing the thickness of the air layer and the iteration step size, the four methods can get the correct results. Finally, the results of the two models are compared and analyzed in terms of computing time, memory usage and percentage of error. Compared to other absorption methods, SIBC has the least memory usage, higher computational efficiency, and an error percentage of 1.63%.

Abstract:

The function and working principle of the True-Time Delay(TTD) chip has been studied and the chip has been applied in phased array radar. Based on GaAs Pseudomorphic High Electron Mobility Transistor(PHEMT) technology, three broadband millimeter-wave TTD chips are designed and fabricated. The measured results on wafer show that the 6 bit TTD provides 0.446 ps up to 28.125 ps in the frequency range 32 GHz-40 GHz, the TTD phase error for all 64 bit states is -2°~9°, the Insertion Loss(IL) is less than 19 dB, and the 64 states insertion variation is reduced to ±1 dB, the input and output Voltage Standing Wave Ratios(VSWRs) are better than 1.5 on the whole bandwidth; the 4 bit TTD provides 7.142 ps up to 107.148 ps in the frequency range 32~40 GHz, the TTD phase error for all 16 bit states is better than±12°, the IL is less than 12 dB, and the 16 states insertion variation is reduced to ±1 dB, the input and output VSWRs are better than 2.0 on the whole bandwidth; the 3 bit TTD provides 28.57 ps up to 200 ps in the frequency range 32~40 GHz, the TTD phase error for all 8 bit states is -10 °~22 °,the IL is less than 14 dB, and the 8 states insertion variation is reduced to ±1 dB, the input and output VSWRs are better than 1.8 on the whole bandwidth. The TTD chips are characterized with ultra wideband, large time delay and compact size, and mainly applied to wideband active phased array applications.

Abstract:

For the problem of symbol rate estimation in non-cooperative communication, an algorithm based on empirical mode decomposition for symbol rate estimation is proposed. The algorithm performs a low-order Empirical Mode Decomposition(EMD) on the instantaneous amplitude of the signal to find the intrinsic mode components that contain information about the symbol rate; then, it estimates the symbol rate through spectral line detection. This algorithm can effectively reduce the impact of interference on estimation performance by separating frequencies, thereby improving estimation accuracy. Simulation results show that the algorithm can obtain an estimate of the symbol rate directly from the frequency band signal under low signal-to-noise ratio conditions.

Abstract:

In recent years, deep learning methods have been widely applied in the field of signal processing and have achieved good results. Deep learning methods can automatically acquire useful signal features from massive signal data using neural network models designed by experts, but the manual design of deep neural network models remains a time-consuming and error-prone process. To address this, a method for Automatic Modulation Classification(AMC) based on progressive neural architecture search is proposed. This method can automatically design network structures according to specific modulation classification tasks and obtain the optimal lightweight deep neural network by following a search strategy that maximizes the model performance. Simulation results show that compared to deep learning-based modulation classification methods, the proposed method can achieve optimal modulation classification accuracy without manual design of neural networks, with low parameter volume and floating-point operations, achieving an average recognition accuracy up to 92.82%.

Abstract:

Due to the exposure of data caused by open source code, traditional methods cannot block the transmission of attacked data packets, resulting in the inability of data to autonomously defend. Therefore, a network link data tampering autonomous defense system based on Snort is designed. In the hardware part of the system, a packet sniffer is adopted to capture Snort messages, and the layered decoding is integrated into text information through an information decoding module. The integrated text information is sent to the system database through the network for processing high-volume alert data and storing records. In the system software section, a network depth defense model based on Snort is constructed to achieve real-time detection and automatic interception of tampering attacks. Based on the transmission characteristics of information packets in the network, the transmission distance between different nodes is calculated and the location of defense nodes is determined. The data transmission path is derived when the link layer data is subjected to tampering attacks, and an autonomous defense function is constructed for data tampering, therefore the autonomous defense of data is achieved. Using wavelet denoising data processing technology to obtain time-series data, using inverse wavelet transform reconstruction to obtain denoised data, the design of an autonomous defense system for data tampering is completed. According to the experimental results, the system has a high density of secure transmission of network link data, and the maximum success rate of key recovery can reach 98%, demonstrating strong robustness.

Abstract:

In response to the issues of low tracking accuracy in video sequences due to factors such as appearance changes, background clutter, and severe occlusions, a novel two-stage adaptive tracking model is proposed. This model includes two phases: target detection and bounding box estimation. In the target detection phase,the model roughly locates the target; in the bounding box estimation phase, the exact position of the target is determined. To address the complexity of video scenes and the challenges of tracking small targets, multi-feature fusion technology is employed to construct a rich target representation. Experimental results show that compared with models such as Simple Online and Realtime Tracking(SORT), Tracktor++, FairMOT, and Transformer, this model demonstrates the best overall performance, effectively balancing the relationship between computational speed and tracking accuracy, and showing good potential for application.

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:

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