Special Column-5G Communication

Hybrid of check matrix construction algorithm based on iteration coding algorithm


Author:Meng Jiahui,Zhao Danfeng,Zhang Liang

Author Affilications:School of Information and Communication Engineering,University of Engineering of Harbin,Harbin 150001,China

Abstract:In order to ensure the reliability, stability and high transmission rate of fifth-generation mobile communication technology(5G), this paper proposes a hybrid check matrix construction algorithm based on iterative coding algorithm with linear coding complexity. Firstly, this paper improves the traditional iterative coding algorithm and makes it suitable for non-binary low density parity check(NB-LDPC) codes. Then it adopts backward iterative method to change the coding scheme and the structure of the check matrix so that the progressive edge growth(PEG) algorithm has a lower triangular structure and uses it as the base matrix. Finally, a QC-LDPC algorithm with a lower triangular structure is used to generate a cyclic shift matrix and a finite field coefficient matrix. At the same time, the effect of the short loop is eliminated, and an optimal check matrix is selected from the algorithm. Simulation results show that the non-binary LDPC code constructed by the hybrid construction algorithm not only has linear coding and storage complexity, but also has strong error correction capability.
Key word:
NB-LDPC code
iterative encoding algorithm
hybrid construction algorithm

Research on the combination of NOMA and SWIFT based on Internet of Things


Author:Qiu Huan,Qiao Kun

Author Affilications:School of Electronic Engineering,Xi′an Shiyou University,Xi′an 710065,China

Abstract:This paper presents a non-orthogonal multiple access(NOMA) relay method which is based on mmWave wireless heterogeneous system and can support Internet of things(IoT) applications. The scheme takes advantage of the deployment specialty of low power relays,together with energy harvesting capabilities of IoT devices,so that it can infer the performance of UEs with relay collaboration. With the help of a relay or IoT device, the downstream NOMA transmission consists of two phases.(1)The base station(BS) transmits the composite signal to the user equipment(UE) and the selected relay device simultaneously by applying the NOMA. (2)The BS sends another signal to the UE 1 while the relay device transmits the signal to the UE 2. The simulation results show that the method designed in this paper is feasible and effective.
Key word:
heterogeneous network

Analysis of fuzzy direction control in intelligent vehicle system


Author:Huang Junjia,Yu Zhixian,Chen Rui,Tang Xiaoyu

Author Affilications:School of Physics and Telecom Engineering,South China Normal University,Guangzhou 510006,China

Abstract:Under the background of 5G technology, this paper studies the direction control field of intelligent vehicle automatic driving. Most of the existing intelligent vehicle recognition algorithms rely on the error of center line to control the intelligent vehicle, and it is difficult to deal with the track elements′ center line which is not available. In view of this situation, this paper analyzes the robustness of the intelligent vehicle servo system, and explains the influence of the intelligent vehicle algorithm and mechanical characteristics on the robustness of the servo system. On this basis, a specific fuzzy direction control strategy is proposed, and the superiority of the strategy is verified by experiments. The analysis, solution strategy and experiment of intelligent vehicle system are beneficial to improve the intelligent vehicle system.
Key word:
intelligent vehicle system
direction control strategy
mechanical characteristics

Design and implementation of beam failure recovery in 5G


Author:Gao Cheng,Zhu Xuetian,Liu Chunhua

Author Affilications:Network Technology and Planning Department,China Telecom Beijing Research Institute,Beijing 102209,China

Abstract:In a 5G millimeter wave system, beam misalignment between a gNB and an UE may occur due to sudden fluctuations in the channel, user rotation, and so on. The beam failure recovery mechanism can help the gNB or the UE change its current failed beam to alternative(feasible) beam(s) based on beam measurement, thereby avoiding the frequent radio link failure caused by beam misalignment. This paper systematically expounds the design and implementation of beam failure recovery in 5G, including beam failure detection, candidate beam identification, beam recovery request transmission and gNB response,to provide essential reference for further research on beam failure recovery.
Key word:
beam failure recovery
beam failure detection
new candidate beam identification
beam failure recovery request transmission
gNB response

Interference analysis of 5G system in 4 400~4 500 MHz frequency band to radio altimeter


Author:Jia Di1,Li Jingchun2,Yang Wenhan2,Bao Yao2

Author Affilications:1.School of Information Engineering,Hebei University of Technology,Tianjin 300401,China; 2.The State Radio Monitoring Center,Beijing 100037,China

Abstract:Based on the parameters and characteristics of the fifth generation mobile communication(5G)system and the radio altimeter, this paper uses the antenna model and propagation model provided by the International Telecommunication Union(ITU) related proposals. Through Monte Carlo simulation, the coexistence of the 4 400~4 500 MHz band 5G system and the 4 200~4 400 MHz band radio navigation service(radio altimeter) is carried out. The results show that the 5G system does not cause harmful interference to the radio navigation service(radio altimeter) in the relevant frequency band.
Key word:
aeronautical radio navigation service
radio altimeter
coexistence research

5G key technologies and business forecast


Author:Zhu Xuetian,Xia Xu,Qi Fei

Author Affilications:Department of Network Technology and Planning,China Telecom Beijing Research Institute,Beijing 102209,China

Abstract:On June 14,2018,the 3GPP plenary meeting(TSG#80) approved the freeze of the independent networking function of the fifth generation mobile communication technology standard(5G NR). Coupled with the NR standard which was completed in December 2017, 5G has completed the first phase of full function standardization, and has entered a new stage of industrial sprint. The SA function freeze not only enables the 5G NR to have the ability to deploy independently, but also brings a new end to end new architecture, enabling the intelligent development of enterprise customers and vertical industries, bringing new business models for operators and industrial partners, and opening a new era of full connection. This paper firstly introduces 5G network key technologies, such as large-scale antenna, service-oriented architecture, edge calculation and network slicing, and analyzes the process and development status of 5G commercial application on the basis of elaborating the future business model applied in the three scenarios.
Key word:
network slicing

Review and Comment

Review of knowledge graph refinement


Author:Xie Gang1,2

Author Affilications:1.Institute of Automation,Chinese Academy of Science,Beijing 100080,China; 2.School of Big Data and Computer Science,Guizhou Normal University,Guiyang 550001,China

Abstract:Knowledge graph is a new knowledge representation method in the mobile Internet era. Knowledge graph refinement is one of the main contents in application of knowledge graph and its main goal are completion and error detection. At the same time, knowledge graph refinement is usually applied in areas of the information retrieval, robot, intelligent answer and so on. At result, studies on knowledge graph refinement had great significance. This paper addresses the methods of knowledge graph refinement and finally presents challenges of know-ledge graph.
Key word:
knowledge graph
error detection

A review of cyber-physical systems


Author:Li Fujuan1,Wang Qun1,Qian Huanyan2

Author Affilications:1.Department of Computer Information and Cyber Security,Jiangsu Police Institute,Nanjing 210031,China; 2.Computer Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China

Abstract:Cyber-physical Systems(CPS)is an intelligent complex system which is combined with the discrete mode of information space and continuous dynamic mode of the physical world, it consists of perception,computation,communication, control,etc. Firstly,the basic concept and structure of CPS are analyzed. Then,the technical system of CPS is presented. At the same time,the key technologies are discussed which involves three aspects:intelligent perception and automatic control,network communication technology and intelligent platform service technology. Finally, according to industrial application,the main challenges to be deal with for CPS are pointed out, and the future research directions are discussed.
Key word:
cyber-physical systems(CPS)
intelligent perception
depth computation
precise control
real-time communication

Microelectronic Technology

Trusted root and trusted computing platform architecture design based on physical unclonable function


Author:Wu Jin,Xu Jinfu

Author Affilications:The PLA Information Engineering University,Zhengzhou 450001,China

Abstract:Physical Unclonable Functions(PUFs) are highly flexible in applications such as device authentication and secure key storage, and are widely used in embedded system security. In this paper, we use PUF technology to provide the root of trust(RoT) for dual-core security architecture, and design the chain of trust and key update protocol based on PUF-based RoT, to ensure the gradual extension of trusted relationship and the reliability and security of secure boot on SoC system. The experimental results show that PUF-based RoT can operate in a dual-core isolated SoC system with a small TCB, and its random number seed and unique device key are resistant to multiple attacks. It proves that the PUF can provide the security and flexibility RoT for the embedded system.
Key word:
the root of trust
the chain of trust
trusted computing

The application of 3D design technologies in SiP


Author:Li Yang

Author Affilications:AcconSys Technology Co.,Ltd.,Beijing 100045,China

Abstract:SiP(System-in-Package) is the latest microelectronic packaging and system integration technology, now it has become a hot spot in the development of electronic technology. The most distinctive feature of SiP is the use of 3D(Three Dimensions) technology in package. Through 3D technology, we can achieve higher system integration and package more chips in a smaller area. From the design point of view, this paper sets forth the 3D design technology applied in SiP, including 3D substrate design technology and 3D assembly design technology, and expounds the specific ideas and methods of 3D design, which can be used for reference by engineers in designing 3D SiP.
Key word:
3D SiP
3D design technology
3D substrate design
3D assembly design

Dual-band ambient energy harvesting circuit design


Author:Xu Lixiang1,You Bin1,Hua Fuchun2

Author Affilications:1.Electronic Information College,Hangzhou Dianzi University,Hangzhou 310018,China; 2.Lanzhou Xigu District Education Bureau,Lanzhou 730000,China

Abstract:A low power dual band energy harvesting rectifier is designed ,which is matched by T matching network.Futhermore,two stubs are used to expand the matching bandwidth. The testing result shows that the rectifier matchs well at 1.84 GHz and 2.45 GHz. When the single input power is 0 dBm and load is 5.1 kΩ,the RC-DC efficiencies are 5.12% and 9.97% at 1.84 GHz and 2.45 GHz,respectively.The output voltage can reach 0.51 V and 0.71 V,respectively.When both frequency signals are input,the efficiency is 14.9%,the output voltage can reach 0.87 V. This energy can be stored to power some low-power devices.
Key word:
impedance matching

Function verification and implementation of block random access memory based on FPGA


Author:Luo Jun,Fan Jianfeng,Lv Hongfeng,Wang Xiaoqiang,Luo Hongwei

Author Affilications:China Electronic Product Reliability and Environmental Testing Research Institute,Guangzhou 510610,China

Abstract:Field programmable gate array(FPGA) has a wide application in signal processing, hardware accelerating and chip prototype verification because of its rich on-chip resources, flexibility and programmability. As a major resource in FPGA, block random access memory(BRAM) has the characteristic of high speed and high-capacity. To solve the critical timing convergence in high speed BRAM, function verification method for high speed BRAM based on cross timing domain has been proposed. The presented method has been verified by functional simulation and using FPGA. Experiment result has shown that the proposed approach can meet the functional verification of high speed BRAM up to 640 MHz,and it has the feature of modularization which can be easily constructed to test BRAM of high-capacity.
Key word:
field programmable gate array
block random access memory
high speed
function verification

Time-domain temperature sensor based on converter with temperature compensation


Author:Li Mengyu,Huang Letian,Li Qiang

Author Affilications:Institute of Integrated Systems,School of Electronic Science and Engineering, University of Electronic Science and Technology of China,Chengdu 610054,China

Abstract:This paper made a corresponding improvement on influence of temperature on the performance of the time-domain temperature sensor circuits. According to the qualitative relationship between temperature coefficient and size of transistors, the aspect ratio of the transistors in sensing part is improved to increase its temperature coefficient. Besides, a current mirror for temperature compensation is added to the ring oscillator of TDC(Time-to-Digital Converter) and the parameters of inverters are adjusted so that the temperature drift of TDC is near zero at the chosen temperature range. The method reduces the total power consumption and power density of the circuit, thereby reducing the performance loss caused by self-heating and self-heating of the circuit.
Key word:
temperature sensor
temperature drift
current mirror

Design of high-speed and low-latency Viterbi decoder


Author:Yang Min

Author Affilications:School of Electronic Information and Communications,Huazhong University of Science and Technology,Wuhan 430074,China

Abstract:In a Viterbi decoder, there are two known memory organization techniques for the storage of survivor sequences, namely register exchange method and traceback method. This paper presents a new survivor path storage scheme that enables short latency in area-efficient Viterbi decoder. This is achieved by introducing part register exchange method into traditional traceback method. Since more path information is read per clock,the traceback time is largely shortened, and the path memory size is also saved greatly. On contrast to conventional register exchange and traceback method, the new method has obvious advantage of hign speed,low resource cost and low-latency.
Key word:
convolutional code

Embedded Technology

Real-time acceleration design of Canny algorithm based on Vivado HLS


Author:Tan Jiancheng1,2,Wu Dingxiang2,3,Li Mingxin1,2,Tang Lijun1,2

Author Affilications:1.School of Physics and Electronic Sciences,Changsha University of Science & Technology,Changsha 410114,China; 2.Hunan Province Higher Education Key Laboratory of Modeling and Monitoring on the Near-Earth Electromagnetic Environments, Changsha 410114,China; 3.Changsha Billion Set Intelligent Technology Co.,Ltd.,Changsha 410004,China

Abstract:On the shortcomings of Canny edge detection algorithm in the real-time image processing time-consuming and large amount of data for computation, the hardware acceleration method of Canny edge detection algorithm using Vivado HLS is proposed. The method, implemented hardware acceleration, generates the RTL level hardware circuit corresponding to the algorithm of the FPGA logic resources. The results show that the method can quickly detect the edge of the image and effectively reduce the difficulty of FPGA design image algorithm, which can be applied to the real-time video image processing.
Key word:
image processing
Vivado HLS
edge detection
hardware acceleration

An improved method of frequency domain processing for image deblurring system


Author:Yuan Jin,Liu Yunfei

Author Affilications:Institute of Information Science and Technology,Nanjing Forestry University,Nanjing 210037,China

Abstract:In engineering application, when dealing with fuzzy images,due to the way of space deconvolution is more difficult, the frequency domain transformation of the image is usually processed and implemented in the frequency domain.In the light of the frequency domain processing of image deblurring system has such problems as large consumption of hardware resources, poor flexibility of conversion and long processing time, etc. Based on the DE2 development board as the hardware platform, combined with the characteristics of fuzzy image and deblurring algorithm, this paper designs and implements a frequency domain processing method for image deblurring system by means of input data preprocessing, in situ calculation, throwing position, pipeline structure and parallel processing. The experimental data show that the accuracy of the method in the frequency domain processing of the image data is kept above 98%, and the hardware resources only use 9 162 logical units. The experimental results show that the system designed in this paper is superior to other similar systems in processing precision and resource utilization.
Key word:
format conversion
frequency domain conversion

Design and implementation of the BSP for automated monitoring system based on Zynq-7000


Author:Song Kai1,2,Gao Han1,2

Author Affilications:1.Faculty of Information Technology,Beijing University of Technology,Beijing 100124,China; 2.Beijing Engineering Research Center for IoT Software & Systems,Beijing 100124,China

Abstract:In this paper, the design method and application process of a Board Support Package(BSP) based on the Zynq-7000 All Programmable SoC(AP SoC) is implemented. The BSP design is mainly for the field of industrial automated monitoring. It provides an effective implementation process of embedded system BSP, which is beneficial to improve the development efficiency of industrial automated monitoring system. In this paper, In view of the industrial monitoring equipment that uses serial communication mode, the FPGA engineering for small automatic monitoring system is designed, and the embedded Linux system is built by PetaLinux tools, which are designed specifically for FPGA-based SoC. Finally, the correctness and stability of the BSP design are verified with the self-developed hardware platform based on Zynq XC7Z010 series model chip.
Key word:
automated monitoring system

Design of decoding system to rotary transformer based on AD2S1205


Author:Li Yulong,Pi Dawei,Yan Mingshuai

Author Affilications:School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210000,China

Abstract:In order to obtain the rotor position information and speed information of permanent magnet synchronous motor with magnetic resistance rotary transformer,the system of spin decoding is designed.The design is based on decoding chip AD2S1205.Firstly, the working principle of the magnetic resistance rotary transformer is analyzed.Then the hardware circuit of the rotary decoding system is designed, and the rotor position information and motor speed information are calculated by C code.Finally, single chip microcomputer and motor drive plate are used to drive motor rotation.The rotor position information and motor speed information are sent to dSPACE in real time through the CAN bus.The experimental results show that the system can effectively solve the motor rotor position information and the motor speed information.
Key word:
variable-reluctance resolver
decoder chip
CAN industrial network
hardware circuit
C code

Acupoint positioning system based on PSO-BP neural network


Author:Yang Xiangping,Wu Yudan

Author Affilications:College of Mechanical Engineering,Donghua University,Shanghai 201600,China

Abstract:The location of acupoints will directly affect the therapeutic effect, so we designed a prediction model of relative coordinates based on particle swarm optimization and neural network(PSO-BP), and then combined with ARM to form a system for locating human acupuncture points. Firstly, PC machine is used for MATLAB simulation training and learning. After that, the optimal weights and thresholds are saved, and the algorithm is embedded in ARM, and online prediction is transformed into offline process. The experimental results show that the BP neural network optimized by particle swarm optimization can effectively improve the local extreme defects. It can be applied to locate the location of the acupoints at the location end, and display the information of the points in LCD. After the control terminal receives the location data, it can perform the movement operation on the motor.
Key word:
acupoint coordinates
particle swarm optimization
BP neural network

Measurement Control Technology and Instruments

A self-monitoring and management technology for systems based on real-time current monitoring and analysis


Author:Yang Xiaojun,Qian Cheng

Author Affilications:The 28th Research Institute of China Electronics Technology Group Corporation,Nanjing 210007,China

Abstract:The high reliability and easy testing of the information system are important factors to ensure the efficiency of the information system. Some old systems are constrained by the technological development of the past time, and can not be easily tested. How to improve the testability of these systems so as to ensure the high availability of the system is one of the key technologies for the technical transformation of information systems. In this paper, the power system architecture of a class of systems is transformed to increase the real-time state monitoring, self monitoring and diagnosis function of the system current. By monitoring the current of the equipment in the system, the on-line self state monitoring and diagnosis of the running state of the system is realized. It provides the auxiliary decision support function for the maintenance of the system, which is of great significance to improve the precision maintenance and high availability of the system.
Key word:
information system
self-monitoring and management
high availability

Design of portable signal acquisition system based on FPGA and NAND Flash


Author:Zhou Hao,Wang Haoquan,Ren Shilei

Author Affilications:College of Information and Communication Engineering,North University of China,Taiyuan 030051,China

Abstract:Aiming at the problem of low sampling rate and poor portability in the current signal acquisition system, this paper designs a signal acquisition system with high speed and strong portability based on FPGA. Firstly, FPGA samples the signal at a high speed through controlling the ADC. And then,the data is stored in the NAND Flash by using the DMA(Direct Memory Access) mode. Finally, the signal stored in the NAND Flash chip could be demonstrated live by using the LCD. Paper begins with describing the overall design framework of the system. Then, it introduces the hardware design and the implementation, followed by the outcome produced by the experiment that the signal acquisition system samples the ultrasonic signal. The experiment results show that the system could carry on a long-time and multi batch data acquisition stably at relatively high sampling rate.
Key word:
signal acquisition system
NAND Flash
LCD display

An implementation of high speed Sobel based on CORDIC


Author:Huang Hu,Yang Ding,Lei Yuhui,Xie Jiaxun,Cheng Shiyao,Zou Yu

Author Affilications:College of Information Science and Technology,Chengdu University of Technology,Chengdu 610059,China

Abstract:The acceleration method proposed in this paper aims to improve the processing speed of image edge detection. On the basis of parallelism and pipeline technique, it works in the FPGA platform and uses extended data bits and the pipelined CORDIC algorithm covering all angles so that the efficiency of Sobel algorithm can be improved. The experimental results show that compared with the traditional acceleration method, under the premise of ensuring the operation precision, this method can speed up the efficiency by 63.53 percent.
Key word:
edge detection
CORDIC algorithm
hardware accelerator
programmable device

A non-intrusive load monitoring and identification system based on cloud platform


Author:Chen Pengxin1,Zhong Sidong1,2

Author Affilications:1.School of Electronic Information,Wuhan University,Wuhan 430079,China; 2.National Key Laboratory of Surveying and Mapping of Remote Sensing Information Engineering,Wuhan University, Wuhan 430079,China

Abstract:In order to monitor the load′s running condition and identify the load′s type in real time and long distance, a non-intrusive load monitoring system and a load identification algorithm based on PCA and kNN are designed and developed. On the side of power supply inlet, operating current is sampled through putting a series constantan resistor in the load circuit and operating voltage is sampled through a resistive subdivision network. Thus the load′s real-time active power is calculated and uploaded to the cloud server on the frequency of 1 Hz. On the side of cloud server, features extraction and dimensionality reduction are processed by PCA. The running load is classified by kNN. Users can visit the load monitoring interface by terminal devices. In the experiments, the system is installed in the wall socket to monitor and identify eight types of household appliances. Multiple experimental results show that the average rate of identification is above 98%, which verifies that the method proposed is accurate and feasible.
Key word:
power measurement
load identification
cloud server

Design of intelligent unmanned vending system in machine vision


Author:Lin Fuchun,Zhang Rongfen,He Qianqian,Liu Yuhong

Author Affilications:College of Big Data and Information Engineering,Guizhou University,Guiyang 550025,China

Abstract:This paper proposes an intelligent automated vending system based on machine vision and deep learning. The embedded ARM9 and various sensors are used to form the front-end acquisition system. The trained convolutional neural network is used to detect and identify the goods dynamically and statically on the server. Then the identifying information will be fed back to the databases, and the databases will integrate all the information. Finally it will determine the order information of customers. This system uses front-end hardware to acquire images on the automated vending counter and test them on the server's Caffe framework, and the result shows that the accuracy of this system can reach 99% in real time.
Key word:
new retail
machine vision
deep learning
convolutional neural network

Communication and Network

NB-IoT physical random access analysis and receiver detection algorithm


Author:Li Xiaowen,Qu Yuanyuan,Zhou Shuqi,Mou Hongyan,Chen Qirong

Author Affilications:Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China

Abstract:NB-IoT is an emerging cellular technology that provides better coverage for applications with large connectivity,low power,low throughput,low device cost and high latency tolerance.Compared with Long Term Evolution(LTE)system,the Narrow-band Physical Random Access Channel(NPRACH)of NB-IoT system has been modified a lot.Therefore,the structure design of NPRACH in NB-IoT system is analyzed in detail by comparison with LTE system.And a 2-D FFT-based NPRACH receiver detection algorithm is proposed. Through MATLAB simulation analysis,the results show that under different coverage levels,the algorithm detects NPRACH Preamble missed detection probability of less than 0.05% Misdetection Probability(MDP),Alarm Probability(FAP)less than 0.1%, which meets the standard requirements of 1% MDP and 0.1% FAP indicator,and the probability of Time-of-arrival(ToA) Error in the range of -2.5~2.5 μs is higher than 95%.
Key word:
random access

Design and implementation of ADS-B data packet collection and analysis system


Author:Suo Guowei,Wang Jinsuo,Guo Ronghua,Zhao Pan

Author Affilications:Chinese Luoyang Electronic Equipment Center,Luoyang 471003,China

Abstract:The amount of information contained in the typical Automatic Dependent Surveillance-Broadcast (ADS-B) terrestrial station system is often small,and it does not support the real-time collection of the flight target track data packets, the dynamic display of track information at the data level, and the more granularity of the historical playback of raw data packets. For these practical application needs,this article aims to build a set of ADS-B data packet collection and analysis system, and try to optimize the processing applications of the acquired messages after processing the host by the ADS-B ground station,designing the data collection method of ADS-B Category(Cat) 021 packet, using UDP multicast to connect externally to Cat 021 packet parsing module. According to the standard Cat 021 data packet protocol format, a corresponding message parsing algorithm is designed and implemented to parse and store the collected data messages in real time.
Key word:
Cat 021
data collection
packet analysis

Uplink pilot design based on frequency offset and IQ unbalance estimation


Author:Zhang Jiali,Shi Yuanyin,Wang Xuanhong

Author Affilications:School of Communication and Information Engineering,Xi′an University of Posts and Telecommunications,Xi′an 710121,China

Abstract:In order to solve the problem that the IQ imbalance and carrier frequency offset cause a sharp increase of BER in OFDM system, a pilot signal design compatible with DMRS signal of uplink LTE is proposed. The pilot signal can replace the DMRS signal for channel matrix estimation, and also can realize frequency offset estimation and IQ unbalance parameter estimation,which improves the tolerance of the system to IQ imbalance and carrier frequency offset without increasing pilot overhead and system complexity. The simulation results show that the pilot signal can not only accurately estimate the frequency offset and IQ unbalanced parameters, but also achieve a good frequency domain equalization effect.
Key word:
frequency offset estimation
IQ imbalanced
channel estimation
uplink LTE

Multicast routing protocol for MANETs based on fuzzy logic


Author:Yang Hongpei1,Liu Ping2

Author Affilications:1.Department of Information Engineering,Xuchang Electric Career Academy,Xuchang 461000,China; 2.School of Computer and Information Engineering,Henan Normal University,Xinxiang 453000,China

Abstract:In order to solve the unstable routing problem of multicast routing caused by insufficient energy, a multicast routing protocol based on fuzzy logic is proposed. This protocol firstly establishes a multicast mesh and then uses fuzzy logic to select the multicast routes. In the multicast routing selection stage, two parameters of energy and distance of the nodes are used as the basis for route evaluation. Fuzzy logic is used to establish the fuzzy relation between energy and distance of nodes and route quality. The Gaussian membership function is used to execute fuzzification of input parameters. The centroid method is used to execute defuzzification of output parameter, which is used for select best multicast routes. The simulation results show that, compared with the existing multicast routing protocols, this protocol has higher packet delivery rate and lower end-to-end average delay.
Key word:
multicast routing
mobile ad hoc networks
fuzzy logic
fuzzy inference
Gaussian membership function

An precoding method based on two-sided Jacobi SVD in MIMO PLC system


Author:Lin Huan1,Li Xiang2

Author Affilications:1. School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications, Chongqing 400065,China; 2. Key Lab of New Generation Broadband Mobile Communication Technology, Chongqing University of Posts and Telecommunications,Chongqing 400065,China

Abstract:In recent years, the MIMO technology has been paid extensive attention in the field of power line communication, which can enhance the system bit rate and spectrum efficiency without increasing bandwidth. The complexity of the inverse operation is too high for the traditional zero-forcing algorithm , so a precoding algorithm based on two-sided Jacobi SVD is proposed to reduce the computational complexity. Firstly, the real symmetric matrix is constructed. And then,the matrix is diagonalized by two-sided Jacobi transformation. Finally,Taylor series expansion is introduced to simplify the calculation process. The simulation results show that the algorithm can effectively improve the bit error rate performance without loss of calculation accuracy.
Key word:
power line communication
two-sided Jacobi

A novel unambiguous tracking method for BOC(kn,n) signals


Author:Zheng Kun,Zhang Xiaolin

Author Affilications:School of Electronic and Information Engineering,Beijing University of Aeronautics and Astronautics,Beijing 100191,China

Abstract:Binary Offset Carrier(BOC) modulated signal’s autocorrelation function(ACF) has multiple side-peaks, which will cause the ambiguous problem in tracking process. Focusing on this problem, a novel unambiguous tracking method for BOC(kn,n) signals is proposed. In this method, two local BOC-Like auxiliary signals are designed to synthesize correlation function with no side peaks, and the receiver uses a delay-locked loop(DLL) based on this correlation function to eliminate the tracking ambiguity of the BOC modulated signal. Theoretical analysis and simulation results show that the improved correlation function can completely eliminate side peaks and make the main peak sharper. Meanwhile, the discriminator output curve based on this method can eliminate the original false lock point and enhance the anti-noise and multipath mitigation performance of the tracking loop.
Key word:
unambiguous tracking
multipath mitigation

Computer Technology and Its Applications

Design and implementation of multi-channel high-speed data security transmission system


Author:Li Junhao,Bi Lixia,Wang Yongli

Author Affilications:National Computer System Engineering Research Institute of China,Beijing 100083,China

Abstract:Aiming at the problem of low rate and poor security in general data transmission system, a multi-channel high-speed data security transmission system scheme is proposed. In this scheme, CPU is used as the control center, FPGA and high-speed serial transceiver TLK2711 are used for high-speed data security transmission in four-channel. To test and verify the feasibility of the scheme,the multi-channel high-speed data transmission system hardware platform is built. The experimental results show that the highest transfer rate in this system can up to 4.8 Gb/s.
Key word:

Research of software time synchronization project on Kylin operating system


Author:Li Yonggang1,Li Xinquan2,Guo Libing1,Li Xiangming1,Mao Wen1

Author Affilications:1.China Satellite Marine Tracking and Controling Department,Jiangyin 214431,China; 2.China Aerospace Engineering University,Beijing 101400,China

Abstract:The development of homemade computer system of measurement and controlling becomes quickly, but the research of software time on Kylin is still on an underway phase. This paper puts forward the software time project, and tests the performance. The test result shows that the performance of the software time accords with the technology criterion, and the software time project supports the technology instructor of system manufacture.
Key word:
software time

The new architecture of smart wheelchair system based on UM-BUS


Author:Feng Shaohui1,2,Zhu Xiaoyan1,Zhang Weigong1,3

Author Affilications:1.College of Information Engineering,Capital Normal University,Beijing 100048,China; 2.Beijing Key Laboratory of Electronic System Reliability and Prognostics,Capital Normal University,Beijing 100048,China; 3.Beijing Advanced Innovation Center for Imaging Technology,Beijing 100048,China

Abstract:In this paper, according to the characteristics of reconfigurable high speed serial bus(UM-BUS), a new architecture of intelligent wheelchair system based on UM-BUS is proposed, which is superior to the traditional architecture in scalability and dynamic fault tolerance. Based on the new architecture, a common hardware and software platform is designed. The intelligent wheelchair control system designed in this paper has the characteristics of easy expansion, high reliability and versatility.
Key word:
reconfigurable high speed serial bus
intelligent wheelchair
easy expansion
high reliability

A new test vector optimization method for failure isolation


Author:Jiang Jueyi1,Li Fan1,Li Jianhong2

Author Affilications:1.AVIC China Areo-Polytechnology Establishment,Beijing 100028,China; 2.The 6th Research Institute of China Electronics Corporation,Beijing 100083,China

Abstract:In order to improve the fault diagnosis efficiency and shorten the fault isolation time based on the testability modeling, a test vector optimization method is proposed. Aiming at the exact detection and isolation requirements of each failure mode in the D matrix, a detailed calculation procedure of the test vector optimization is given,to obtain the test vector with the least number of tests and the shortest calculating time. Both simulation and realistic data experimental results show that the test vector optimization in this paper has fast calculation speed and good optimization effect. It is suitable for large-scale D-matrix applications and can effectively support the fault diagnosis and isolation design for complex systems.
Key word:
test vector
testability modeling
fault isolation

Power Supply Technology and Its Application

LCL filter optimal parameter selection method for grid-connected inverter


Author:He Jinyu1,Wei Jincheng1,Guo Xiaoying2,Zhang Yufeng1,Li Yiming1,Chen Limei3,Cao Taiqiang1

Author Affilications:1.School of Electric Information,Xihua University,Chengdu 610039,China; 2.School of Information and Electric Engineering,Panzhihua University,Panzhihua 617000,China; 3.Sichuan Ming Zhu Group Co.,Ltd.,of State Grid,Suining 629200,China

Abstract:The existing filter design methods only consider the filter characteristics. The influence of the change of the ratio of the two inductor parameters on the filter performance is not analyzed, and the limit about the switching frequency of the filter parameter design is also not considered.Therefore, the filter failed to achieve the best performance. In this paper, the mathematical expressions of μ(the ratio of grid side inductance to inverter side inductance) and k(the ratio of switching frequency to resonant frequency) are firstly established. Secondly, the relationship between μ, k parameters and component volume, energy storage and harmonic attenuation is studied. The range of μ、k parameters is determined.Finally, the optimal LCL filter parameters are calculated.Through the simulation, the total harmonic distortion of the single-phase grid-connected inverter is 2.02%, the power factor is 99.82%, and the load can be rapidly responded to the sudden change and the system achieves a new dynamic balance fastly.
Key word:
grid-connected inverter
LCL filter
inductance ratio
switching frequency

Application of new bidirectional DC/DC converter in uninterruptible power supply system


Author:Fang Xupeng,Zhao Yang,Yu Zhixue

Author Affilications:College of Electrical Engineering and Automation, Shandong University of Science and Technology,Qingdao 266590, China

Abstract:In order to solve the uninterruptible power supply in the power flow of the uneven distribution and raising and reducing capacity problems, based on the bidirectional Buck-Boost DC/DC converter on the traditional topology from begin to research, a new type of bidirectional DC/DC converter is put forward. By analyzing the circuit topology and working principle of the converter, two operating modes of power forward transmission and reverse transmission are introduced in detail, and the output voltage expressions corresponding to different modes are derived. Compared with the conventional bidirectional Buck-Boost type DC/DC converter, the new bidirectional DC/DC converter proposed in this paper has higher voltage gain, smaller power switching voltage stress, and more stable output voltage. Finally, the feasibility and advantages of the new topology are verified by theoretical analysis and experimental circuit.
Key word:
uninterruptible power system
bidirectional DC/DC converter
voltage gain
switching voltage stress

New double input Sepic DC/DC converters


Author:Lan Zhiyong,Chen Lijun,Jiao Shi,Li Li,Wang Bo,Xu Chen

Author Affilications:Information Engineering College,Xiangtan University,Xiangtan 411105,China

Abstract:In the distributed power system with more sources, the application of multiple-input converter instead of using several single-input converters can simplify the circuit , decrease the cost of the power system, but also improve the reliability of the power system. A new double-input Sepic DC/DC converter is proposed in this paper. The proposed topology has the following advantages: the circuit is simple,the voltage gain is high, the voltage stress of the switches is low and the sources can deliver power to the load individually or simultaneously. The operation modes and the steady-state analysis are presented. Finally, the MATLAB simulation and experiments on an output power 200 W prototype verify the correctness of the theoretical analysis.
Key word:
DC/DC converter
voltage gain

Research on control strategy of VIENNA rectifier based on sliding mode variable structure and IMC


Author:Wang Xiandong,Shao Ruping,Li Yan

Author Affilications:School of Automation & College of Electrical Engineering and Control Science,Nanjing Tech University,Nanjing 211816,China

Abstract:For the VIENNA rectifier,the DC side voltage is required to be stable and have good dynamic performance and robustness.A novel nonlinear control strategy for VIENNA rectifier based on IMC and sliding mode variable structure control is proposed.According to the main circuit topology, the mathematical model of VIENNA rectifier is established and a VIENNA rectifier controller based on internal model theory and sliding mode variable structure theory is designed.The simulation and experimental verification are carried out in this paper,the simulation and experimental results show that the control strategy can achieve the purpose of control effectively, and has the characteristics of robust, fast dynamic response, strong anti-interference ability and so on.
Key word:
VIENNA rectifier
mathematical model
sliding mode control
internal mode control

Study on a new kind of control method of single-phase rectifiers


Author:Hu Xiaoxue1,Wang Haibin1,Guo Xiaoying2,Zhang Yufeng1,Liu Zhonghao1,Cao Taiqiang1

Author Affilications:1.School of Electrical Engineering and Electronic Information,Xihua University,Chengdu 610039,China; 2.School of Information and Electric Engineering,Panzhihua University,Panzhihua 617000,China

Abstract:According to these drawbacks of traditional direct power control(DPC) in single-phase PWM rectifiers such as slow dynamic response,poor anti-interference ability and variable switching frequency, an algorithm based on outer loop adopting the feedback of capacitor energy storage and internal loop with deadbeat predictive direct power control is further given.This algorithm improves the speed of dynamic response and the ability of anti-interference with the outer loop control method based on the feedback variable of capacitor energy storage and load power feed forward. Meanwhile,the auto-regressive algorithm simplifies the controller design, and addresses the issue of delay compensation in traditional control. Combined with the space vector modulation(SVPWM) the system′s switch frequency is fixed. Furthermore, it reduces the design costs without voltage′s phase detector. Finally, the proposed control method and traditional DPC method were compared in computer simulation respectively , and the simulation result verified the validity of the proposed control method.
Key word:
deadbeat predictive control
direct power control
capacitor energy storage
space vector

The research and application of LLC resonant converter in two-stage charger


Author:Lin Yuting,Cao Taiqiang,Chen Yufeng

Author Affilications:School of Electrical Engineering and Electronic Information,Xihua University,Chengdu 610039,China

Abstract:Aiming at the low power density, low charging efficiency and input current harmonic content of traditional electric vehicle charging machine, a new topology structure is adopted in this paper. The former stage adopts two-stage staggered parallel Boost PFC circuit, which can effectively improve the power density of the former converter and reduce the THD value of the input current. The rear stage adopts the semi-bridge LLC resonant circuit to improve the power density and charging efficiency of the rear converter. The working principles of the two-level staggered parallel Boost PFC and the half-bridge LLC resonant converter are analyzed. The fundamental wave analysis method(First Harmonic Approximation,FHA) is used to do LLC resonant network modeling, and on this basis it determines the scope of switching frequency and the optimum working range. The simulation and experiment validate the correctness of the mathematical model and parameter design. Finally, a charger is designed whose input voltage is 175 V~265 V, and maximum output power is 1.5 kW. The experimental results show that the front-end converter power factor is 0.996, the input current THD is 4%, and the machine efficiency can reach 94%.
Key word:
Boost PFC
LLC resonant converter