Special Column-Expert Forum

Key technology research and product development of 5G test instruments


Author:Liu Zushen1,2

Author Affilications:1.The 41st Institute of CETC,Bengbu 233010,China; 2.China Electronics Technology Instrument Co.,Ltd.,Qingdao 266000,China

Abstract:With the promotion of 5G technology R & D tests and product R & D tests, as a support of the development of the industry, the test instruments have entered the fast development track. Domestic manufacturers have successfully developed 5G communication test instruments such as base stations, terminals, outfields and core networks. This article introduces the key technology breakthroughs and latest product achievements of 5G communication test instruments, including high-performance 5G communication test platform design and manufacture, multi-standard 5G NR physical layer test, 5G heterogeneous network air interface protocol analysis, microwave and millimeter wave test and calibration and other key technologies, also introduces the performance of test instruments such as base station test, terminal comprehensive test and air interface monitoring. These test instruments are important in every link of 5G communication industry chain, and provide strong support for the rapid development of the industry.
Key word:
5G test
EVM calibration
new air interface
base station radio communication tester
terminal radio communication tester

Special Column-5G Co-construction and Sharing Technology

Research on the evolution of 5G NSA radio access network sharing


Author:Gao Qian,He Lin,Li Fuchang,Zhu Xuetian,Feng Yi

Author Affilications:China Unicom Network Technology Research Institute,Beijing 100048,China

Abstract:There are more and more mobile operators had launched 5G services in 2019, 5G is entering a critical period of commercial deployment globally. Considering the maturity of SA standards, equipment and terminals, 5G shared network is based on the NSA architecture in the initial stage of 5G deployment, so the operators need to consider evolution towards SA phase in order to ensure that the network sharing would last throughout the 5G life cycle. This paper systematically analyzes different evolutions from network complexity, operation and maintenance optimization complexity, user experience and so on, in order to provide an effective guideline for operators to choose the evolution for RAN sharing.
Key word:
5G network
RAN sharing

Research on co-construction and sharing based on core network roaming


Author:Xia Xu1,Wang Hui2,Xu Dai2

Author Affilications:1.China Telecom Research Institute,Beijing 102209,China;2.ZTE Corporation,Shenzhen 518057,China

Abstract:In order to save the construction and operation costs of 5G network, many operators actively promote the co-construction and sharing of 5G infrastructure, but the advanced technology and diversified deployment bring challenges to the implementation of the co-construction and sharing of 5G network. While introducing the 5G co-construction and sharing technology, this paper focuses on two different 5G networking scenarios and then elaborates on the roaming technology scheme of core network and discusses the solutions to network co-construction and sharing in the 5G era.
Key word:
core network

Comparative study on 5G network sharing technology scheme


Author:He Lin,Zhou Yao,Zhu Xuetian,Li Fuchang,Feng Yi

Author Affilications:China Unicom Network Technology Research Institute,Beijing 100048,China

Abstract:The 5G network requires large construction investment and high operation cost, there is a large pressure on 5G industrial income. In order to lower down the cost of network construction and operation, and implement the new idea of “innovation, coordination, green, open, sharing”, more and more operators focus on 5G network sharing which can realize fast service capabilities by efficient network coverage. In this paper, the technology of 5G network sharing will be analyzed thoroughly including basic principle, user experience, impact on the network and potential risk in order to provide some useful reference to operators.
Key word:
5G network sharing
inter-networks roaming
radio access network sharing

Review and Comment

Overview of field effect transistors based on Ga2O3


Author:Gao Cancan1,Ma Kui1,2,Yang Fashun1,2

Author Affilications:1.College of Big Data and Information Engineering,Guizhou University,Guiyang 550025,China; 2.Semiconductor Power Device Reliability Engineering Research Center of Ministry of Education,Guiyang 550025,China

Abstract:As the third-generation wide bandgap semiconductor material, gallium oxide(Ga2O3) has been widely used in high-power devices and other fields due to its advantages such as ultra-wide band gap, high breakdown field strength and high BFOM. Hotspots of research by researchers at home and abroad.This paper mainly introduces the characteristics of Ga2O3 materials, summarizes the research progress of field-effect transistors(FETs) based on Ga2O3, and summarizes the development of Ga2O3 power devices.
Key word:
wide bandgap semiconductor
field effect transistor

Artificial Intelligence

A similarity measurement method for science and technology project text


Author:Zhao Xiaoping1,Ma Wen1,Liu Xueping2,Chen Da2

Author Affilications:1.Information Center,Yunnan Power Grid Co.,Ltd.,Kunming 650011,China; 2.Yunnan Yundian Tongfang Technology Co.,Ltd.,Kunming 650220,China

Abstract:Existing text similarity measurements often use the TF-IDF method to model texts as term frequency vectors without considering the structural features of texts. This paper combines the structural features of texts with the TF-IDF method and proposes a text similarity measurement for science and technology project texts. This approach firstly pre-processes a text and extracts module texts according to its structural features. After applying the TF-IDF method to these extracted module texts, this method extracts the top keywords of each module text, obtains its feature vector representation, and finally uses cosine formula to calculate the similarity of two texts. By comparing with the TF-IDF method, experimental results show that the proposed method can promote the evaluation metrics of F-measure.
Key word:
text similarity
text clustering
natural language process

Disguised face recognition based on deep neural network


Author:Zhang Runsheng1,2,3,He Chao1,2,3,Kuang Chaoqing1,2,3

Author Affilications:1.School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications, Chongqing 400065,China; 2.Optical Communication and Networks Key Laboratory of Chongqing,Chongqing 400065,China; 3.Ubiquitous Sensing and Networking Key Laboratory of Chongqing,Chongqing 400065,China

Abstract:Camouflage face recognition has great application value in the field of criminal investigation and security. Aiming at the shortcomings of few researches on camouflage face recognition and weak robustness at present, a camouflaged face recognition algorithm based on deep neural network is proposed. The SqueezeNet network model has been improved and combined with the FaceNet network architecture for identity recognition of face images. By adding camouflage face images in the training data set, the network can learn the characteristics of the camouflages. The experimental results show that the recognition accuracy of the algorithm is close to 90%, which is better than other network models.
Key word:
deep neural network
disguised face recognition
SqueezeNet network model
FaceNet network architecture

Microelectronic Technology

Design of custom CPU architecture based on FPGA


Author:Li Jun1,Ren Lianxin2,Liao Zhenxiong3

Author Affilications:1.Shenzhen Co-trust Technology Limited Company,Shenzhen 518055,China; 2.College of Automation Science and Engineering,South China University of Technology,Guangzhou 510640,China; 3.Shenzhen Kechuangsi Technology Limited Company,Shenzhen 518055,China

Abstract:In order to meet the needs of more and more distributed computing in current industrial applications, this article proposes a way to build a custom instruction set CPU in an FPGA chip. In this way, the FPGA has the ability to process instructions similar to a microcontroller. Moreover, the premise of this capability is the reuse of computing units, so resource consumption is limited and will not increase as the amount of calculation increases. In the improved architecture of the custom instruction set CPU, a parallel computing structure is used, which greatly improves the operation speed. Finally, combining the actual application case, the FOC algorithm in the current loop calculation is transplanted to the operation in the custom CPU. And ModelSim software is used to simulate, its calculation time is only 7.48 μs.
Key word:
custom instruction set
CPU architecture
parallel computing structure

Design and implement of a ring-VCO based PLL with wide frequency range and low jitter


Author:Liu Ying1,Tian Ze1,2,Lv Junsheng1,2,Shao Gang1,2,Hu Shufan1,Li Jia1

Author Affilications:1.AVIC Computing Technique Research Institute,Xi′an 710068,China; 2.Aviation Key Laboratory of Science and Technology on Integrated Circuit and Micro-System Design,Xi′an 710068,China

Abstract:A ring-VCO based phase lock loop(PLL) is designed for achieving the wide frequency range and low jitter requirements of high speed communication system. By adjusting the loop bandwidth which is closely related to the lock-in frequency it reduces the loop noise and accelerates loop locking. Adopting the comparator in reference circuit to compare the locking control voltage with the reference voltage to flexibly change the current in other module, and adjusting the loop parameters according to different lock-in frequencies, the lock-in time is greatly reduced. At the same time, the differential symmetrical structure of the four-stage differential ring oscillator and duty cycle adjusting circuit is used to reduce the circuit noise. This chip is fabricated in 40 nm CMOS process, the measured results show that the output frequency is from 1.062 5 GHz to 5 GHz, the performance of the signal at 5 GHz is good and jitter is 39.6 ps.
Key word:
phase lock loop
ring oscillator
wide frequency range
low jitter

Design and verification of RISC-V processor with three-stage pipeline


Author:She Ruyi1,Li Binghui2,Jiang Peihe2

Author Affilications:1.Department of Science,Hetao College,Bayannur 015000,China; 2.School of Opto-Electronic Information Science and Technology,Yantai University,Yantai 264005,China

Abstract:As an open source reduced instruction set architecture, RISC-V gained a lot of attention since its release. A three-stage pipelines RISC-V processor is designed. Back taken forward not taken(BTFN) is used to handle branch situation in pipeline execution. Bypass and forward technology is used to solve data risk. At the same time, the method of resource sharing is adopted, and the modules such as general register heap, adder and selector are reused to optimize the design area. In the EDA tools, simulation is carried out using the RV32I integer arithmetic instruction set. The result shows that the designed processor works correctly and achieves the predetermined goal.
Key word:
RISC-V instruction set

Measurement Control Technology and Instruments

Design of visualized intelligent detection device for portable electric well


Author:Huang Zhenxi,Huang Yibiao,He Shuhua,Chen Xiangwei,Wang Huayan,Liu Haolin,Xiao Zhenyin

Author Affilications:State Grid Fuzhou Power Supply Company,Fuzhou 350009,China

Abstract:In order to improve the safety of underground power operations,it is especially important to overhaul the power underground to contain toxic gases and flammable and explosive gases. This paper designs a portable electric power well visualized intelligent detection device. The operator can panoramically photograph the cable equipment in the power well on the ground,and simultaneously detect the harmful gas content in the underground. The design adopts a high-definition rotating camera to perform shooting, and the detection equipment is equipped with gas concentration. And the type detection and identification device can collect and display data and display alarms in real time. It is verified by experiments that the intelligent detection device has important application value for power cable and downhole gas concentration monitoring and improving power maintenance efficiency.
Key word:
power well
cable overhaul
intelligent detection device
gas detection

Monopulse radar velocity measurement function optimization method based on error energy discrimination


Author:Cheng Wangdong

Author Affilications:Nanjing Research Institute of Electronics Technology,Nanjing 210039,China

Abstract:In this paper, the principle of monopulse radar velocimeter system is described, and the criterion of energy discrimination based on frequency discriminator output signal is put forward because of the phase jump of echo signal, which leads to the broadening of spectrum, the occurrence of error line and the error of velocity measurement. By discriminating the output signal of the frequency discriminator, when the phase of the echo signal continues to jump, the output of the discriminator oscillates, the output of the integrator will exceed the threshold, and the speed measuring system will eliminate blurring again. When the phase of the echo signal is stable, the speed-measuring result can be returned to the correct result, so that the speed-measuring error caused by the jump line can be corrected.
Key word:
monopulse radar
velocity measurement
I/Q signal

Communication and Network

Design of small high-gain circularly-polarized microstrip antenna array for satellite communication system


Author:Jin Yuting,Xing Sirui,Sun Wei

Author Affilications:Chang Guang Satellite Technology Co.,Ltd.,Changchun 130000,China

Abstract:A novel small high-gain circularly polarized microstrip antenna array is designed for satellite X-band communication system. The square antenna cell is fed by side-feed, circular polarization is realized by using corner cutting and miniaturization is realized by slotting technology. Multi-layer feeding network is used for antenna arrays in order to match impedance, the circular distribution of multiple cells achieve good performance including miniaturization of size and optimal radiation performance. Based on the above aspects, an antenna array with 8 microstrip cells is simulated and optimized by simulation software, results show that the antenna array has the return loss under -25 dB at the center frequency 8.2 GHz, the 10 dB-bandwidth of 2.6%, the gain of 16.2 dB, the half-power bandwidth of 23.6°, and the axis ratio of 1.65 dB. The measured results and the simulation results match well. The antenna has certain guiding significance for the design of X-band wireless communication system.
Key word:
microstrip antenna

The technology of cooperative spectrum sensing in cognitive radio


Author:Nie Huifeng1,Xu Shenghai2

Author Affilications:1.The 723 Institute of CSIC,Yangzhou 225001,China; 2.Military Representative Office of the PLA Navy Force in Yangzhou,Yangzhou 225001,China

Abstract:The lack of spectrum resources is a difficult problem in the communication field.An effective method to alleviate the shortage of spectrum resources is spectrum sensing technology,which can realize the dynamic utilization of spectrum and improve the utilization of spectrum. Firstly, this paper introduces three single-user spectrum sensing techniques:energy detection method,matched filter detection method and cyclostationary characteristic detection method.Then,the system structure and perception model of cooperative spectrum sensing technology are studied.Finally, the cooperative spectrum sensing of the "K-N" fusion criterion based on energy detection method is simulated,the simulation results show that cooperative spetrum sensing performance is optimal when K=[N+1/2].
Key word:
cognitive radio
cooperative spectrum sensing
detection probability
false detection probability

Computer Technology and Its Applications

Research on vehicle identification technology based on deep learning


Author:Ma Xiu1,Tan Fukui2,Li Zhen1,Li Liangrong1

Author Affilications:1.School of Big Data and Information Engineering,Guizhou University,Guiyang 550025,China; 2.Department of Physics and Electronic Science,Xingyi Normal University for Nationalities,Xingyi 562400,China

Abstract:Vehicle recognition technology plays an important role in intelligent transportation system. This paper studies a vehicle recognition algorithm based on fast RCNN.Firstly, image detection is carried out through the target detection network, and feature extraction is carried out by using the convolution feature.Then, based on the fast convolutional neural network of frame region, the vehicle is precisely detected and the target region is segmented. Finally, based on Softmax-SVM integration model, the identification of vehicle models is realized.Experiments show that the proposed algorithm can reduce the multiplicity of calculation and improve the accuracy, sensitivity, specificity and precision.
Key word:
rapid RCNN
model identification
recognition rate

Hardware design of APF based on DSP-FPGA


Author:Song Lianqing,Wan Zhuo,Wei Xinlei,Quan Ce,Ma Cunle

Author Affilications:Telecommunications College,Xi′an Polytechnic University,Xi′an 710048,China

Abstract:APF based on NPC three-level topology structure can effectively improve the voltage withstand capacity of the switch. Firstly, through MATLAB simulation, it is concluded that three-level APF active filter has relatively good compensation characteristics in terms of harmonic current compensation.According to the conclusion of the simulation, based on the main control prototype of dual-core DSP28377D and EP3C40Q240C8N, after the design of the protection circuit, the hardware circuit of APF active filter is tested by sampling, drive test, DC side charge test and inverter side test with pure resistance inductance load.The test of hardware circuit shows that APF active filter design based on DSP-FPGA can satisfy the condition of harmonic current compensation.
Key word:
three level topology
active filter
harmonic current compensation

Cooperative reconnaissance and location algorithm of UAV cluster based on TDOA and FDOA


Author:Lv Jie,Yang Mei,Du Jing

Author Affilications:School of Aviation Foundation,Naval Aeronautical University,Yantai 264000,China

Abstract:In our country′s marine target reconnaissance and surveillance, UAV positioning technology has the advantages of good flexibility and large positioning range, but in the multi-UAV group coordinated positioning, there are still some problems, such as low positioning accuracy, low efficiency of dynamic route planning and so on.In order to improve the positioning accuracy of UAV fleet, effectively compensate for the blind areas of satellite and radar reconnaissance, and enhance the ability of target reconnaissance and surveillance at sea, this paper studies the cooperative positioning of multiple UAVs and dynamic route planning based on the results of time difference and frequency difference processing of passive signals, and simulates and verifies the model and error analysis. The prospects of cooperative positioning and reconnaissance of multiple UAVs are presented.
Key word:
unmanned aerial vehicle(UAV)
time difference of arrival(TDOA)
frequency difference of arrival(FDOA)
cooperative positioning

Embedded Technology

The design of telecommunication terminal for 1.8 GHz power wireless private network


Author:Wang Yundi1,Wang Xingtao1,Wu Qing1,Fu Haixuan1,Wu Zhanxia2,Lv Yuxiang3

Author Affilications:1.State Grid Information & Telecommunication Group Co.,Ltd.,Beijing 102211,China; 2.China Gridcom Corporation,Limited,Shenzhen 518000,China;3.Anhui Jiyuan Software Co.,Ltd.,Hefei 230088,China

Abstract:The construction of ubiquitous power Internet of things is the core task of the strategic target of state grid corporation. The power wireless private network is the important wireless access network. The 1.8 GHz power wireless private network has the characteristics of high bandwidth, strong carrying capacity, etc., which can meet the needs of power business. The telecommunication terminal is the necessary communication device of edge equipment in ubiquitous power Internet of things. According to the power consumption information collection, this paper designed the system architecture, hardware, and software, and developed the embedded telecommunication terminal. The pilot verification was conducted to test the business suitability and functionality. The results showed that the terminal can bearer the power consumption information collection business.
Key word:
ubiquitous power Internet of things
power wireless private network
power consumption information collection
telecommunication terminal
pilot verification

Design and implementation of the driver for network card plugged via UM-BUS


Author:Zhang Lin1,Zhou Jiqin1,2,Zhang Weigong1,3

Author Affilications:1.College of Information Engineering,Capital Normal University,Beijing 100048,China; 2.School of Mathematical Sciences,Capital Normal University,Beijing 100048,China; 3.Beijing Engineering Research Center of High Reliable Embedded System,Capital Normal University,Beijing 100048,China

Abstract:Dynamic reconfigurable high-speed serial bus(UM-BUS) has the characteristics of multi-channel concurrent redundancy and the ability of remote storage access. It can provide a high-speed and reliable solution for the remote access of sensors and execution units in CPS and Internet of things. This paper designs and implements a driver of network card based on UM-BUS connection, solves the problem of device access through PCIe and UM-BUS multiple buses, and realizes the driver operation of Ethernet device connected by UM-BUS. In the Linux system, the third-party network communication software is used for file transmission test. The network communication function is normal and stable, and the communication rate is basically the same as that of the standard network card, which meets the requirements of data communication between the Ethernet equipment and the external through UM-BUS in the CPS system.
Key word:
Ethernet driver
cross bus driver

Power Management

Design and simulation of one wireless power transmission system based on magnetic coupling


Author:Xiao Yahui

Author Affilications:Siemens Shenzhen Magnetic Resonance Ltd.,Shenzhen 518000,China

Abstract:In some rotating applications, the transmission of electrical energy is mostly achieved by contact-type conductive slip ring, the transmission of electrical energy in this way has shortcoming of mechanicalwear, short service life and arcing. In this paper, a device based on magnetic coupling technology is proposed to transmit electrical energy in a resonant manner, via the rectifier and high frequency inverter technology in modern power electronics technology. The circuit design, parameter calculation and simulation of the system are analyzed in detail. The results show that the system has the characteristics of simple structure, small switching loss and low noise.
Key word:
magnetic coupling
wireless power transmission
resonant circuit