最新刊期
卷 ， 期 3 ， 2019
- 摘要：The paper proposes a scientific and reasonable 5 G end-to-end application scenario prediction method, and evaluates several applications that may become killer in the future. Different from the simple summary of some 5 G segmentation scenarios in the industry, the article uses the three interconnections in the 5 G era, three technical scenarios and five major industry categories as the basis for judgment. The paper also establishes theoretical support and credible application system evaluation and forecasting standards. And for some industries to apply "pain points", the paper explains the corresponding specific meaning, key performance indicators, related scenario cases and future ideas. It is expected to find key applications that will have a huge contribution and influence to the country, society and individuals in the future.关键词：5G;killer application;End-to-End applications;assessment and prediction mechanism;three interaction relations;application system
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发布时间： - 摘要：In the medium and short code lengths, the performance of the polar code without Cyclic Redundancy Check（CRC） assistance is not competitive. In order to increase the decoding performance of the polarization code, CRC assisted decoding is generally used. For the traditional centralized CRC auxiliary scheme, the path can only be selected after the end of decoding and cannot be pruned in the decoding. This paper proposes an auxiliary decoding scheme for discretely allocating CRC bits between the bits of the polar code information through the interleaver. The scheme allows the CRC bits to assist in the selection of survivor paths during Successive Cancellation List（SCL） decoding process to improve the error performance. Simulation results show that compared with the centralized CRC-assisted decoding scheme. Simulation results show that compared with the centralized CRC-assisted decoding scheme, when the code rate is 0.125、block error rate is 10-1, the algorithm provides 0.5 and 1.3 dB gain while the length of CRC is 8 and 16 bits respectively.关键词：polar code;SCL;CRC;interleave
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- 132
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发布时间： - 摘要：In order to improve the indoor positioning accuracy and realize three-dimensional positioning, this paper proposes an indoor reverse positioning system using a single Light Emitting Diode（LED） lamp. This positioning system solves the problem of interference in positioning by using multiple LED light sources. The system takes the white LED light used by people in daily life as the light source, which is not only consistent with the actual situation, but also convenient for future promotion. The system estimates the distance according to the illuminance received by the receiver, and fits the optimal regression curve with the minimum residual sum of squares as the objective function. Then we use the triangulation principle and the spatial geometric relationship to determine the receiver coordinates. The experimental results show that the positioning system can realize accurate indoor positioning service in practical application scenarios.关键词：LED;indoor positioning;light;localization algorithm
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- 514
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- 1
发布时间： - 摘要：With the development of smart grids, high requirements are placed on distribution networks. Distribution network communication systems are an important part of distribution networks and an important factor affecting the development of distribution networks. Improving the terminal online rate is the key to the stable operation of the distribution network communication system. Due to the access mode and management issues, it affects the online rate of the terminal equipment and restricts the development of the distribution network. This paper discusses the terminal online rate drops from the aspects of terminal access mode and management, optimizes the terminal access mode and proposes the management method for the distribution network communication system, which improves the terminal online rate, and the stability of distribution network communication system, and promotes intelligent matching power grid development.关键词：smart grid;distribution network;ethernet passive optical network;optical communication system
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- 140
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- 1
发布时间： - 摘要：Polarization-Maintaining Fiber（PMF） is the core component of fiber optic gyroscope. Due to the high requirement of precision and miniaturization in fiber optic gyros, the outer dimensions of optical fibers are decreasing. As fiber geometries continue to shrink, how to reduce the fiber’s outer diameter while maintaining the fiber’s superior performance becomes a major challenge in fiber design and manufacturing. In this paper, the 60/100 μm PMF technology is studied, and the reliability of the developed product is analyzed.关键词：slim diameter;PMF;60 μm
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- 200
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发布时间： - 摘要：As one of the core devices of optical communication system, the performance of photodetectors plays a decisive role in evaluating the system performance. With the rapid increase of optical communication data, the traditional photodetectors can not meet the demand. This paper presents a high performance silicon based germanium uni-traveling-carrier photodetector integrated with Si3N4 waveguide. With the help of the software of Lumerical FDTD and DEVICE for modeling and simulation, the waveguide structure and the size of photodetector are designed. Finally, the optimized structure could achieve optical responsivity of 0.97 A/W at 1 550 nm wavelength and-1 V bias, with linear output photocurrent greater than 30 mA and electrical 3 dB bandwidth up to 28 GHz.关键词：optical communication;Si3N4 waveguide;silicon based germanium;Uni-Traveling-Carrier PhotoDetector（UTC-PD）
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- 298
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- 3
发布时间： - 摘要：Aiming at the problem of easy oxidation of metal film on the outer surface of Photonic Crystal Fiber（PCF） refractive index sensor, a new structure of PCF refractive index sensor is proposed. The air holes of the PCF are arranged in a spiral track. Double coating is on the outer surface of the PCF. The silver is coated on the outer surface of the PCF as a Surface Plasmon Resonance（SPR） material, and a 15 nm thin ZnO film is coated on the silver film to prevent the metal from being oxidized. The properties of this sensor is analyzed by the full vector finite element method with the boundary condition of anisotropic perfectly matched layer. Results show that the maximal sensitivities of the sensor reach 5 200 nm/RIU and the resolution reach 1.92×10-5 RIU when refractive index is in the range of 1.30 to 1.36.关键词：full-vector finite element method;PCF;surface plasmon resonance;double layer coating;refractive index
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- 331
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发布时间： - 摘要：In order to improve the surface temperature uniformity of thermally tuned etalon for external cavity tunable laser, the surface temperature distribution of etalon is obtained by simulation analysis. In order to achieve the purpose of homogenizing the surface temperature distribution of thermal tuning etalon, this paper proposes a solution of optimizing the heating electrode of etalon. This paper first describes the solutions by the optimal trajectory distribution of heating electrode, the increase of thermal resistance and the power distribution of heated electrode. The surface temperature distribution is obtained by the thermal analysis of the optimized thermal tuning standard after the optimization of the thermal tuning etalon. The results show that the surface temperature difference of etalon after optimizing thermal tuning etalon can be reduced by 77%, and the temperature uniformity of optimized thermal tuning etalon is better. In addition, the influence of the surface temperature difference on the wavelength stability is greatly reduced,and the effect of surface temperature uniformity of the etalon on the wavelength stability of the laser is verified by experiments.关键词：laser;tunable laser;thermally tuned etalon;thermal analysis;optimal design
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- 90
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发布时间： - 摘要：In the traditional micro-ring electro-optic switch structure, the function of switching in optical communication system is realized by designing different positions between micro-ring and direct waveguide. However, the switching voltage is so high that it wastes resources. Based on the coupled mode theory, electro-optic modulation theory, micro-ring resonance theory, and transfer matrix theory, a device model of nested micro-ring dual-channel electro-optic switch is proposed in this paper. We conduct a simulated analysis of this device at the resonant wavelength of 1 552 nm. The simulation results show that the device model has a very small switching voltage of only 1 V with crosstalk less than-35 dB and insertion loss less than 4 dB. The total time domain response is 5.33 ps with rise and fall time of only 0.25 ps. The structure has the characteristics of low switching voltage, short response time and large spectral bandwidth, which enhances the performance of dense wavelength division multiplexing system.关键词：fiber optics;nested micro-ring;electro-optic switch;operation voltage;time response
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- 58
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发布时间： - 摘要：The annual shipment of semiconductor detectors of the coaxis Transistor Outline（TO） packaging type is as high as tens of millions. Therefore, the quality control and testing are very important. Traditional manual visual inspection with microscope has a high rate of false detection and missed detection because of the influence of subjective judgment and visual fatigue. To solve this problem, this paper proposes an Automatic Optical Inspection（AOI） scheme for the appearance of coaxial semiconductor detectors. The visual inspection is used to automatically identify and classify qualified products and non-conforming products. The depth of field synthesis technique is used for the height detection of wire arcs. The test results of the prototype show that the proposed scheme has good detection adaptability and low false detection rate, which is suitable for batch inspection task of production line and can replace manual visual inspection.关键词：coaxial TO semiconductor detector;visual detection;field depth synthesis;AOI
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- 103
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- 1
发布时间： - 摘要：In the ultra-dense network scenario, a power allocation scheme based on the utility function optimization model is proposed to maximize the sum rate of user-centric overlapped virtual cell systems. The optimal power allocation is obtained based on the hierarchical alternating iterative algorithm. Firstly, the original problem is decomposed into two sub-problems: power splitting and virtual power allocation. Secondly, an optimal power splitting algorithm based on equilibrium strategy is obtained by introducing the Lagrangian function at the upper layer, and further power allocation is achieved by using the virtual power at the bottom layer. Since the power splitting coefficient takes the form of eigenvector which maximizing Signal to Leakage plus Noise Ratio（SLNR）, a balanced effect on signal enhancement and interference reduction is achieved. Simulation results show that the proposed algorithm is superior to conventional power allocation algorithms in performance, which can effectively reduce the interference and increase the sum rate of the system.关键词：ultra-dense network;power splitting;hierarchical iteration;interference coordination
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- 87
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发布时间： - 摘要：Compared with Long Term Evolution（LTE）, cell search based on 5 G, the applications of high frequency band scenarios are included and the synchronous signals are redefined. In this paper, the Primary Synchronization Signal（PSS） in 5 G system is analyzed in detail, and the new contents are studied. A timing synchronization algorithm for the PSS in 5 G system is proposed. Among them, a differential synchronization algorithm with good anti-frequency offset performance is proposed for coarse synchronization, and a low-complexity synchronization algorithm is proposed for fine synchronization based on the conjugate symmetry of PSS sequence. Simulation results show that, even under the influence of high frequency bias, the algorithm can quickly and correctly lock a coarse synchronization point, which is less affected by frequency offset. From the perspective of computational complexity, the calculation amount of the algorithm is 17.69% of that of the conventional algorithm.关键词：5G new radio;PSS;cell search
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- 408
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发布时间： - 摘要：Non-Orthogonal Multiple Access（NOMA） is a basic support technology for the 5 G wireless networks. It can meet the heterogeneous requirements of large-scale connectivity and high throughput with increasing number of access subscriber. The key idea of NOMA is that the same resource block provides services for multiple users. The supported number of users can be increased. However, the upgrade of system capacity is limited. To solve this issue, the paper combines NOMA technology with massive Multiple-input Multiple-output（MIMO） antenna to improve the capacity of the system. At the same time, the downlink multi-users perform user matching according to channel differences, and the two are divided into one cluster. Block Diagonalization（BD） algorithm is used to eliminate the interference between the clusters. The interference between users in the cluster is eliminated by serial interference. The simulation results show that the BD precoding at the transmitter side can reduce the interference received by the terminal. The system capacity based on NOMA technology combined with massive MIMO is greatly improved. The system performance can be further improved when user matching grouping is performed on this basis.关键词：NOMA;massive MIMO;user matching;BD algorithm
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