Abstract：Aiming at the real-time problems of signal acquisition, attitude calculation and data output of laser gyro strapdown inertial navigation system, the data input and output of IMU, odometer, altimeter and GPS/BeiDou are analyzed. RS-232 serial interface and CAN bus interface are generally used for data exchange, which are difficult to meet the high-speed real-time sampling of sensors. The paper puts forward a high-speed data access mode of FPGA dual port RAM+dual DSP to output navigation data in real time according to the clock synchronization cycle, which can effectively solve the bottleneck problem of data transmission, processing and transmission to various devices. The highest output frequency attitude rate can reach 100 kHz~2 000 kHz, and realize the rapid response ability of attitude state of strapdown navigation system. Experiments and simulations show that this method can greatly improve the cycle calculation ability of the system and the maneuverability of the carrier.

Abstract：With the development of space technology, the technology of satellite navigation system is also improving. Inter satellite link is a wireless network with precise measurement and data transmission functions between navigation satellites. As an important means to improve the survivability of navigation system, it is very important for the construction of satellite navigation system. As an important part of inter satellite link technology, inter satellite link routing algorithm has become one of the main research fields and directions of inter satellite link technology. According to the actual operation scenario of the inter satellite link system, combined with the characteristics of the inter satellite link network, considering a variety of evaluation indexes such as data transmission delay and satellite node load, based on the idea of breadth first algorithm, supplemented by a variety of pruning strategies, this paper proposes a multi evaluation factor based routing planning algorithm. The algorithm can find the first N optimal paths in high dynamic time-varying networks. At the same time, this paper analyzes and validates the planning results of routing algorithm from many aspects, such as the number of paths between nodes, the situation of nodes building chains, the cost of path overhead and so on, so as to provide a theoretical basis for the selection of paths in the inter satellite link routing planning.

Abstract：With the development of compatibility and interoperability of global navigation satellite system, the implementation of satellite navigation receiving terminal with compatibility and interoperability performance is very important. In this paper, a dual frequency compatible and interoperable terminal is designed and implemented for CDMA navigation signal. The terminal parameters are set by terminal control software. The digital processing module is realized by general digital front-end module, parallel multi-channel acquisition based on time-domain, and multi-phase correlator, and the positioning function is further realized. The terminal has the characteristics of strong universality and fast acquisition speed, which lays a hard ware foundation for improving the continuity, integrity and availability of services.

Abstract：Galileo system provides commercial services including precise point positioning and authentication through E6B/C signals. In January 2019, the European Union announced the spreading code of the Galileo system′s E6B/C signal. This article refers to the European Union′s published document of the E6B/C signal and describes the carrier frequency, modulation scheme, primary codes, secondary codes, data coding scheme, and message structure. This article introduces the scheme of acquisition and tracking of the E6B/C signal, which acquires the E6B/C signals in the sky through the short-time correlation and FFT scheme,then uses the narrowband-wideband power ratio method and moments method to estimate the CNR of E6C and E6B.At the same time, this paper analyzes the current E6B message information that transmitted by current satellites. It shows that Galileo′s E6B signal has not yet started to provide PPP services.

Abstract：Landslide and debris flow are the most frequent deformation geological disasters in our country. It is an important safety issue to establish a high-precision, real-time and stable monitoring system. Aiming at the problem of low efficiency of the traditional GNSS-RTK landslide monitoring system as the number of observation nodes increases and the alarm leakage caused by the simultaneous displacement of the base station and observation station, a double-layer landslide monitoring system based on GNSS-RTK technology is proposed. The double-layer landslide monitoring system based on GNSS-RTK technology is proposed. On the basis of the traditional landslide monitoring system, the new system adds a micro network observation system in some important node areas, which is improved from the previous "point" monitoring to the micro area "surface" monitoring, and realizes the deformation data collection based on GNSS-RTK technology and data transmission based on Lora and LTE technology. The test results show that the data transmission is reliable and efficient, and the measurement accuracy of the system can reach millimeter level, which can meet the requirements of landslide monitoring. The density of observation nodes and the length of baseline in the micro area of the observation station can be adjusted to meet the needs of different environments.

Abstract：Since 2020，most of global main telecommunication operators have turned to 5G standalone architecture, and roll out the the commercial deployment of 5G standalone architecture. In the meantime，3GPP R16 standard which supports all 5G service scenarios was frozen. The 5G Core network needs to be upgraded and make a evolution again soon. In line with the 3GPP standard schedule and product roadmap, 3GPP R17 and R18 standard version will miss the peak period of 5G SA construction, so 3GPP R16 maybe the most nominated commerical standard version in the next 3～5 years. As a result, it is very essential to make a systematic study about 3GPP R16, especially focusing on function architecture, application scenarios and impact on network.

Abstract：In this paper, emergence background and intention of NPN are introduced, with the characteristic of two kind of NPN networks and their key technologic content. The relation between NPN and PLMN and technical requirement of NPN network entities are analysed. On the view of network deployment, comparison among Slicing, SNPN and PNI-NPN are presented, then selection of technology for private network is suggested.

Abstract：With the advancement of 5G network construction and service development, especially the development of network slicing towards convergence, diversification and intelligence in vertical industry-oriented application scenarios, new requirements are placed on the service functions of 5G network slicing. In order to adapt to the business needs of the 5G era, create 5G differentiated SLA advantages, and fully leverage the value of operators in the 5G era, this paper presents technical research and capability validation on 5G network slicing, service level guarantees and application practices. At the same time, based on the progress of 5G Stand Alone(SA) standards, key network slicing technologies were discussed, 5G business forms were refined, and new business models were simultaneously explored, providing technical optimization and support for the full-scale commercial implementation of 5G SA.

Abstract：In 3GPP release 15, service-based architecture work item mainly finished the mechanism of service discovery. However, communication between network functions is still in a direct way which adopts point-to-point pattern and is hard for operations in future complicated network environment. At the same time, there is no mature protecting measure for the reliability of network functions. This paper mainly studies on the evolution of service-based architecture in 5G Core. More specifically, it analyzes the indirect communication method based on service communication proxy and gives the advantages and implementation suggestions. Also, it analyzes the high reliability mechanism of the network function set as well as the network function service set and gives the evolution of network functions as focusing on computing and removing the functionalities of storage and switching.

Abstract：3GPP R15 does not support handoff cross SMF service area and home routing. To solve this problem, ETSUN which is the one of new features of 3GPP Release 16 is introduced. In this paper ，the application scenes, technical solutions and communication flows are introduced，and recommendating about applying ESTUN and requirement of enhancing present R15 5G network are also proposed. This will be helpful to study ETSUN technical solutions and technical requirements of network equipment.

Abstract：Device-to-Device(D2D) communication is a technology used to directly exchange information between neighboring devices in a communication network. With the characteristics of effectively improving spectrum utilization, reducing network load, and reducing communication delay, D2D technology has become a key technology to solve the current high-speed traffic growth and mass device access. Among them, resource allocation is one of the key issues in D2D communication，which is being extensively studied and discussed. This article first introduces the D2D communication technology, secondly focuses on the research status of the resource allocation algorithm in D2D communication, and finally summarizes the major and difficult problems in the research and proposes future research directions.

Abstract：In the field of speech enhancement, deep neural network can improve the enhancement ability of the model by training and modeling a large number of data with different noises in the supervised learning way. However, the acquisition cost of different types of noise is large and the noise types are difficult to be comprehensive, which affects the generalization ability of the model. Aiming at this problem, this paper proposes a noise data augmentation method based on generative adversarial network(GAN), which learns from the real noise data and synthesizes virtual noises according to the data features, so as to expand the number and type of the noise data in the training set. Experimental results show that the method of noise synthesis adopted in this article can effectively expand the source of noise in the training set, enhance the generalization ability of the model, and effectively improve the signal-to-noise ratio and intelligibility of speech signal after denoising.

Abstract：Dermatosis is a common and multiple disease in medicine, so skin detection technology has attracted more and more attention. Convolutional neural network is a common skin detection method, and its model structure will lose a lot of information. CapsNet is a new kind of neural network after convolutional neural network. The vectorization of CapsNet can better express the spatial relevance, with each capsule serving its own mission independently. This paper analyzed the basic structure and main algorithm of CapsNet, the network model was improved to avoid over fitting, and tried to identify the pre-processed skin image based on improved CapsNet, and compared it with the model of traditional convolutional neural network. Experimental results show that improved CapsNet can be used to identify pigmented skin diseases with good effect, and the accuracy is about 8～10 percent higher than the traditional method.

Abstract：In view of the lack of electricity for small fishing vessels at sea, it is difficult to support large-scale desalination equipment, an environment-friendly portable seawater desalination system is designed in this paper. The system uses smart phone as the control terminal, STM32 as the main controller, and solar energy and wind energy as the power drive. It can realize intelligent control of the equipment, wireless detection of system electricity, and GPS positioning to prevent fishing boats out of the exclusive economic zone, which can overcome the long-term drinking distilled pure water caused by the loss of micronutrient. It is proved that the system can effectively reduce the fresh water quantity of the fishermen, increase the working time, improve the endurance and self-sustaining ability of the ship, and realize the maximum operating benefit.

Abstract：With the continuous development of smart grid construction, the field of smart electricity is also developing. In this paper, a power gateway based on Linux operating system is designed according to the demand of power distribution terminal. AM335x is used as the processor, and the embedded programming is used to realize the related function of the gateway. Modbus protocol is converted into MQTT Protocol, and then the data is transferred to the cloud platform through 4G module. After testing, the power gateway runs stably and efficiently, realizes the data exchange and remote control between the traditional wired network and the wireless network, and meets the business demand of the power distribution terminal. At the same time, it provides a convenient way for the data source of the later power data analysis.

Abstract：A hexagonal fractal broadband microstrip antenna for L-band, S-band and C-band is proposed. The second-order hexagonal Sierpinski fractal structure is used as the radiation patch, and the microstrip feeding technology is used for feeding. Through simulation analysis and model optimization, the final size of the antenna is 36 mm×28 mm×1.6 mm, the relative bandwidth of -10 dB impedance is 150.3%(1.10~7.76 GHz), and the maximum peak gain is 7.80 dB at 1.10 GHz. The antenna has the advantages of simple structure, small size, large bandwidth and good gain, which can be used in various broadband communication systems.

Abstract：Reducing the energy consumption of wireless sensor nodes is the focus of intelligent algorithm research. This paper studies the power control algorithm and finds that the existing algorithm ignores the problem of multi-hop relay area, which increases the energy consumption of nodes. Therefore, this paper proposes a low-power intelligent topology control algorithm. The algorithm collects the feedback information of each node′s power consumption, forms the topology of the largest neighboring node, traverses all neighboring nodes, and selects the path with the least energy consumption. The algorithm can eliminate unreasonable multi-hop, reduce the maximum transmission power of each node, and maintain the connectivity of the whole network. In theory, the algorithm has certain practical application value.

Abstract：Because of the suddenness, crowd-gathering and destructiveness of bursty events, this paper proposes an bursty event detection method combining user influence and bursty-words for the bursty events published in weibo to avoid a series of social problems caused by bursty events. In order to extract a large number of key burst-words, we need to first calculate the bursty value of words, using two indicators: word influence and word state, taking words larger than a certain threshold as burst words; adopting cohesive hierarchical clustering method, hot topics are clustered by the co-occurrence matrix of burst word sets. After that, the results were put into the trained classifier to classify hot topics, and finally the bursty events and their types were obtained. The real microblog data were used to conduct bursty events on them. The experimental results before and after the use of the classifier were compared. This method can effectively filter common hot topics and improve the accuracy of emergency detection.

Abstract：In order to improve the shift quality and overall energy efficiency of pure electric vehicles, a multi-gear electric vehicle powertrain system with a Harpoon-shift synchronizer as an alternative to the traditional cone clutch synchronizer is presented. An original dynamic model of the Harpoon-shift mechanism is established to investigate the transient responses of driveline system during gear shifting process. A shifting control algorithm based on a special step function is put forward to improve the driving comfort. The experiments were conducted to validate the effectiveness of the proposed mathematic model and control strategy. The results indicate that the jerk reduces considerably during engagement using the optimized torque springs. Besides, it shows that the significant advantages of the proposed Harpoon-shift synchronizer compared to traditional synchronizers.

Abstract：Due to low matching performance, the original AC automaton cannot meet the application requirements of real-time large-scale feature string matching under the current big data environment. To solve this problem, a accelerated multi-mode string matching algorithm based on multi-threading is proposed, which is called PARA-AC. The algorithm cuts the string to be matched into several character substrings and a number of boundary character sets. Then these character substrings and boundary character sets to be input to the pool of threads for matching. The experimental results show that the performance of the PARA-AC algorithm is 13.91 times better than that of the original AC matching algorithm.

Abstract：Aiming at the nonlinear and non-stationary characteristics of power load data, a short-term power load forecasting model based on EMD-DA-LSSVM is proposed to improve the accuracy of short-term power load forecasting. A short-term power load prediction model EMD-DA-LSSVM is established. Firstly, EMD is used to decompose short-term power load data into uncoupled IMF components. Secondly, the EMD-DA-LSSVM short-term power load prediction model with optimal parameters is established for each IMF component, and the predicted values are obtained. Through the algorithm verification analysis, compared with LSSVM, DA-LSSVM and EMD-LSSVM, the EMD-DA-LSSVM model has higher prediction accuracy, and the short-term power load prediction accuracy is as high as 2.203 %.

Abstract：Aiming at the problem that FPGA chip power-on configuration data is easily stolen, an encryption algorithm based on CHIP ID is proposed. CHIP ID is the unique ID that comes with Altera′s Cyclone V series FPGAs.Each CHIP ID can be read by calling the IP core, this ID can be added to the personalized encryption algorithm according to the needs of developers and combined with the specified FPGA to generate configuration bitstream files. The main program runs a custom encryption algorithm to calculate an encrypted value, compares the encrypted value with the pre-stored matching value, and judges whether the program is running normally.The results show that the method using CHIP ID hardware encryption has the advantages of high-stability, high-efficiency, high-reliability, and less resource occupation.

Abstract：The noise and attenuation that affect the signal integrity are analyzed and verified. The hardware physical layer adopts pre-emphasis and equalization processing technology. The impedance matching optimization and double electrical isolation are designed to improve the signal transmission quality. At the software link layer, a two-level ping-pong buffer is designed to optimize transmission efficiency. The feedback retransmission mechanism based on cyclic redundancy check is improved to ensure that the system realizes the function of data error detection and retransmission, and can adapt to more abnormal link conditions.It has been verified that when the optimized transmission length is 100 m, the system can achieve a high reliable transmission of 180 Mb/s, which meets the technical requirements of engineering applications.

Abstract：The traditional pulse width control technology makes the switching tube in the power converter work in a hard switching state, and generates power loss that leads to efficiency decrease. Choosing the appropriate soft switching technology can effectively reduce the switching loss. This article designs a power supply product for a missile XX-11，where the front stage uses PFC circuit to achieve power factor correction, and adopts LLC resonance technology to realize the soft switching work of power tube. The switching loss is reduced, and the working efficiency of the converter is improved. The article introduces the working principle of LLC resonant circuit, uses FHA method and analyzes the influence of resonance parameters on converter gain and output efficiency, and adopts magnetic integration method to improve power density. Based on the above analysis and design, a 630W product was produced, and its electrical performance was tested and verified.

Abstract：A piezoelectric capacitive sensor can output charges directly proportional to the physical quantity to be measured in work. Due to excellent linearity and high sensitivity, it has been widely used in many fields. However, since the quantity of charges generated by such a sensor in work is relatively weak, it is necessary to amplify the charge signal for subsequent processing properly. A preamplifier circuit is designed by analyzing the equivalent circuit model of the piezoelectric capacitive sensor combined with circuit theory and Multisim simulation. As the circuit is mainly designed for amplifying signals with small amplitudes, the output signal will be distorted once it is used for an input signal with large amplitude. But in practical engineering applications, small and large input signals often appear at different conditions. To realize distortionless amplification for both small and large input signals, the design of the former preamplifier circuit is improved. Then Multisim simulation and experimental circuit testing are also carried out successively. The simulating and experimental results both show that when the input signal frequency is 10 kHz, the input signal with the amplitude up to 600 mV can be distortionless amplified by this improved preamplifier circuit. There is also no distortion when amplifying small signals. The amplification ratio is almost the same for small and large signals. These results prove that the preamplifier circuit design can realize distortionless amplification for an input signal with a high dynamic range.