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KOGPSR:A 3D GPSR algorithm using adaptive Kalman prediction for FANETs with omnidirectional antenna

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Journal of Information and Intelligence 2024年第3期2卷 191-208页

作者： Zhongjie Wang Yuhan Ruan yongzhao li Tao li Rui Zhang Jian liang School of Telecommunications Engineering Xidian UniversityXi'an 710071China

Nowadays,flying ad hoc network(FANET)has captured great attention for its huge potential in military and civilian ***,the high-speed movement of unmanned aerial vehi-cles(UAVs)in three-dimensional(3D)space leads to fast topology change in FANET and brings new challenges to traditional routing *** improve the performance of packet trans-mission in the 3D high dynamic FANETs,we propose a 3D greedy perimeter stateless routing(GPSR)algorithm using adaptive Kalman prediction for FANETs with omnidirectional antenna(KOGPSR).Especially,in data forwarding part of the KOGPSR,we propose a new link metric for greedy forwarding based on a torus-shaped radiation pattern of the omnidirectional antenna of UAVs,and a restricted flooding strategy is introduced to solve the 3D void node problem in geographic *** addition,in order to enhance the accuracy of the location information of high dynamic UAVs,we design an adaptive Kalman algorithm to track and predict the motion of ***,a FANET simulation platform based on OPNET is built to depict the performance of the KOGPSR *** simulation results show that the proposed KOGPSR algorithm is more suitable for the actual 3D high dynamic FANET.

关键词： FANET Three-dimensional space High dynamic Adaptive Kalman prediction Routing algorithm

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基于归一化循环前缀相关谱的无人机识别技术

西安电子科技大学学报 2024年第2期51卷 68-75页

作者：张涵硕李涛李勇朝温志津西安电子科技大学通信工程学院陕西西安710071 电磁空间认知与智能控制技术实验室北京100191

基于射频的无人机识别技术具有探测距离长、环境依赖性低的优点,已成为无人机监控系统不可或缺的技术手段。如何在低信噪比条件下有效识别无人机是当前热点问题。为保证良好的图传质量,无人机通常采用带有循环前缀结构的正交频分复用(OF... 详细信息

基于射频的无人机识别技术具有探测距离长、环境依赖性低的优点,已成为无人机监控系统不可或缺的技术手段。如何在低信噪比条件下有效识别无人机是当前热点问题。为保证良好的图传质量,无人机通常采用带有循环前缀结构的正交频分复用(OFDM)调制作为图传链路的调制方式。据此特性,首先提出一种基于归一化循环前缀相关谱和卷积神经网络的无人机识别算法。依据对无人机信号的OFDM符号周期和循环前缀长度的分析结果,计算信号归一化循环前缀相关谱。当归一化循环前缀相关谱的计算参数与无人机信号的调制参数匹配时,谱线中会出现若干相关峰,峰的位置分布反映了无人机信号帧结构、突发规则等协议特征。然后,利用卷积神经网络对归一化循环前缀相关谱进行特征分析和提取,从而识别无人机。最后,利用通用软件无线电平台USRP X310对5款无人机的射频信号进行采集,构建实验数据集。实验结果表明,该算法优于基于频谱和基于时频谱的算法,且在低信噪比下仍然有效。

关键词：无人机射频信号 OFDM 归一化循环前缀相关谱

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Support vector classifier based on principal component analysis

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Journal of Systems Engineering and Electronics 2008年第1期19卷 184-190页

作者： Zheng Chunhong Jiao licheng li yongzhao School of Electronic Engineering Xidian Univ. Xi'an 710071 P. R. China

Support vector classifier （SVC） has the superior advantages for small sample learning problems with high dimensions, with especially better generalization ability. However there is some redundancy among the high dimensions of the original samples and the main features of the samples may be picked up first to improve the performance of SVC. A principal component analysis （PCA） is employed to reduce the feature dimensions of the original samples and the pre-selected main features efficiently, and an SVC is constructed in the selected feature space to improve the learning speed and identification rate of SVC. Furthermore, a heuristic genetic algorithm-based automatic model selection is proposed to determine the hyperparameters of SVC to evaluate the performance of the learning machines. Experiments performed on the Heart and Adult benchmark data sets demonstrate that the proposed PCA-based SVC not only reduces the test time drastically, but also improves the identify rates effectively.

关键词： support vector classifier principal component analysis feature selection genetic algorithms

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Recursive Feature Elimination Based Feature Selection in Modulation Classification for MIMO Systems

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Chinese Journal of Electronics 2023年第4期32卷 785-792页

作者： ZHOU Shuai li Tao li yongzhao School of Telecommunications Engineering Xidian University

The feature-based(FB) algorithms are widely used in modulation classification due to their low complexity. As a prerequisite step of FB, feature selection can reduce the computational complexity without significant performance loss. In this paper, according to the linear separability of cumulant features, the hyperplane of the support vector machine is used to classify modulation types, and the contribution of different features is ranked through the weight vector. Then, cumulant features are selected using recursive feature elimination(RFE) to identify the modulation type employed at the transmitter. We compare the performance of the proposed algorithm with existing feature selection algorithms and analyze the complexity of all the mentioned algorithms. Simulation results verify that the proposed RFE algorithm can optimize the selection of the features to realize modulation recognition and improve identification efficiency.

关键词： Transmitters Simulation Modulation Support vector machine classification Feature extraction Classification algorithms Computational complexity

Improved BLAST for wireless communications

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Journal of Systems Engineering and Electronics 2006年第1期17卷 48-53页

作者： li yongzhao liao Guisheng Wang Feng National Key Lab for Radar Signal Processing Xidian Univ. Xi'an 710071 P. R. China Shanghai Research Inst. of Huawei Technologies Co. LTD Shanghai 200050 P. R. China

Bell layered space-time architecture （BLAST） is a multi-antenna communication structure with high spectrum efficiency, and it has found wide applications in LANs and WLANs. However, its performance is much poorer than those of other space-time coding approaches. In order to improve its performance, an improved BLAST based on RAKE receiving is investigated. The new system introduces orthogonal spreading sequences （OSS） into the transmitter while retains the basic structure of BLAST. The proposed receiver suppresses interferences from other antennas by the orthogonality contained in the received signals, and extracts information from each receiving antenna by using RAKE receiving principle to construct efficient statistic decision. Simulation results show that the improved system performs well over both frequency-fiat and frequency-selective fading channels.

关键词： bell layered space-time architecture orthogonal spreading sequences RAKE receiving

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A high power efficiency method using orthogonal signal decomposition in high PAPR system

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Science China(Information Sciences) 2013年第4期56卷 173-179页

作者： REN ZhiYuan li yongzhao ZHANG Hailin HAN Kun State Key Laboratory of Integrated Services Network Xidian University Xi'an Communication Institute

To solve the low-power-efficiency problem for high peak to average power ratio systems,such as OFDM,an orthogonal inhomogeneous signal decomposition approach is proposed in this *** novel method decomposes the signal into branch signals orthogonally,which can adapt to the change of saturate power of each branch power ***,the novel method has the advantages of both high power efficiency of power amplifier and low PAPR of branch ***,this is more suitable for practical *** simulation results indicate that the proposed method can increase the power efficiency remarkably without reducing the BER performance in the receiver.

关键词： green radio power amplifier orthogonal inhomogeneous signal decomposed power efficiency energy conservation

Performance evaluation for underlay cognitive satellite-terrestrial cooperative networks

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Science China(Information Sciences) 2018年第10期61卷 213-223页

作者： Yuhan RUAN yongzhao li Cheng-Xiang WANG Rui ZHANG Hailin ZHANG State Key Laboratory of Integrated Service Network Xidian University School of Engineering and Physical Sciences Heriot-Watt University

With the continuously increasing demand for broadband applications and services, underlay cognitive satellite-terrestrial networks, enabling to accommodate better wireless services within the scarce spectrum, have attracted tremendous attentions recently. In this network, satellite communications are allowed to operate in the frequency bands allocated to terrestrial networks under the interference constraints imposed by terrestrial network, which may lead to a performance degradation of the satellite network. To guarantee the performance of the primary terrestrial network as well as the secondary satellite network, we introduce the cooperation into cognitive satellite-terrestrial networks and investigate the performance of the new framework, i.e., cognitive satellite-terrestrial cooperative network(CSTCN). Specifically, by restricting the transmit power of satellite communications with interference power constraints imposed by terrestrial communications, we firstly obtain the received signal-to-interference-plus-noise ratio(SINR) of the considered network. Moreover, by employing the moment generating function(MGF) approach, closed-form expressions for symbol error rate(SER) and outage probability(OP) of the considered cognitive network are *** analytical results obtained in this paper can provide theoretical support for optimizing the performance of satellite-terrestrial networks.

关键词： cognitive satellite-terrestrial cooperative network interference constraints moment generating function symbol error rate outage probability

威远311.1 mm井眼优快钻井技术的难点与对策

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化工管理 2024年第4期 90-92页

作者：常杨李永钊朱俊武李鹏娜中国石油集团长城钻探工程有限公司工程技术研究院辽宁盘锦124000

四川页岩气311.1 mm井眼压力体系复杂,层位多变化不定,部分地层可钻性差,钻进过程中存在滑动托压严重、机械钻速慢、井漏、气侵、卡钻事故频发等问题,严重影响了整体勘探开发。通过该井段的大数据分析,基于地质特点和易漏、卡钻等工程难... 详细信息

四川页岩气311.1 mm井眼压力体系复杂,层位多变化不定,部分地层可钻性差,钻进过程中存在滑动托压严重、机械钻速慢、井漏、气侵、卡钻事故频发等问题,严重影响了整体勘探开发。通过该井段的大数据分析,基于地质特点和易漏、卡钻等工程难点,从井下设备、井眼轨迹、钻井液性能调整和钻井参数设定等方面,提高机械钻速。但目前地面参数只是在客观陈述机械钻速变慢,钻头处实际获取的参数并未可知。利用井下钻压、转速和扭矩参数,结合机械钻速和水力参数表现整合成一个综合参数,规避井下作业风险的同时,真实评定井下工作状态,建立多元钻井参数实时优化系统,形成智能钻井服务能力,从而实现优快钻井技术。

关键词：钻压转速钻井技术

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Energy efficient power allocation for underlaying mobile D2D communications with peak/average interference constraints

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Science China(Information Sciences) 2018年第8期61卷 225-227页

作者： Rui ZHANG yongzhao li Cheng-Xiang WANG Yuhan RUAN Hailin ZHANG State Key Laboratory of Integrated Service Network Xidian University School of Engineering and Physical Sciences Heriot-Watt University

Dear editor,Recently,Device-to-Device(D2D)communication is conceived as a candidate paradigm to provide ultra-reliable and low-latency services or high data rate required applications for future intelligent transporta... 详细信息

关键词： SE EE Energy efficient power allocation for underlaying mobile D2D communications with peak/average interference constraints