共查询到20条相似文献,搜索用时 760 毫秒
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高铁覆盖传播模型的探讨 总被引:4,自引:2,他引:2
介绍了当前广泛采用的宏小区覆盖模型,即Okumura—Hata模型和COST-231-Hata模型。通过模拟测试数据的分析,总结出2种可供高速铁路覆盖设计参考的覆盖传播模型,即自由空间附加损耗模型和衰减因子传播模型。 相似文献
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准确的传播模型是5G移动通信网小区合理规划的基础。文章将深度学习方法与无线传播模型相结合,利用深度学习算法获取影响路径损耗的场景化因素特征,建立基于深度学习的无线传播模型。外场实际道路测试和用户测量报告评估验证表明,基于深度学习的场景化5G传播模型的覆盖预测准确,更加匹配真实的网络场景,保证5G无线网络规划建设的质量。 相似文献
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为定量评判已校传播模型的准确性,文章提出了一种基于验证站点测试的模型验证方法,并给出了定量评判指标,解决了工程中模型验证的难题;最后通过工程实例,证明了该方法的有效性。 相似文献
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陆地移动通信中几种常用的传播损耗模型 总被引:1,自引:0,他引:1
这篇文章概括地讨论了陆地移动几种常用的传播损耗模型,提纲了各种模型的使用及其相关参数。涉及内容包括宏小区、微小区和微微小区等几个方面。 相似文献
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分析了一种新型微小区的电波传播,预测城市小区环境下的传播损耗。该方法建立在电波传播和几何光学理论及费塞尔理论的基础上,分析考虑了不同情况下电波的空间传播与屋顶衍射,计算出路径的传播损耗。 相似文献
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射线跟踪方法是研究室外微蜂窝小区电波传播的有效方法。基于入射及反弹射线法/ 镜像法对室外微小区环境中3. 5GHz 电波传播的路径损耗进行了仿真和分析,仿真结果与文献所给的结果一致性良好,验证了该
方法的正确性。提出了一种新型的射线管判收方法,可有效判断到达接收机的所有射线管。分析了仿真中得到的接收功率、均方根时延扩展、波达方向等传播参数,并比较了视距传播(LOS)和非视距传播(NLOS)的传播特性,这些分析结果可为3. 5GHz 频段无线通信系统的覆盖提供相应的理论依据。 相似文献
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WCDMA无线传播模型校正 总被引:3,自引:0,他引:3
传播模型的准确对小区的合理规划是十分重要的。利用CW测试获得的数据与数字地图对传播模型进行校正。介绍了单变量校正法和多变量校正法,最后给出了一个传播模型校正实例。 相似文献
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Joint video/depth rate allocation for 3D video coding based on view synthesis distortion model 总被引:1,自引:0,他引:1
Yanwei Liu Qingming Huang Siwei Ma Debin Zhao Wen Gao 《Signal Processing: Image Communication》2009,24(8):666-681
Joint video/depth rate allocation is an important optimization problem in 3D video coding. To address this problem, this paper proposes a distortion model to evaluate the synthesized view without access to the captured original view. The proposed distortion model is an additive model that accounts for the video-coding-induced distortion and the depth-quantization-induced distortion, as well as the inherent geometry distortion. Depth-quantization-induced distortion not only considers the warping error distortion, which is described by a piecewise linear model with the video power spectral property, but also takes into account the warping error correlation distortion between two sources reference views. Geometry distortion is approximated from that of the adjacent view synthesis. Based on the proposed distortion model, a joint rate allocation method is proposed to seek the optimal trade-off between video bit-rate and depth bit-rate for maximizing the view synthesis quality. Experimental results show that the proposed distortion model is capable of approximately estimating the actual distortion for the synthesized view, and that the proposed rate allocation method can almost achieve the identical rate allocation performance as the full-search method at less computational cost. Moreover, the proposed rate allocation method consumes less computational cost than the hierarchical-search method at high bit-rates while providing almost the equivalent rate allocation performance. 相似文献
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针对无线电波远距离空—地传播,为了得到其在球面反射两径模型下的多径衰落特性,介绍了自由空间路径损耗和平面反射两径传播的数据模型。分析了球面反射两径传播的几何模型,并提出了用二分法确定几何反射点的位置,进而得到等效天线高度和扩散因子后用平面反射模型计算球面反射接收信号功率的方法。给出了基于矩阵实验室(MATLAB)编程的方法和仿真结果分析。 相似文献
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Video steganography forms a covert communication channel by data embedding in cover elements. To consider inter-frame mutual embedding impacts, this paper proposes a payload allocation strategy in video steganography based on motion vector modification distortion analysis. Firstly, the motion vector modification distortion caused by data embedding is analyzed. Then, a rate–distortion model reflecting the residue deviation propagation in successive inter-coded frames is derived. According to this model, the residue deviation propagation weight of each inter-coded frame can be computed. Finally, an inter-frame payload allocation strategy is designed in order to restrain the residue deviation propagation. Experimental results demonstrate that the proposed payload allocation strategy can enhance existing motion vector-based video steganographic methods in terms of undetectability and video coding performance. Besides, the lower computational complexity can be achieved. 相似文献
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李延峰 《电信工程技术与标准化》2022,(2)
2020年5月20日,中国移动与中国广电签订共建共享合作框架协议,双方共建共享700MHz无线网,助力5G生态环境发展,推动5G服务大众及行业。前期700M频段为广电专用网络,国内通信业对该频段传播特性研究较少。网络规划需要精准的传播模型,传播模型对于站间距的合理设计、网络性能的准确仿真有决定性作用,必须对传播模型开展校正及数据分析,以支撑700M无线网规划工作。该论文基于SPM模型,通过对700M传播模型校正过程的分析和统计处理,最终得出700M传播模型及相关指标参数,为700M系统落地提供参考。 相似文献
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Based on the standard SPM,an improved sea surface propagation model was proposed.At the same time,a propagation model correction algorithm based on WLS algorithm was proposed.Using the CW test data of Qiongzhou Strait,the parameters of the improved SPM were corrected.Based on the corrected propagation model,the current base station of Qiongzhou Strait coast was used to carry out link level simulation and coverage simulation for NB-IoT.The experimental results show that the proposed method can effectively achieve the coverage of NB-IoT in Qiongzhou Strait and contribute to the scientific research of Internet of things. 相似文献
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受限于CW测试工作量和目前各主要频段都已经在使用的无线传播环境条件,无法对每个城市、每个场景进行无线传播模型校正.本文提出基于地物类型矢量距离的TD-LTE无线传播模型映射方法,即根据地物类型最小矢量距离的映射关系,为无CW测试校正的城市或场景选取合适的传播模型.通过对二维不加权、二维加权和多维加权进行ANPOP仿真对比分析,证明多维加权矢量距离映射方法可靠性最高,对精细化网络规划和工程建设具有实际指导意义. 相似文献
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传播模型校正是网络规划中关键的环节,本文首先介绍了传播模型校正的原理和方法,并对传播模型校正中CW测试数据的预处理进行了分析,进一步以实际网规工具中应用的实例分析了传播模型校正中的关键点,对实际的网络规划提出了指导。 相似文献