TD—SCDMA位置区划分方法分析

位置区的划分是TD—SCDMA网络规划很重要的一环。文章对TD—SCDMA位置区寻呼容量进行了分析,并探索如何利用GSM小区切换统计数据来开展TD—SCDMA位置区边界划分,最后总结TTD—SCDMA位置区划分的一般方法。     

应用大数据分析自动识别边界漫游小区

通过对边界漫游特点和现状的分析,阐述边界基站本身具有的三个特点,提出减少边界漫游计费差错的关键是及时识别边界漫游小区,并尝试基于全量的用户通信记录数据建立大数据分析模型,自动识别出疑似边界小区,为边界漫游小区信息的及时、准确更新提供有力的技术支撑。     

吉首CDMA网络边界小区寻呼问题的研究

湖南省多为丘陵地形,特别是湘西一带,地形地貌复杂。在这些地区的CDMA网络中,交换机交界地区信号的交叉覆盖严重,造成手机频繁登记,寻呼成功率不高、交换信令负荷加重。面对边界小区的寻呼问题,如果开启延迟登记功能解决边界小区寻呼问题,可能会增加寻呼失败率,应该在此基础上开启BCP（边界小区寻呼）功能解决边界小区寻呼问题,并通过湘西吉首运用BCP功能解决边界小区寻呼问题的应用案例进行验证。     

LTE系统中的功率控制技术

3G系统采用CDMA多址方式,小区内/小区间的用户使用相同的频率资源,同频干扰较大,而LTE系统采用OFDMA多址方式,小区内的不同用户占用不同的频率资源,小区间一般占用相同的频率资源,小区内用户间同频干扰相对减弱,因此,在主要用于解决干扰问题的功率控制技术方面, LTE系统比3G系统有较大简化。本文重点介绍LTE系统的功率控制技术,在介绍之前,首先分析了LTE系统的干扰情况,随后对现有系统中的通用功率控制技术进行探讨,从而引出LTE系统的功率控制方案。     

HAPS通信覆盖及链路特性分析

由高空平台(HAP)构成的信息系统将是新一代的无线通信系统,它融合了陆地和卫星通信系统的优势,又不同程度地避免了两者的缺点,在通信领域的应用得到了广泛认同,是现有通信方式的有效补充。通过重点研究高空平台站(HAPS)通信的覆盖特性、多波束小区划分方案、链路特性及功率控制等关键问题,提出了一种适应HAPS通信多波束小区划分方案,并且通过计算与仿真分析比较,说明提出方案更适应HAPS通信场景,为HAPS通信的工程实现提供了参考。     

关于移动通信系统中蜂窝的几个概念

目前的移动通信系统一般采用小区制,即将整个网络服务区域划分为若干小区,每个小区分别设有一个（或多个）基站,用以负责本小区移动通信的联络和控制等功能。因此移动网络的覆盖区可以看成是由若干正六边形的无线小区相互邻接而构成的面状服务区。由于这种服务区的形状很像蜂窝,我们便将这种系统称之为蜂窝式移动通信系统,与之相对应的网络称之为蜂窝式网络。宏蜂窝小区传统的蜂窝式网络由宏蜂窝小区（ｍａｃｒｏｃｅｌｌ）构成,每小区的覆盖半径大多为１ｋｍ～２５ｋｍ。由于覆盖半径较大,所以基站的发射功率较强,一般在１０Ｗ以…     

大尺度信干比共享下的基站协作干扰协调

在基于正交频分多址接入(OFDMA)技术的蜂窝移动小区中,小区间的干扰是影响系统性能的主要因素。多点协调(CoMP)技术被视为能够协调小区间干扰的主要手段。在下行多点协作传输系统中,小区基站采用三向天线来对小区划分扇区,从而消除了相邻小区边缘处的干扰。各扇区分别计算扇区内用户的大尺度信干比(SIR),小区之间通过共享大尺度信干比信息,对各自服务的用户按照一定的规则进行匹配,对小区中心用户的SIR和边缘用户的SIR进行了折中,从而有效解决小区边缘用户由于小区间干扰带来的低信干噪比(SINR)问题。仿真结果表明,本文提出的用户匹配算法以较小的反馈开销,较大的提高了小区边缘用户的信干噪比和系统吞吐量。      

关于移动通信系统中蜂窝的几个概念

目前的移动通信系统一般采用小区制,即将整个网络服务区域划分为若干小区,每个小区分别设有一个（或多个）基站,用以负责本小区移动通信的联络和控制等功能。因此,移动网络的覆盖区可以看成是由若干正六边形的无线小区相互邻接而构成的面状服务区。由于这种服务区的形状很像蜂窝,我们便将这种系统称之为蜂窝式移动通信系统,与之相对应的网络称之为蜂窝式网络。 传统的蜂窝式网络由宏蜂窝小区构成,每小区的覆盖半径大多为1～25km。由于覆盖半径较大,所以基站的发射功率较强,一般在10W以上,天线也做得较高。图1是由宏蜂窝组成的移…     

小区级策略管控研究

对高性价比小区级部署策略控制架构进行研究,通过划分小区类型进行筛选,针对特定类型小区通过深入分析、量化评估等方式进行分析。     

一种基于改进网格聚类的雷达信号预分选算法

基于网格的聚类算法是雷达信号预分选领域的一种常用方法。针对现有网格聚类算法需要人为确定网格划分、边界处理精度低的问题,提出一种改进的网格聚类算法,该算法对输入雷达信号脉冲顺序不敏感,根据网格数据压缩率自适应确定网格划分和密度阈值。仿真实验验证了算法的有效性和抗噪声能力。     

LINDASearch: a faceted search system for linked open datasets

Wireless Networks - The importance of Linked Data lies on the fact that its practices and principles have been adopted by an increasing number of data providers, resulting in the creation of a data...     

High-temperature superconducting films on flexible substrates for flux transformers

The growth of the high-temperature superconductors (HTSCs) on flexible films for the fabrication of nanoelectronic devices is considered. A method for the creation of the HTSC films on the nickeltungsten substrates is proposed. The deposition of the CeO₂ and YBCO epitaxial films that are grown on short substrates made of flexible nickel-tungsten ribbon manufactured using the RABiTS technology is comprehensively analyzed, and the properties of the resulting HTSC films are studied. The electrophysical properties of the HTSC films on flexible substrates are demonstrated.     

Design of line source antennas for narrow beamwidth and asymmetric low sidelobes

A design method is described for the creation of line sources that will yield antenna patterns consisting of a narrow main beam and low sidelobes, with the sidelobe levels different on the two sides of the main beam. The requisite aperture distribution is shown to be symmetrical in amplitude and asymmetrical in phase. Main beam offset and the characteristics of the associated difference pattern are discussed. The boresight error voltage curve is also displayed. Incremental gain resulting from asymmetric sidelobes is analyzed and data is given for typical cases. Experimental confirmation is, presented.     

Modeling the human knee for assistive technologies

In this paper, we use motion capture technology together with an EMG-driven musculoskeletal model of the knee joint to predict muscle behavior during human dynamic movements. We propose a muscle model based on infinitely stiff tendons and show this allows speeding up 250?times the computation of muscle force and the resulting joint moment calculation with no loss of accuracy with respect to the previously developed elastic-tendon model. We then integrate our previously developed method for the estimation of 3-D musculotendon kinematics in the proposed EMG-driven model. This new code enabled the creation of a standalone EMG-driven model that was implemented and run on an embedded system for applications in assistive technologies such as myoelectrically controlled prostheses and orthoses.     

Towards Automatic Creation of Realistic Anthropomorphic Models for Realtime 3D Telecommunication

This contribution describes the creation of highly realistic 3D models of participants for distributed 3D videoconferencing systems. These models consist of a flexible triangular mesh surrounding an interior skeleton structure, which is based on a simplified human skeleton. The vertices of the predefined mesh template are arranged in rigid rings along the bones of the skeleton. Using 3D data obtained by a stereoscopic approach the size and shape of this initial mesh is adapted to the real person. Adaptation allows to texture the model from real images leading to a natural impression. The mesh organization in rigid rings gives an efficient way for surface deformation according to the skeleton movements. The resulting model is transmitted once and subsequently animated using the simple parameter set of the interior skeleton structure.     

Integrated service creation environment for open network services

The service creation scheme is changing with the advent of open network service architecture for next-generation network. New requirements should be considered for IT domain developers to create telecom and Internet combined services more easily. This paper describes an integrated service creation environment (SCE) to reflect the trend of network evolution toward an open network environment. The SCE provides multiple service programming tools to support various users’ background, a mash-up toolkit for IT domain, a simulation-based validation tool, a run-time adaptation tool, and a personalized service provisioning environment. Several example services were implemented to verify the features of an integrated SCE. Our approach is very promising because it supports various requirements and background of service developers on the full service creation process. Furthermore, it provides a means for personalized service creation driven by end-user, which is a new trend of future network.     

一种面向网络安全实验平台的场景快照方法

针对网络安全实验平台基于远程命令创建场景快照存在快照创建不一致的问题,提出一种基于中心授时和定时快照生成的解决方法。该方法采用在实验场景中引入授时中心的方式,实现对场景时间的全局统一,并通过将远程快照创建改为定时创建的方式,实现全场景所有节点创建快照时间的一致。与远程创建快照、不采用授时中心的场景快照定时创建方式的对比显示,该方法能够大大提升场景快照的一致性,有效解决了基于远程命令创建场景快照带来的不一致问题。     

化学腐蚀对声表面波器件性能影响分析

Al膜的化学腐蚀直接影响声表面波器件的可靠性,造成器件功能性失效。该文对SAW器件Al膜的化学腐蚀的机理、过程、产生的条件、对器件性能及可靠性的影响进行了分析,并对其进行了试验验证和检测,以及在生产过程中如何加以预防和控制进行了阐述。     

Method for replica creation in data grids based on complex networks

In order to reduce makespan and storage consumption in data grids,a node selection model for replica creation is proposed.The model is based on the degree distribution of complex networks.We define two candidate replica nodes: a degree-based candidate pool and a frequency-based candidate pool,through which a degree-based candidate pool is defined m consideration of onsidering the access frequency,a candidate pool-based frequency is also defined.The data replica is copied to the node with the minimum local cost in the two pools.Further,this paper presents and proves a replica creation theorem.A dynamic multi-replicas creation algorithm(DMRC)is also provided.Simulation results show that the proposed method may simultaneously reduce makespan and data used in space storage consumption.     

A lifetime prediction method for oxide electron trap damage createdduring hot-electron stressing of n-MOS transistors

Electron trap creation under conditions of hot-electron stress (i.e., stress at V_d=V_g) is examined. It is shown that a relationship exists linking lifetime to the injected gate current and drain current, offering a lifetime prediction method for these types of traps. Comparing this type of damage to interface trap (N_it) creation, it is found that larger energies (approximately 1.5 times that for N_it) are required to generate this defect. It is shown that an extrapolation technique can be used to obtain gate currents at working circuit voltages, extending the prediction of lifetimes for oxide trap creation to low voltages