运营商流量经营战略及BSS域的作为空间

通过运用“用户-产品-资源”三角关系模型分析移动互联网时代运营商流量经营的三个困境,得出流量经营战略的关键是供求平衡、量质并重。进一步解读三大运营商的流量经营战略,得出业务支撑域在流量经营战略中的五个作为空间,共同构成了智能管道的“智”在BSS域的映射。     

利用盲源分离算法实现DOA估计

提出一种基于快速盲源分离算法实现波达方向（DOA）估计的方法。构造了具有对角化结构的相关矩阵组,引入解盲源分离问题的联合对角化代价函数,采用一种快速的复数域乘性迭代算法求解代价函数,得到混迭矩阵逆的估计,进而实现DOA估计。与同类算法相比,该算法具有更广的适用性和更精确的DOA估计性能。仿真实验结果验证了算法的快速收敛性和优越的估计性能。     

基于子空间和小波降噪的盲信号干扰抑制算法

卫星通信信号十分微弱,信噪比的改善以及抗干扰能力的增强对于信号的正确接收具有至关重要的作用。提出了一种星上干扰抑制方案和一种基于子空间和小波降噪的盲分离干扰抑制算法,对提出的算法在单音、多音、窄带噪声以及宽带噪声干扰下进行了误码性能仿真。结果表明,该算法克服了传统基于前置小波降噪的盲分离算法在干信比大于30dB时性能恶化的问题,提高了抗高斯白噪声性能。     

An Improved Multiplicative Updating Algorithm for Nonnegative Independent Component Analysis

This paper addresses nonnegative independent component analysis (NICA), with the aim to realize the blind separation of nonnegative well‐grounded independent source signals, which arises in many practical applications but is hardly ever explored. Recently, Bertrand and Moonen presented a multiplicative NICA (M‐NICA) algorithm using multiplicative update and subspace projection. Based on the principle of the mutual correlation minimization, we propose another novel cost function to evaluate the diagonalization level of the correlation matrix, and apply the multiplicative exponentiated gradient (EG) descent update to it to maintain nonnegativity. An efficient approach referred to as the EG‐NICA algorithm is derived and its validity is confirmed by numerous simulations conducted on different types of source signals. Results show that the separation performance of the proposed EG‐NICA algorithm is superior to that of the previous M‐NICA algorithm, with a better unmixing accuracy. In addition, its convergence speed is adjustable by an appropriate user‐defined learning rate.     

Selecting transition process for WLAN security

In wireless local area network (WLAN), a station (STA) accesses the Internet through an access point (AP). When switching from one AP to another, the STA executes the transition process, which may incur long delay and result in force‐termination for real‐time applications. The IEEE 802.11r proposes the fast basic service set (BSS) transition to speed up the transiti on process for a STA moving within the same mobility domain (MD). This scheme requires unique MD assignment so that the STA knows whether it should conduct fast BSS transition process (for intra‐MD scenario) or the expensive initial MD association process (for inter‐MD scenario). However, how to guarantee unique MD identifier (MDID) assignment is not mentioned in the specification. This paper proposes a mechanism for IEEE 802.11r fast transition without using MDID, and therefore eliminates the cost for MDID management. Copyright © 2007 John Wiley & Sons, Ltd.     

漫谈业务支撑系统的建设与发展

对现阶段业务支撑系统(BSS)建设面临的几个发展重点进行了阐述,提出了BSS建设发展中的3个关键管控环节,对BSS建设中的若干问题进行了讨论,并提出了建议。     

基于负熵的多目标射频信号分离研究

为了改变在复杂条件下的多目标射频识别技术依靠防冲突算法的现状,引入独立分量分析技术,在射频阅读器信号采集后端,增加混合射频信号分离过程,采用负熵度量非高斯性准则,将空间中混合的射频信号逐一分离,实现多目标射频信号分离。通过实验例证该方法的可行性,取得了较好的分离效果,为多频段、大范围的多目标射频信号识别技术发展提供了思路。     

山西联通IT支撑系统的设计与实现

文章以山西联通IT支撑系统的设计和实施为例,对IT支撑系统的技术架构、功能架构以及进行了阐述,该系统计能够有效地支撑山西联通IT系统的自动化采集、系统故障监控,实现了快速定位问题、及时告警、缩短故障处理时长。     

固网与移动业务支撑系统融合方案研究

在充分研究运营商BSS系统现状与未来业务需求的基础上,提出了固网、移动BSS系统融合的思路与步骤,从系统、功能、数据、流程等方面对固网、移动BSS系统融合方案进行了详细阐述,并对使用的关键技术进行了分析。     

自动化测试在业务支撑系统接口测试中的应用设计

为了提升测试效率,本文将自动化测试技术应用到业务支撑系统接口的测试。文中通过对接口测试的共性特点和自动化测试技术特点的分析,设计了基于用例和脚本模板化的接口自动化测试平台,给出了平台的功能框架、平台开展测试的核心流程、以及平台的3层实现架构。在对业务支撑系统的接口测试内容进行归类后,本文还给出了一些测试用例和测试脚本的模板,以对接口自动化测试平台设计作进一步的说明。