一种新的基于多业务的移动通信系统切换策略

针对目前移动通信系统大部分信道切换策略中新呼叫阻塞率高的问题,提出了一种新的呼叫延迟切换策略,该策略是让即将占用最后一个空闲信道的新呼叫短暂延迟后再占用空闲信道,切换呼叫则直接占用空闲信道,缩短了信道被全部占用的时间,增加了新呼叫和切换呼叫占用信道的机会。该策略同时考虑了数据业务之间的优先级,只有当高优先级数据队列中的数据包为空时,低优先级队列中的数据包才能够占用信道。给出了切换呼叫掉话率、新呼叫阻塞率及数据包掉包率的理论公式。与预留信道策略和可移动边界策略的对比表明,新策略既提高了新呼叫进入系统的概率,又有效降低了切换呼叫的掉话率,同时也减少了高优先级数据的掉包率。     

基于高斯粒子滤波法的CIR利率期限结构估计

为了提高CIR利率期限结构模型中的状态估计精度,建立了该问题的离散非线性滤波模型,采用高斯粒子滤波法进行状态近似最优估计.相对于文献中普遍采用的扩展卡尔曼滤波方法,高斯粒子滤波法避免了线性近似带来的误差,利用基于重要性采样得到的高斯分布来近似状态变量的后验分布,具有更强的状态估计能力.仿真实验比较了高斯粒子滤波和扩展卡...     

Resource allocation for MIMO-OFDMA downlink based cognitive radio systems with imperfect channel learning

This paper is concerned with the resource allocation for multiple input multiple output and orthogo- nal frequency division multiplexing access （MIMO-OFDMA） downlink cognitive radio systems where a cognitive radio MIMO-OFDMA system is under spectrum sharing with an existing primary radio （PR） network. We use the channel learning scheme to estimate the channel information from cognitive radio transmitter （CR-TX） to PR and then make beamforming to transmit signal. Considering the interference from CR-TX to PR caused by the imperfect channel learning, we intend to maximize CR throughput under the interference power constraint at PR and CR transmit power constraint. A nearly optimal subcarrier and power allocation algorithm with linear complexity is proposed. The proposed algorithm is global optimal when the maximum transmit power is beyond certain threshold. Simulation results show that the proposed algorithm has a good performance very close to the global optimal algorithm.     

A self-verification authentication mechanism for mobile satellite communication systems

In order to provide an opportunity to make personal communication as broad as possible, mobile satellite communication systems have recently drawn much attention. However, any communication system raises two major challenging issues: (1) how to determine whether actors are whom they claim to be; and (2) how to protect data against unauthorized disclosure. Although the secret-key cryptosystem (SKC) and the public-key cryptosystem (PKC) have been developed to provide well-defined security services to address these issues each has serous drawbacks while SKC-based authentication schemes have the common demerit that the server which maintains the secret-key table becomes an attractive target for numerous intrusions, PKC-based schemes suffer from the expensive complexity of the public-key infrastructure (PKI) and a high computation overhead. Therefore, in this paper, a self-verification authentication mechanism with lower computation and key management cost is introduced.     

基于移动通信切换特性的L2-Trigger方法

有文献提出采用二层触发器提前触发三层切换的方法以适应移动IP中的实时应用,但是现有的方法存在指示不准确、触发方法不明确等问题。为此,给出了新的二层触发器方法,并给出具体的路由更新协议DRPR,从而消除了移动节点（MN）切换时的注册时延。     

基于移动IPv6的高速铁路通信快速切换方法

针对高速铁路移动通信系统中越区频繁、切换速度快、丢包延时等问题,根据高速铁路列车运行的自身特点,将移动IPv6切换技术与高速铁路移动通信网络相结合,在快速切换方案的基础上进行改进,提出了一种基于预测的高速铁路移动通信切换方法,为高速铁路安全高效运行提供了可靠优质的移动通信服务。实验结果表明,该方法缩减了移动检测、转交地址配置和重复地址检测的时间,提高了切换效率,解决了由于快速频繁切换而导致的网络资源利用率低和切换延迟大的问题。     

Hierarchical matched filter based on FPGA for mobile systems

The paper is concerned with the design of field programmable gate array (FPGA) based hierarchical matched filter (HMF) for new generation cellular mobile radio systems. This is considered as the most important task of the receiver and should be implemented with minimum hardware. The synchronization codes considered in the work is the one used in wideband code division multiple access (W-CDMA) system as described by the third Generation Partnership Project (3GPP) specifications. The proposed system relies on the use of the hierarchical matched filter using transposed structure of finite impulse response (FIR) filter. The HMF implementation is verified to perform the required partial correlation. A simplified design for the realization of the filter tap is presented. This has the advantage of being configurable and flexible to reduce the overall hardware complexity of the system.     

基于移动代理技术的移动IP网络中链路快速建立方法

提出了一种新型移动IP漫游切换过程中链路建立方法,通过在移动主机中集成移动代理,并结合MPLS来完成链路建立时的自动信令和自主建立过程,可以改变目前移动IP网络中树状的网络体系结构,使得切换时建立新链路的信令过程大大简化,显著减小切换时延。给出了链路建立过程和性能分析,通过仿真模拟可以减少时延27%~41%。     

一种适用于移动通信的公钥加密认证方案

提出了一种基于数字签名和公钥加密的认证与密钥协商方案,该方案可以实现移动用户与移动服务提供商的互认证和密钥协商。协议在移动用户端只进行杂凑运算,计算量小,可靠性高,比较适合移动通信环境。     

A communication protocol based on IR-space division transceivers for mobile robots

In this article, we propose MAC protocols based on our infrared-space division transceiver (IR-SDT) for mobile robots. The IR-SDT has eight communication modules, so it can communicate with a maximum of eight other nodes simultaneously. The number of parallel multiple accesses will be improved by using this transceiver and its specialized protocol. In addition, we consider situations in which a packet collision occurs, and propose a protocol that resolves communication conflicts using the signal collision-detection function of IR-SDT. Finally, we consider the performance of these protocols, and discuss the influence of signal collision-detection accuracy.     

基于SVM分类机的移动通信欺诈检测系统

设计并实现了一种基于SVM分类机(支持向量机)的入侵检测系统,它搜集移动通信客户的产品信息、呼叫行为信息(CDR)、背景资料、交欠费信息等特征,采用主成份分析(PCA)的属性归约技术对数据进行预处理,然后使用SVM分类机对测试数据进行分类,从而识别出新用户的欺诈类型。在此基础上,讨论了SVM分类机与通常的所挖掘分类技术的差别、SVM核函数的选择和RBF核函数参数的选择对分类效果的影响。实验结果表明,该系统能有效地检测出新客户的欺诈行为类型,具有很高的分类准确率。     

Spam filtering framework for multimodal mobile communication based on dendritic cell algorithm

With the continual growth of mobile devices, they become a universal portable platform for effective business and personal communication. They enable a plethora of textual communication modes including electronic mails, instant messaging, and short messaging services. A downside of such great technology is the alarming rate of spam messages that are not only annoying to end-users but raises security concerns as well. This paper presents an intelligent framework for filtering multimodal textual communication including emails and short messages. We explore a novel methodology for information fusion inspired by the human immune system and hybrid approaches of machines learning. We study a number of methods to extract and select more relevant features to reduce the complexity of the proposed model to suite mobile applications while preserving good performance. The proposed framework is intensively evaluated on a number of benchmark datasets with remarkable results achieved.     

Study on efficient channel assignment method using the genetic algorithm for mobile communication systems

In cellular mobile communication systems, radio channels are repeatedly used in order to efficiently use assigned frequency bands. The computation time for the optimization of channel assignment increases with the increase of cell number. This paper presents a group channel assignment method for the optimization and its simulation results. This method utilizes the genetic algorithm (GA). Prior to the optimization calculation, whole channel cells are divided into subgroups and then, each subgroup is optimized. Using this result, the whole cells are further optimized. This process enables an efficient calculation to optimize the channel assignment. The results of simulation shows that the proposed method gives a shorter computation time compared with the method called as the individual assignment.     

集成ERP与移动通信平台的移动商务系统设计

为满足企业对移动商务系统的使用需求,对常用ERP系统的数据库和常用移动通信平台的SDK进行分析,在此基础上设计了能够将企业现有ERP系统与移动通信平台集成起来实现移动商务管理的系统。设计了系统架构,将系统分为3层,每层都采用插件技术;根据系统架构设计系统功能,将系统分为7个功能模块,通过这7个功能模块实现该系统的功能;最后设计系统编码,将编码从左到右分为5段,每段有不同的意义和格式要求。     

基于CAN总线的移动机器人通信系统设计

近年来,对移动机器人的研究已成为热点,尤其是对移动机器人数据通信系统的研究。由于CAN总线技术具有网络功能,因此本文利用CAN总线构建了一个移动机器人的数据通信系统,使得机器人内部可以灵活地挂接多个功能模块。本文所设计的移动机器人具有动作模块、语音交互模块、避障与导航模块等。实验表明利用CAN总线技术可以提升移动机器人数据通信的可靠性和可扩展性。     

一种新的移动Agent间通信算法

在分析已有广播通信机制的基础上,提出了一种新的移动Agent间通信算法。通过可靠扩散来实现广播,保证接收者至少接收一次消息;通过接收者主动请求消息,保证接收者只能接收一次消息。新算法保证可靠地完成消息发送以及消息传递的exactly—once语义,并在效率上有了进一步的提高。除了基本的算法,还讨论了一些改进的算法以及实现中遇到的一些问题。     

基于路由优化分组通信技术的改进型层次移动IPv6

在层次移动IPv6中,当移动节点(MN)和通信对端(CN)之间存在更短路由时,二者之间的通信分组仍然要通过移动锚点(MAP)转发,造成了不必要的分组传输时延及系统开销;并且其按照先后顺序进行的域间绑定更新过程有一定的绑定更新时延。为此提出一种改进型层次IPv6,将路由优化分组通信技术应用于层次移动IPv6中,使用条件是分组传输与绑定更新数目比(PBR)达到给定的临界值;同时改进了域间切换的绑定更新流程。理论分析表明,改进型层次移动IPv6相对于层次移动IPv6在系统开销、绑定更新时延及分组传输时延等方面均有优势。     

一种基于移动坐标系的新型节点定位算法

提出一种与距离无关的基于移动坐标系的分布式定位算法,以移动锚节点为原点建立坐标系,未知节点以邻居锚节点信息在临时坐标系中确定自身位置区域,通过在不同坐标系下确定的位置区域取公共集不断缩小自身未知区域,最后利用质心算法求出节点位置坐标。仿真结果表明:新算法拥有较高的定位精度和适度的开销。