基于ZigBee和ARM技术的火灾信息数据无线采集系统

为解决目前火灾自动报警及其联动系统信号采集时布线困难,尤其是联动系统信号采集点分散的问题,设计了一套采用ARM处理器、传感器、ZigBee网络、无线通信等技术组成的火灾信息数据无线采集系统。该系统主要由数据采集与控制模块、ZigBee数传模块及传输设备组成。其中数据采集与控制模块负责采集火灾自动报警系统的信息,ZigBee数传模块负责将采集到的数据传送给传输设备,传输设备将接收到的数据通过电话、Internet网或无线网络远传到集中监控中心。经过连接火灾报警联动系统实验,此套系统数据采集准确及时,工作可靠稳定。     

Key distribution system based on identification information

A key distribution system (KDS) based on identification information (ID-based KDS) is presented. The system is founded on the Diffie-Hellman public key distribution scheme and has an identity authentication function. It uses an individual user's identification information instead of the public file used in the Diffie-Hellman scheme. It does not require any services of a center to distribute work keys or users to keep directories of key-encrypting keys. Therefore, key management in cryptosystems can be simplified by adopting the ID-based KDS. Two kinds of identity-based key distribution system are proposed and applied to actual communication networks. One uses two-way (interactive) communication to distribute work keys, while the other uses one-way communication. Modular exponentiations of large numbers, used in the systems, are implemented with digital signal processors.<>     

基于信号空间对齐的网络编码方案

在多用户协同中继系统中,受共信道干扰的影响,系统性能下降严重。提出了一种融合多源信号空间对齐和网络编码的方案,每个用户通过中继向其他的用户发送不同的信息,同时也通过中继接收其他用户的不同信息。整个过程可分为多址接入信道(MAC)和广播信道(BC)两个阶段。在MAC阶段,利用信号空间对齐技术在中继形成较少的信息量、抑制多用户干扰。在BC阶段,通过中继的网络编码,设计简单的预编码算法,有效降低了用户译码的复杂度。整个系统的完成只需要两个时隙,能有效地抑制干扰和提高系统自由度。     

基于RapidIO互联网络的多DSP加载方法研究

针对雷达信号处理系统多处理器、强实时加载的特性,研究了多TS201信号处理系统的网络加载方法。文中提出了一种高效的网络加载方法,充分考虑了系统工作时的总线负载和加载路径的复杂度等因素。此方法加载路径简单,实时性强,通过工程应用验证了该方法的有效性。     

Multiprocessor DSP with multistage switching network for videocoding

A dynamic load balancing method is proposed that uses a multistage switching network to solve the problem of load concentration on certain processors for video coding in multiprocessor digital signal processors. (DSPs) This method balances the processing load by distributing the total load among the processor elements having smaller loads. The load distribution is performed by the multistage switching network, which transmits the load quantity information within the network. A scheduling method for a motion picture coding algorithm using multiprocessor DSPs is also proposed. This scheduling method takes full advantage of the multistage switching network functions when distributing the processing load and sorting the processed results. By using computer simulation, multiprocessor DSP performance with the proposed method is shown to be double that of a conventional multiprocessor DSP when an initially unbalanced load is allocated to the processors, as in picture coding for TV conferences     

The TMS320 family of digital signal processors

This paper begins with a discussion of the characteristics of digital signal processing, which are the driving force behind the design of digital signal processors. The remainder of the paper describes the three generations of the TMS320 family of digital signal processors available from Texas Instruments. The evolution in architectural design of these processors and key features of each generation of processors are discussed. More detailed information is provided for the TMS320C25 and TMS320C30, the newest members in the family. The benefits and cost-performance tradeoffs of these processors become obvious when applied to digital signal processing applications, such as telecommunications, data communications, graphics/image processing, etc.     

Wireless broadcast encryption based on smart cards

Wireless broadcasting is an efficient way to broadcast data to a large number of users. Some commercial applications of wireless broadcasting, such as satellite pay-TV, desire that only those users who have paid for the service can retrieve broadcast data. This is often achieved by broadcast encryption, which allows a station securely to broadcast data to a dynamically changing set of privileged users through open air. Most existing broadcast encryption schemes can only revoke a pre-specified number of users before system re-setup or require high computation, communication and storage overheads in receivers. In this paper, we propose a new broadcast encryption scheme based on smart cards. In our scheme, smart cards are used to prevent users from leaking secret keys. Additionally, once an illegally cloned smart card is captured, our scheme also allows tracing of the compromised smart card by which illegal smart cards are cloned, and can then revoke all cloned smart cards. The new features of our scheme include minimal computation needs of only a few modular multiplications in the smart card, and the capability to revoke up to any number of users in one revocation. Furthermore, our scheme is secure against both passive and active attacks and has better performance than other schemes.     

基于GIS的有线电视资源信息系统分析与设计

本文基于地理信息系统（GIS）技术,通过对有线电视网络资源管理系统功能需求和建设需求分析,进行功能及运行模式设计,并对系统中主要的技术问题进行研究,提供了相应的解决方案。     

基于LabVIEW与Matlab的实时在线光子多普勒测速系统

传统的光子多普勒测速系统中,速度信息的获得都采用离线处理,处理周期长,导致该传感系统不能实时应用。从光子多普勒速度测量系统的原理出发,结合LabVIEW的图形化语言设计和Matlab强大的数值处理能力,以数据采集卡和PC机为采集和处理平台,提出并设计了一种信号采集和处理系统,实现了测速信号的实时数据采集、在线处理和显示。     

一种高效的具有用户匿名性的无线认证协议

提出了一种高效的具有用户匿名性的无线认证协议。利用Hash函数和Smart卡实现了协议的用户匿名性。协议充分考虑了无线网络自身的限制和移动设备存储资源及计算资源的局限性，在认证过程中移动用户只需要进行一次对称加密和解密运算，用户与访问网络、本地网络与访问网络都只进行一次信息交换，而且所有对称加密都使用一次性密钥。本协议具有实用、安全、高效的特点。     

基于多级分布式银行的Smart Card电子支付系统

在电子支付系统中,采用分布式电子银行方案更适合于网络运行环境,然而在现行的分布式电子银行方案中,每个用户局限在所开帐户的电子银行取得签发的Smart Card和提取或存储电子货币,由于网络的瓶颈作用和安全缺陷,以及用户所处地域的分散性和流动性等因素的限制、使得单一开户的银行方案在实际应用中其分布式特性并未充分得以发挥。针对此,通过采用代理签字与群签字综合的方法,本文提出了多级电子银行的新方案,并对该方案的安全性进行了分析。     

Database Optimizations for Modern Hardware

Databases are an important workload for modern commodity microarchitectures. Achieving the best performance requires that careful attention be paid to the underlying architecture, including instruction and data cache usage, data layout, branch prediction, and multithreading. Specialized commodity microarchitectures, such as graphics cards and network processors, have also been investigated as effective query coprocessors. This paper presents a survey of recent architecture-sensitive database research. The insights gained from optimizing database performance on modern microarchitectures are also applicable to other domains, particularly those that are similarly data intensive.     

Optimum VoIP packet routing using a communications processor

This article presents a new architecture for the VoIP media gateway using only a communications processor and digital signal processors. The new architecture can be used by telecommunications equipment manufactures to replace a network processor and a general-purpose processor with a single communications processor, thereby can reduce the system cost, power consumption, printed circuit board (PCB) area, software complexity and time to market. In the new architecture the modules are interconnected via Ethernet interfaces, which make voice packet encapsulation possible in digital signal processors. This relieves the network processor, which in voice over IP (VoIP) media gateways is most commonly used for the routing of VoIP packets and voice-packet encapsulation, and means it can be replaced by a communications processor. The presented media gateway architecture makes it possible to combine the data- and control-plane application on a single-communications processor, but only in the case of a properly optimized program code and an optimized Ethernet driver. Therefore, the main part of the article is dedicated to a presentation of the methodology for the analysis and optimization of the presented systems. In order to support this methodology, a new tool named performance monitor (PM) was developed. The PM tool is presented here, and was used for optimizing the Ethernet driver. The Ethernet driver was optimized and modified in such a way as to put a minimal load on the microprocessor core of the communications processor when routing the VoIP packets to digital signal processors and back. The article ends with a presentation of the experimental optimization results, which were acquired from a real telecommunications system.     

Research on space focusing virtual coverage based on orthogonal frequency time reversal method

To solve the problem of information leakage and coverage efficiency in ultra-dense wireless network,the orthogonal frequency-time reversal virtual coverage scheme was proposed.At first,different wireless reversal channels with lower correlation were distinguished by orthogonal carries.Next,after time reversal,the space focusing of each target signal was realized around the terminal.Then,theoretical expressions of the signal coverage and the signal-interference-to-noise ratio were derived and proved.Ultimately,the virtual coverage was shaped,meeting the requirements of users.The coverage of unrelated user not belonging to system was reduced.The results show that those unrelated users are difficult to receive the target signal because of virtual coverage.In addition,the system has higher capacity and security rate of reliable transmission without any more power or antennas.     

可光纤集成的相干态量子身份认证系统

报道了可光纤集成相干态量子身份认证实验系统。该系统采用偏振相干态的斯托克斯矢量作为量子信号载体,采用动态偏振控制器作为信号调制器,利用固有的相干态量子噪声保证系统的安全性。自行设计了脉冲激光驱动电路、微弱窄脉冲激光探测电路、信号同步模块,采用Socket网络通信程序在TCP/IP局域网中实现了量子保密通信所需要的经典通信。该相干态量子身份认证系统采用的运行密钥为12位,每个光脉冲包含40000个光子,传输速率达到8kbit/s,合法用户间误码率(BER)小于10-4。每传输一个比特信息,攻击者所能窃取的信息量I(Alice,Eve)<10-14bit。     

Anonymous credit cards and their collusion analysis

Communications networks are traditionally used to bring information together. They can also be used to keep information apart in order to protect personal privacy. A cryptographic protocol specifies a process by which some information is transferred among some users and hidden from others. We show how to implement anonymous credit cards using simple cryptographic protocols. We pose, and solve, a collusion problem which determines whether it is possible for a subset of users to discover information that is designed to be hidden from them during or after execution of the anonymous credit card protocol     

用MEMS光开关实现高性能光互连网络

建立了1Gbps传输结构的高性能光互连网络，来提高计算机群系统的网络性能。它利用微机电系统(MEMS)光开关和PCI总线全带宽网络接口卡构成光互连链路。全带宽PCI接口卡总线峰值传输速率为132Mbytes／s，光信号传输速率可达1Gbps以上。用MEMS制做的全光开关减少了光—电之间的转换，提供的开关方式与数据的波长、速率和信号格式无关。因而，利用这种网络结构，可以最大限度地减少网络延迟和网络通信开销，极大地提升了机群系统的总体性能。     

基于高精度采集卡的医院机房供电监控系统设计

针对当前医院机房供电监控系统对电力的依存度越来越高,无法保障医院机房供电室安全,系统并发用户数量较少,兼容性较低的问题,设计了基于高精度采集卡的医院机房供电监控系统。通过通信网络连接系统框架的前置采集端和监控管理,硬件设计包括前端采集设备、通信传输硬件、监控管理硬件,软件设计主要包括用户登录模块、实时监测模块、通信传输模块和门禁管理模块。系统测试结果表明:系统性能测试和功能测试均符合预期结果,系统并发用户数量较多,兼容性较高,可以用于医院机房供电监控,保障医院机房供电室安全。     

基于CPLD实现脉搏信息采集及处理系统

文中主要研究并设计了人体脉搏信息采集及处理系统,设计中采用PVDF压膜式脉搏传感器[3]和Altera公司的MAX II EPM1270处理器,该脉搏传感器具有灵敏度高、性能稳定可靠等优点。传感器采集的脉搏信号经过低噪声放大和高速AD转换,最后通过UART串口输出。CPLD通过UART异步通信方式实现对脉搏信号的采集,并对人体脉搏进行计数。当人体每分钟的脉搏数低于60次或者高于120次时系统能驱动蜂鸣器实现报警功能,同时液晶1602显示当前的脉搏次数。