Energy-efficient Hardware Accelerators for the SA-DCT and Its Inverse

The explosive growth of the mobile multimedia industry has accentuated the need for efficient VLSI implementations of the associated computationally demanding signal processing algorithms. In particular, the short battery life caused by excessive power consumption of mobile devices has become the biggest obstacle facing truly mobile multimedia. We propose novel hardware accelerator architectures for two of the most computationally demanding algorithms of the MPEG-4 video compression standard––the forward and inverse shape adaptive discrete cosine transforms (SA-DCT/IDCT). These accelerators have been designed using general low-energy design philosophies at the algorithmic/architectural abstraction levels. The themes of these philosophies are avoiding waste and trading area/performance for power and energy gains. Each core has been synthesised targeting TSMC 0.09 μm TCBN90LP technology, and the experimental results presented in this paper show that the proposed cores improve upon the prior art.

Layered Access Control Schemes on Watermarked Scalable Media

Intellectual Property (IP) protection is a critical element in multimedia transmission and delivery systems. Conventional IP protection on multimedia data can be categorized into encryption and watermarking. In this paper, a structure to perform layered access control on scalable media by combining encryption and robust watermarking is proposed, implemented, and verified. By taking advantages of the nature of both encryption and watermarking, copyrights of multimedia contents can be well protected and at the same time, multiple-grade services can be provided. In the summated examples, we assume a scalable transmission scheme over the broadcasting environment and use it to test the effectiveness of proposed method. When the embedded watermark is extracted with high confidence, the key to decrypt the next layer can be perfectly recovered. Then, the media contents are reconstructed and the copyrights are assured. The application examples also demonstrate the practicality of the proposed system.

相关法旁瓣对消抗有源压制干扰分析及仿真

介绍了一种相关法旁瓣对消抗干扰技术,对其系统组成及基本工作原理进行了分析,建立了系统电路仿真模型,最后,给出了此系统对几种有源压制干扰的对消结果。结果表明,该系统对抗有源压制干扰有很好的效果。     

Study and simulation of vibrating target's motion states based on Doppler lidar

激光雷达微多普勒效应在对目标探测、识别中测量精度高、抗干扰能力强,比传统微波雷达拥有更高的空间分辨率和灵敏度.本文基于激光探测,从理论上分析了振动物体在行进过程中产生的多普勒和微多普勒效应.建立典型运动模型,通过目标信号的频移图和频谱图可以很好地观测物体运动状态、分析振动特性.最后,在simulink下进行过程仿真并验证其有效性,对目标的识别和运动特性提取起到积极的作用.     

BaCO3基低温共烧陶瓷基板工艺及性能分析

对用于封装的BaCO3基低温共烧陶瓷基板LTCC材料进行了研究,包括组分配制以及陶瓷制备工艺研究。对烧结后陶瓷的部分热性能以及力学性能进行了测试。结果表明:BaCO3基低温共烧陶瓷较为致密的密度在3.8～4.2g/cm3,在900℃烧结的陶瓷机械形变较小。     

基于TDA1521的低频治疗仪放大器的设计

在医用理疗设备中,低频治疗信号通常为占空比、幅度可调的低频(100~200 Hz)脉冲信号。其放大器的设计可选用的芯片很多。低频治疗仪的放大电路是低频理疗设备的基本电路,本设计选用Philip生产的著名音响放大集成电路TDA1521,用于低频治疗仪的功率放大电路,经过测试,满足了设计的需要。     

4G关键技术研究

随着用户对移动通信系统的速率要求不断提高,3G系统实际所能提供的最高速率已不能满足未来市场的实际需求,因而在3G系统还没有大规模投入商用的情况下,国内外移动通信领域的专家已经在进行4G系统的研究和开发工作.4G是多功能集成的宽带移动通信系统,具有许多关键优势,因而已成为移动通信领域的研究热点.文章给出了4G的体系结构,并对4G相关技术的原理进行了详细分析.     

短波突发通信快速同步技术研究

对PN序列的捕获问题,介绍了串行捕获和并行捕获两种方案,在此基础上介绍了一种改进的门限自适应的快速同步技术,适用于短波高速数据传输。     

IEEE802.11s路由协议漏洞与攻击

IEEE802.11s是IEEE关于无线Mesh网络的规范。802.11s虽然沿用了IEEE802.11i的安全规范,但是对于路由协议的安全并没有做过多的定义,由此产生了一定的安全隐患。文章分析了IEEE802.11s标准(草案)中的路由协议的漏洞,并针对IEEE802.11s中使用的混合无线网状网协议(HybridWirelessMeshProtocol,HWMP)设计了两种攻击方式,从而破坏无线网状网络的可用性。通过在自行设计的路由器平台上实现无线攻击,并分析攻击对网络造成的影响来验证安全漏洞的存在性和可利用性。     

利用CAN总线和组态软件构建计算机监控系统

提出了基于CAN总线和组态软件的机务段检修设备的监控系统的总体方案。在方案中,将工业控制计算机同时置入了TCP/IP协议的高端管理层网络和CAN总线协议的监控网络层中,实现了对机务设备的高精度监控。