一种IEEE1394物理层IP的FPGA原型验证方法

符合IEEE1394协议的物理层IP主要完成总线连接检测、连接管理、仲裁、数据收发等功能,是一款集成高速Ser-des的数模混合SoC。由于在Serdes的测试芯片设计完成前无法对1394物理层IP进行全面验证,因此文中在介绍1394 PHY物理层IP各部分功能的基础上,提出了一种以Xilinx的GTP代替1394物理层Serdes,构建FPGA原型验证平台,采用专用硬件逻辑和软件结合的方式,对1394物理层IP进行充分验证的方法。使用该平台可在Serdes设计未完成前对数字逻辑进行验证,大大缩短物理层IP的开发周期;通过软件控制下的测试项生成、测试过程监控、测试结果判断,可显著提高验证效率。     

全钒液流电池充放电测试系统设计

针对以太网技术在高速图像传输中常见的带宽利用率低,传输协议受限的问题,设计了一种基于可编程逻辑器件FPGA实现千兆以太网传输系统的方案,分析了基于IEEE802.3标准的以太网帧格式和循环冗余校验(CRC),实现了MAC数据包的封装和PHY芯片88E1111的配置,完成了千兆网络系统的设计和高速数据的传输。结果表明,该方案具有成本低,传输速率快且传输协议不受限制的优势,并最终成功应用于某水下高速图像传输系统中。     

基于NS2的IEEE802.15.4协议的研究与仿真

本文在分析IEEE802.15.4协议的基础上,重点研究了星型网络拓扑中在信标使能模式下信标级数的改变、节点数的增加以及发送数据方式的改变对能量剩余、端到端延时、平均分组递交率这三个性能参数的影响,并在NS2仿真环境下进行了仿真。为今后在应用中更好的配置协议和信标级数、以期在开发应用中达到更可靠、节能的效果提供了理论基础。     

基于FPGA的高精度IEEE1588时间戳的设计与实现

简单介绍了IEEE1588协议的时间同步机制,提出了一种在物理层内部标记时间戳的方案,并采用FPGA设计实现了支持时间戳标记电路的10G Base-R PHY,仿真和测试结果表明这种PHY具有最多一个时钟周期的延迟抖动,极大地降低了网络延时抖动对时间同步精度的影响,满足高精度时间同步的要求.     

Towards the performance evaluation of 4th generation wireless communication standards: LTE versus Mobile WiMAX

Advances in wireless communication protocols and networking toward support of the next generation of mobile and radio broadband technologies have contributed to a strong competition among various telecommunication standards in particular Long Term Evolution (LTE) and Mobile Worldwide Interoperability for Microwave Access (WiMAX). In this paper, we provide an in‐depth comparison analysis of LTE and Mobile WiMAX at the physical (PHY) layer by studying the most similar PHY configuration scenarios for these two technologies. Our study includes a throughput analysis of downlink (DL) and uplink (UL) transmissions in time division duplex with the least overhead possible and different antenna schemes as well as modulation and code rates. This study also performs an overhead analysis in both protocols to provide a more in‐depth understanding of the PHY layer capacity in various PHY layer configurations. Our simulation results generally show higher performance for LTE in both DL and UL transmission with 7 Mbps in DL and 5 Mbps in UL, when using one antenna port. However, by increasing the number of antennas for multiple‐input/multiple‐output configurations, the results illustrate a reduction in the performance of LTE compared to Mobile WiMAX. This arises from the increase in reference signal overhead in LTE from 4.7% in single‐input/single‐output (SISO) to 14.28% in 4 × 4 multiple‐input/multiple‐output (MIMO). Copyright © 2013 John Wiley & Sons, Ltd.     

A cross-layer framework for privacy enhancement in RFID systems

In this paper, we introduce a cross-layer framework for enhancing privacy in RFID systems. The framework relies on mechanisms in the physical (PHY) layer, as well as the medium access control (MAC) layer, to provide flexible protection over the unique identifiers of low-cost RFID tags. Such a framework prevents adversaries and malicious parties from tracking RFID tags through the monitoring of their unique identifiers. More specifically, our framework relies on masking of the identifier at the PHY layer, whereby bit-collisions are induced between the backscattered tag identifier and a protective mask, such that a legitimate reader can be allowed to recover the tag identifier but an illegitimate party would not be able to do so. To strengthen the level of protection provided by the bit-collision masking method, we present the randomized bit encoding scheme that is used in our framework. In addition, we also incorporate mechanisms in the MAC layer, and make use of cross-layer interactions between the MAC and the PHY layers to provide flexible privacy protection. This allows tags that do not require privacy protection to be read conveniently while allowing tags that need to be protected to stay protected.     

用以太网物理层芯片实现的雷达远程通信

针对特定环境下雷达数据的远程传输问题,设计一种利用以太网物理层芯片,采用光纤实现的新方法,给出了系统实现的结构框图;讨论了通信协议的制定,并比较了该协议与以太网MAC层协议的异同;给出了系统中关键模块的快速可编程门阵列设计实现和仿真及试验结果。其结果是系统具有实现简单、可靠性高的优点,在雷达数据远程传输中应用前景广泛。     

PECL标准光收发器接口及应用

本文简介ＰＥＣＩ接口电路的最基本的技术，并给出一些 ＰＨＹ　ＩＣ与光收发器接口实例。     

认知无线电系统中基于量子粒子群算法的PHY层及MAC层决策优化

认知无线电技术是下一代通信发展的方向和趋势,同时也是目前通信研究中的热点问题。针对认知无线电系统中,在某一信道条件下其通信系统的物理层（PHY）和媒体链路层（MAC）的基于多个目标来实现优化的问题,基于量子粒子群算法的基本思想,把量子粒子群算法引入认知无线电系统中,并对该算法进行适当的改进,最后基于WSGA控制对电台优化问题进行了仿真,通过仿真证明了其有效性。     

车路互联网的底层协议-802．11p标准

详细地描述了车路互联网系统的底层协议-802．11p标准。将802．11p与传统无线局域网技术进行对比,分析了802．11p在媒体接入控制层（MAC）与物理层（PHY）所做的修改,并从物理层参数、PP—DU帧结构,以及接人优先级等多方面指出了802．11p能在高速移动环境下建立稳定通信链路的原因。其次,还对802．11p所采用的频段、信道、发射功率以及频谱掩模进行分析;最后提出了802．11p在仿真方面所面临的挑战,并且在Simulink上建立了一套动态仿真系统,对标准进行仿真验证。