基于USB的GPS数据采集系统

介绍了一种基于USB的GPS数据采集系统软硬件设计方案,以FPGA为该系统的控制核心、CY7C68013为USB接口芯片实现FPGA与上位机之间的数据传输.针对FLASH中的坏块问题,提出了一种FLASH坏块检测及管理方案.采用双缓冲技术,解决了采集系统中的数据丢失问题.该系统实时传输速率达4 Mbit/s,而且可支持更高的传输速度.     

一种混合WDM网络的实时传输策略

波分复用(Wavelength Division Multiplexing,WDM)网络应用于实时性网络环境的关键因素是实时传输策略。在混合式WDM网络结构中,研究了子网内的实时调度和子网间的路由策略。其中子网内为星形耦合式WDM网络,分析了区分丢弃-最早时限优先调度法(DDS-EATS)的不足,针对多消息多次调度的问题提出了改进方案。子网间网络采用洗牌型WDM波长路由网,消息路由采用轻载固定路由,重载流量疏导的方法。最后在OPNET仿真平台上,验证了该传输策略下消息的实时传输性能和多次消息调度中改进算法的网络延迟和网络利用率的网络性能。     

视频成像测井光缆传输系统井上电路设计

文章描述了一种基于FPGA实现的井上电路.该电路基于光缆传输机制,采用光模块完成光电转换,在FPGA内实现高速串行数据的数据恢复和曼彻斯特解码等处理,经视频模块处理后,完成对井下视频信息的恢复.其中,高速串行数据的数据恢复采用了过采样的处理方法.该电路结构简单、可靠性较高,与井下电路配合使用,可实现井下视频信号的可靠采集.     

重庆东环传输网的规划与建设

基于重庆东环传输网的规划及建设过程介绍，着重对设备选型和网络结构优化进行了论述。     

Progressive meshes transmission over a wired-to-wireless network

The evolution of mobile network and the popularization of mobile devices; the demand for multimedia services and 3D graphics applications on limited resource devices is more contemporary. Most of the works on multimedia transmission are focused on bit errors and packet losses due to the fading channel environment of a wireless network. Error resilient multimedia is significant research topic which can be adapted to the different conditions in a wireless environment. The current solutions in transmission of multimedia across different networks include some type of transcoder where the source is partially or fully decoded, and re-encoded to suit the network conditions. This paper introduces a flexible progressive coding framework for 3D meshes, which can be adapted to the different conditions imposed by wired and wireless channels at the bitstream level. By avoiding the computationally complex steps of transcoding between networks, could deteriorate decoded model quality. The framework also allows refined degradation of model quality when the network conditions are poor due to congestion or deep fades. Xiaonan Luo, male, born in Feb. 1963 in Jiangxi Province, China, Ph. D., completed his post-doctorate training in Mar. 1995. He is a professor and Ph. D. advisor of the School of Information Science and Technology, and the Chairman of Computer Application Institute of Sun Yat-sen University. His current interests are in mobile graphics transmission and 3D geometric simulation methods. He enjoys the government special allowance granted by the State Council of China. He won the National Science & Technology Progress Prize awarded by the Ministry of Science and Technology of China and the National Natural Science Funds granted by the National Nature Science Foundation of China. Guifeng Zheng, male, born in Jan. 1977 in Guangdong Province, China, Ph. D., received his Ph.D. degree from Sun Yat-sen University in 2005. He is currently an research assistant in the Computer Application Institute of Sun Yat-sen University. His research interests span the areas of wireless networks and mobile graphics computing.     

40 Gbit/s波分技术发展及应用探讨

40 Gbiffs传输是近年来业界关注的焦点之一,本文从全球40 Gbit/s发展趋势、40 Gbit/s传输的市场需求、40 Gbit/s技术及建设成本、光缆性能等方面进行了综合分析,认为以40 Gbids为基础的WDM系统已经趋近成熟并进入规模商用阶段.各运营商应根据自身的实际情况选择适合的网络建设方案.     

混合发射天线选择的等增益传输系统优化设计

文中研究了混合发射天线选择的等增益传输(TAS-EGT)系统优化设计问题.根据信道衰落系数的排序统计特性,给出了TAS-EGT系统的平均接收信噪比,提出了最小发射天线数的计算方法.由于TAS-EGT系统的性能并非完全正比于射频链路数,因此文中提出了最优射频链路数的计算方法.仿真结果显示增加少量的发射天线可以节省大量的射频链路.因此,文中提出的算法可以降低系统的成本和复杂度,优化系统的性能以减少不必要的开销.     

Experimental investigation of hollow-core photonic crystal fibers with five photonic band-gaps

The hollow-core photonic crystal fibers （HC-PCFs） with integrity structure have been fabricated with an improved twice stack-and-draw technique. The transmission spectrum shows that five photonic band-gaps within 450-1100 nm have been obtained.And the green fight transmission in the HC-PCFs has been observed remarkably.     

随钻测井数据声波遥传系统研究

随钻测井数据传输是实现智能化钻井的荚键技术之一,声波遥传技术是利用沿钻柱系统传播的弹性波为载波,将测量数据传输到地面的一种随钻数据传输技术,是一种新兴的、非常有发展前途的随钻数据遥传技术。然而,钻井过程中由钻井设备、泥浆的循环等产生的声波噪声以及信号在介质中传播的衰减吸收,特别是钻杆接头的高反射性,使得钻柱的脉冲响应持续达数酉毫秒,这将造成严重的码间干扰,并最终导致信道的传输能力的大幅下降。针对这一难题,该文在深入分析钻柱系统的声传播特性的基础上,提出基于SC—FDE技术的声波无线传输通信系统模型,并研究适合于声波传输信道特性的信道编译码技术以及随钻数据的调制解调技术,降低误码率、提高传输的可靠性。     

高清DSNG新闻采访卫星车系统集成

青海广播电视台于2011年10月开始建设高清DSNG新闻采访卫星车,现已完成集成验收工作.高清DSNG新闻采访卫星车系统由卫星传输系统和音视频系统两部分组成,着重从链路计算、设备选型、系统构成、技术指标、系统监控等方面介绍了卫星传输系统.