变带宽存储中齐次位移边界条件混合处理法

本文讨论变带宽存储中齐次位移边界条件混合处理法,给出IBM PC FORTRAN77程序。     

CPPMB：一种新的多处理机互连网结构

本文提出了一个新的多处理机互连网结构（ＣＰＰＭＢ系统结构），该结构适合于中大规模的多处理机系统，并同时分析了它的有效存贮器带宽性能，获得的模型基于各处理机拥有若干偏爱存贮器模块。为了验证模型的正确与否，进行了相应的仿真实验，结构表明：当处理机发给属于同一个群的各存贮器模块的访存请求较高时，该系统具有极好的性能。另外，本文还对它的效费进行了评价并且与其它系统比较。     

Optimal design of basic pulse waveforms for THSS UWB radio systems

1.INTRODUCTION Recently,therehasbeenagreatinterestinUWBra dioforfuturehighrateshort rangewirelesscommu nications[1～4].Forhighlyresolvingmultipathand generatingUWBsignalswithrelativelylowcomplexi ty,UWBradiosystemsusuallyuseTHSSimpulse trainwithPPMtocarrydatainformation[5,6].That iswhyitissometimescalledimpulseradio(IR).The essenceofUWBradioisthatitdoesnotuseasinu soidalcarrierbutinsteadcommunicateswithaTHSS basebandsignalcomposedofsubnanosecondpulses withPPM.Thatis,UWBra…     

On UWB system performance under impulsive noise environment

In this paper, the performance of UWB (ultrawide bandwidth) radio systems under impulsive noise environment (INE) is investigated. At first, the Middleton's class a model is used as a model of impulsive noise (IN), we investigate the statistical characteristics of in-phase and quadrature components of IN, and it is proved that unlike Gaussian noise (GN), they are dependent especially to IN with small impulsive indices, Then, making use of this dependence between in-phase and quadrature components, an ovel UWB radio receiver designed for IN is proposed. The exact expression for the average BER (bit error rate) of this receiver, which is a function of SNR (signal to noise power ratio) and threshold value, is derived. Thirdly, we'll discuss the optimum threshold value. We'll also estimate the performance of UWB radio systems with the proposed receiver designed for IN and with the conventional receiver designed for GN in INE. Numerical results show that the performance achieved by the proposed UWB radio receiver is much etter than that of the conventional UWB radio receiver. Meanwhile, it is shown that both impulsive index and threshold value have much effect on the performance of UWB radio system s under the condition of INE     

随机信号的非线性变换及其频谱特性的分析

本文介绍和分析平稳随机信号的非线性变换及其频谱关系。对于输入信号为高斯平稳随机过程的情况,讨论无记忆非线性系统及一类有限记忆非线性系统的响应以及经过非线性变换后的频谱特性,并详细分析非线性系统函数的特性和使用条件。另外,也对某些非高斯平稳随机信号的非线性变换及其频谱特性进行了分析。指出非线性变换对随机信号具有白化作用并给出频谱带宽的关系。最后,采用本文讨论的方法给出几组实际模拟的结果。     

认知可用带宽下的传输控制机制

在航空通信中,传输控制技术直接影响网络的通信性能。基于优先级的传输控制机制能够保证高优先级业务的通信性能,但存在低优先级业务传输性能不佳以及带宽资源利用不足的问题。为了解决这一问题,结合绿色通信理论思想和可用带宽估计技术,提出"认知可用带宽"概念,设计基于认知可用带宽的传输控制机制,并采用多进制自适应调制技术提升网络带宽利用率。仿真结果表明,基于认知可用带宽的传输控制机制能够在保证高优先级业务时延的条件下改善低优先级业务的传输性能,并保证业务最大时延抖动小于0.02ms;同时,自适应调制技术的应用使得网络吞吐率提升3.26%。     

ADSL数字传输技术与应用

本文较详细地介绍了采用非地称数字用户线进行数字传输的工作原理，及如何应用该项技术使用户在ＡＴＭ网络上动态获得多项不同带宽的服务。     

一种基于多媒体流平滑磁盘系统带宽的方法

针对多媒体数据量变化范围大、变化频率高,存储系统读取流数据时会造成读取速率不断变化,影响多媒体流的服务质量的问题,采用存储带宽平滑方法,根据特定多媒体流本身的特点对多媒体流进行平滑,有效地降低多媒体流数据本身对系统的影响,提高了系统的服务质量.     

HFC宽带接入技术的研究与应用

接入网作为通信网中与用户相连的最后一段网络，已经成为宽带网络技术的一大热点.简单介绍了目前主要的宽带接入技术，着重对HFC（光纤同轴混合）接入技术及应用于现代远程教学进行了研究，并给出了详细的系统设计方案.     

New bandwidth algorithmand its performance analysis in integrated service network

1 .INTRODUCTIONATMis one of main technologies in wide multi mediatelecommunication network because of supporting allkinds of services and having strict assuring mecha-nismof quality of service (QoS) .ATMtechnologyisconnection-oriented which must first establish a virtu-al path (VP) before transferringinformationin orderto guarantee QoS. Connection admission control(CAC) is afunction which determines whether to ad-mit or reject connection requests . A connection re-quest includes traf…