一种神经网络判决反馈均衡器

在分析Chebyshev正交多项式神经网络非线性滤波器的基础上,利用判决反馈均衡器的结构特点,提出了一种Chebyshev正交多项式神经网络判决反馈均衡器,给出了对应的自适应NLMS算法.数值仿真结果表明,该均衡器结构能够更有效地消除码间和非线性干扰,降低信号的误码率.     

非线性通信信道的神经FIR自适应幅值Laguerre均衡器

针对数字通信系统中线性和非线性信道干扰问题,在分析神经FIR滤波器、判决反馈结构和Laguerre滤波器的基础上,提出了神经FIR自适应幅值判决反馈均衡器和神经FIR自适应幅值Laguerre均衡器.其中神经FIR自适应幅值Laguerre均衡器结构简单,具有IIR和FIR滤波器特点,能够使用较少的阶数达到较好的均衡效果,且理论分析证明该均衡器是稳定的(0相似文献   

基于UKF的自适应DFE信道均衡

针对信道的线性和非线性失真,在分析简化的非线性滤波的基础上,利用判决反馈的结构特点对其进行扩展,提出了基于UKF滤波的判决反馈均衡器,仿真表明,UKF滤波算法能降低系统均方误差性能。     

基于小波包变换的非线性信道均衡器

针对严重线性失真和轻度非线性失真的数字信道，为了提高基于最小均方误差算法的判决反馈均衡器的收敛速度，首先提出用一族正交小波包基函数来表示非线性信道判决反馈均衡器厦其输出，然后给出基于小渡包变换的非线性信道自适应均衡算法。该算法实现了小波包与非线性信道模型的结合，在计算量增加不多的前提下，利用小波包对小波空间的进一步划分以厦比小波变换更强的去相关能力来减小输入信号相关阵的条件数。对典型非线性信道模型的仿真结果表明，该算法可有效提高均衡器的收敛速度。     

一种组合神经网络非线性判决反馈均衡器

1 引言数字通信系统的典型模型如图1所示,发送序列s(n)经信道传输后因发生失真及噪声v(n)的影响而成为畸变信号x(n),为此需用均衡器对其进行均衡以恢复发送序列。目前,自适应均衡已成为数字通信中一种非常重要的技术,自适应均衡器的构成也是多种多样,其中最简单的是线性横向均衡器(LTE)和判决反馈均衡器(DFE),它们都比较适用于线性信道。如果信道呈现非线性特性,两者的性能特别是LTE的均衡能力会大大下降,而利用径向基函数网络(RBFN)等构     

基于FPGA的判决反馈均衡器的设计与实现

本文简述了判决反馈均衡器的基本原理和实现方式,为满足实现均衡器的可配置需要,专门针对判决反馈均衡器的复杂结构,提出一种采用自下而上的模块化设计方法,对系统的各个模块设计都进行了详尽的分析,并讨论了需要注意的要点。     

Turbo-均衡及迭代均衡的结构模型

给出了Turbo-均衡、硬迭代判决反馈均衡器、软迭代判决反馈均衡器和分步迭代判决反馈均衡器的结构模型,并对这些模型进行了分析和对比。     

Legendre神经网络非线性信道均衡

在分析Chebyshev正交多项式神经网络非线性滤波器的基础上，利用Legendre正交多项式快速逼近的优良特性以及判决反馈均衡器的结构特点，提出了两种新型结构的非线性均衡器，并利用NLMS算法，推导出自适应算法．仿真表明，无论通信信道是线性还是非线性，Legendre神经网络自适应均衡器与Chebyshev神经网络均衡器的各项性能均接近，而Legendre神经网络判决反馈自适应均衡器能够更有效地消除码间干扰和非线性干扰，误码性能也得到较好的改善．     

独特字块结构的单载波时频混合均衡器设计

在单载波块传输系统中,提出了一种更适用于基于独特字块结构的时频混合判决反馈均衡器的设计方法。该方法利用独特字的已知特性,在接收端将经过信道的独特字和有用数据分开,再进行均衡处理,恢复出原始数据。根据这一方法,给出了基于独特字块结构的判决反馈均衡器的最优结构和次优结构。仿真结果表明,基于独特字的最优结构时频混合判决反馈均衡器相比传统基于循环前缀的时频混合均衡器性能有很大的提升;复杂度降低的次优时频混合判决反馈均衡器的误码性能仍要好于基于循环前缀的均衡器。     

FTN系统中两种频域迭代分组判决反馈均衡器仿真分析

超奈奎斯特(FTN)码元速率传输系统可以有效提高数据传输速率,但该系统在接收端引入了无限长的码间串扰(ISI),从而增加了接收复杂度。为此,分析两种能降低FTN系统计算复杂度的频域均衡器,即频域迭代分组判决反馈均衡器(IBDFE)和低复杂度迭代分组判决反馈均衡器(LC-IBDFE)。将IBDFE和LC-IBDFE分别扩展到加性高斯白噪声(AWGN)信道和频率选择性衰落信道中。仿真结果表明,这两种频域均衡器可以应用到衰落信道中,且在多径数目不大的情况下,两者的误码率和AWGN信道条件下十分接近。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。