信号串扰对高速模数转换器性能影响的分析

基于实际电路的模数转换系统建立性能分析模型,分析电路信号串扰对转换时钟的干扰,并对转换时钟在信号串扰和噪声影响下的模数转换性能进行研究,推导出有信号串扰时的时钟抖动的模数转换解析表达式,证明转换结果含有和串扰信号频率相关的无穷多项高次谐波分量,并会导致模数转换器性能降低.仿真结果证明了相关分析的正确性,通过试验进一步说明了电路信号串扰对模数转换结果的影响.     

经验模态分解算法在角位移传感器信号去噪中的应用

当多个角位移传感器工作在多个电平时,线路间的串扰会导致内部噪声,影响传感器信号输入和输出。设计了角位移传感器线间串扰信号的多层分解去噪方法。在计算角位移传感器信号线间的串扰电压后,分别计算电容耦合和电感耦合的总串扰电压。利用经验模态分解算法对传感器信号进行逐层分解后,得到一定量的残差项和信号分量（IMF）,并将其相加生成新的信号。重复分解计算产生新的信号,然后计算信号分量（IMF）中包含的串扰信号,并根据硬/软阈值消除串扰噪声。仿真结果表明,所设计的方法可以有效地消除角位移传感器线间串扰信号噪声的影响,使传感器采集的角位移测量电路的电压信号更接近无串扰的电压信号,从而保证角位移传感器信号的有效性。     

串扰目标识别框架

提出了一个全面识别静态和动态串扰噪声的算法框架,在静态串扰噪声的识别中,通过静态串扰噪声的峰值以及噪声宽度信息来识别串扰目标。在动态串扰噪声的识别中,引入了混合时序分析,缩小了时间窗区间,并通过测试生成来验证信号间的逻辑关系,通过这些准确的时序及逻辑信息,识别出串扰目标。     

针对线间串扰现象的静态定时分析

超深亚微米工艺下，线间串扰是导致电路故障的主要原因之一。尽管可能导致故障的线间串扰的数量巨大，但真正会引起故障的线间串扰却相对较少。因此，如果能在对电路验证或测试前进行静态定时分析，找出那些导致电路故障的线间串扰，则可以有效提高测试生成效率，并降低测试成本。基于此目的，文章在静态定时分析中引入对线间串扰 扰现象的分析，在线时延模型的基础上使用重叠跳变对故障模型，只需要求出与最长通路的重叠跳变对即可。在对ISCAS89基准电路的实验中，各电路需要测试的串扰数平均减少至10％以下。相对于已发表的实验结果，本文的实验结果具有较高的CPU效率。     

深亚微米集成电路设计中串扰分析与解决方法

本文介绍了深亚微米集成电路设计中串扰的成因及其对信号完整性的影响,论述了串扰分析和设计解决的一般方法,对于实际设计具有一定的理论指导意义和应用参考价值。本文最后指出了我们工作的进一步研究方向。     

动态串扰噪声识别算法

提出了动态串扰噪声的识别算法.针对基于传统静态时序分析的结果过于保守的缺点,本算法引入了混合时序分析,缩小了时间窗区间,为动态串扰噪声的识别提供了准确的时序信息,与此同时,通过测试生成来验证信号间的逻辑关系,根据这些准确的时序及逻辑信息,识别出动态串扰噪声.     

针对串扰引起的时延故障的测试产生

串扰的出现可能会导致电路出现逻辑错误和时延故障．因此，超深亚微米工艺下，在设计验证、测试阶段需要对串扰问题给予认真对待．由于电路中较长的通路具有较短的松弛时间，因此容易因为串扰问题产生时延故障．针对这类故障给出了一个考虑较长通路上串扰现象的时延故障测试产生算法，该算法采用了波形敏化技术．实验结果表明，采用文中的技术可以对一定规模的电路的串扰时延故障进行测试产生．     

无码间串扰的发射接受成型滤波器设计

介绍数字基带传输特性，分析影响基带脉冲传输特性的基本因素，并提出了解决方案；根据其传输原理，提出设计了无码间串扰的发射和接收成型滤波器的基本模型；对无码间串扰的发射和接收成型滤波器进行了数字仿真计算和分析。仿真结果对滤波器的模型设计与参数分析有着重要参考价值。     

基于优先性的延迟噪声故障分析方法*

为了减少互连串扰噪声对电路性能的影响,提出一种top-k延迟噪声故障分析方法。通过逻辑分析方法有效地修剪受扰线和干扰线组合的分析空间,利用时序窗口计算受扰线和干扰线之间的虚假延迟噪声故障的发生概率,找到实际电路中最有可能引起虚假延迟噪声故障的top-k条干扰线。本方法能够在规定时间内消除尽可能多的虚假噪声,从而提高了串扰噪声影响下时序分析的精确度。     

神经元网络语音增强方法及DSP实现

在噪声环境下双麦克风语音增强应用中,由于麦克风之间存在交叉串扰,传统自适应对消算法降噪性能受到极大的哪影响.为了提高降噪系统性能,提出了一种基于神经元网络双麦克风自适应抗交叉串扰语音增强方法.该方法通过设置两级自适应算法,消除了麦克风之间的交叉串扰,其中自适应算法均采用神经元网络对消方法.算法仿真基础上,运用DSP制作了实时降噪处理样机.测试结果表明,采用新方法后,系统噪声抑制性能得到了很大的提高.     

多用户VDSL2系统远端串扰抵消算法

随着宽带接入网速率提升,VDSL2技术成为最后一公里的主流接入方式。用户数量急剧增加使传输线路之间串扰成为制约VDSL2系统性能的重要因素,线路之间串扰分为近端串扰（NEXT）和远端串扰（FEXT）,VDSL2系统采用正交频分复用调制技术,近端串扰可以通过滤波器滤除,远端串扰却无法消除。主要研究VDSL2系统远端串扰噪声消除的方法,提出远端串扰噪声如何进行评估和计算,推导出远端串扰噪声计算公式,通过公式可以计算出每条线路受到其他线路串扰噪声的大小,然后发送信号时通过串扰噪声预抵消运算,接收到的信号就能成功消除串扰噪声的影响,提高了接收信号的SNR值,进而提升了VDSL2传输速率。     

A blind detection-guided approach for normalised multi-modulus crosstalk estimator in sparse multi-user DSL channels

In high-speed digital subscriber lines (DSL), far-end crosstalk is the main limiting factor on data rates. However, most of the crosstalk is due to the neighbouring twisted pairs in the binder. Therefore, the crosstalk channel matrix is sparse. Using Level 3 of Dynamic Spectrum Management, users are co-ordinated at the central office to cancel the crosstalk. Means for estimating the crosstalk canceller matrix are of critical importance for the cancellation to prove effective. Preferably, the estimation procedure should have low overhead both in computation and bandwidth. Normalised least mean squares (NLMS) based adaptive crosstalk cancellers (Gujrathi et al. (2009) [1]) have a low computational overhead but use a training sequence to ensure they converge adequately. However, using a training sequence consumes some amount of bandwidth which can be avoided if an unsupervised or blind algorithm like a normalised multi-modulus algorithm (NMMA) is used instead. A limitation of NMMA is that its convergence time is often longer than that of the NLMS algorithm. Furthermore, this is made worse as the number of canceller coefficients is made larger. In application to adaptive crosstalk cancellation within the multi-user DSL binder-channel, we argue that the convergence time can be significantly decreased by using an activity detector to exclude canceller coefficients below an appropriate minimum. In this paper, we present an activity detector design using a thresholding criterion based on the least squares technique, Akaike's information criterion (Homer et al. (1998) [2]) and Donoho's universal thresholding principle (Donoho (1995) [3]). This enables us to identify the significant crosstalkers within a DSL binder for each user. We further incorporate this strategy within the blind estimation NMMA and propose an enhanced crosstalk canceller. Our simulations indicate this multi-modulus detection-guided crosstalk canceller demonstrates improved convergence speed and has a steady state error close to that of the standard (non-detection-guided) canceller.     

微机械音叉陀螺的误差源研究􀀁

定性地讨论了微机械音叉特有的一些误差源。主要有机械结构的Ｂｒｏｗｉｎａｎ噪声,电路噪声,等。对上述误差源的认识是微结构制造和电路设计的基础。     

高速芯片封装中多平行传输线的设计与优化

随着封装基板朝着高阶高密度方向发展,其信号完整性问题也日趋严重。为研究高速互连结构中反射、串扰等问题与封装基板类型、设计参数和传输线物理特性的相关性,改进了简单的二线平行耦合模型,采用三维电磁仿真软件构建了新的封装级三平行传输线模型,分析了陶瓷基板与有机基板上的传输线反射和串扰特性,研究了该结构下减小反射系数与串扰噪声的方法。仿真结果表明,封装基板上传输线反射系数S11与阻抗匹配程度相关,受信号线宽、厚度和介质厚度影响较大,且S11最小值在不同频率下匹配的最优线宽也不同,需根据不同信号频率具体选择。近端串扰系数受边缘场作用,与线间距密切相关,远端串扰系数受介质厚度影响较大,在相同条件下,远端串扰噪声一般小于近端串扰,对其评估时需结合基板上信号密度、基板材料特性和介质厚度具体分析。     

Selected Crosstalk Avoidance Code for Reliable Network-on-Chip

With the shrink of the technology into nanometer scale, network-on-chip (NOC) has become a reasonable solution for connecting plenty of IP blocks on a single chip. But it suffers from both crosstalk effects and single event upset (SEU), especially crosstalk-induced delay, which may constrain the overall performance of NOC. In this paper, we introduce a reliable NOC design using a code with the capability of both crosstalk avoidance and single error correction. Such a code, named selected crosstalk avoidance code (SCAC) in our previous work, joins crosstalk avoidance code (CAC) and error correction code (ECC) together through codeword selection from an original CAC codeword set. It can handle possible error caused by either crosstalk effects or SEU. When designing a reliable NOC, data are encoded to SCAC codewords and can be transmitted rapidly and reliably across NOC. Experimental results show that the NOC design with SCAC achieves higher performance and is reliable to tolerate single errors. Compared with previous crosstalk avoidance methods, SCAC reduces wire overhead, power dissipation and the total delay. When SCAC is used in NOC, it can save 20% area overhead and reduce 49% power dissipation.     

一种基于模糊神经系统的图像去噪方法

提出一种对含有高斯噪声的数字图像的去噪方法,这种方法能够增强高斯噪声滤波器的性能,减少去噪对图像造成的模糊和失真。设计了一个模糊推理系统（FIS）,并利用ANFIS训练这个FIS。通过训练可以调整、优化FIS的内部参数值。训练图像数据由计算机程序自动生成。优化后的FIS即可处理输入的图像数据,产生增强的图像。从结果图像的视觉效果和量化标准两方面的实验和分析,可以看出这种方法可基本消除高斯噪声滤波器产生的模糊和失真,提高滤波器性能。实验表明模糊神经系统可以应用于图像去噪问题。在合理地选择隶属度函数、规则和训练数据的前提下,会产生明显的图像增强效果。     

A walsh-hadamard based distributed storage device for the associative search of information

A computer model for a distributed associative memory has been developed based on Walsh-Hadamard functions. In this memory device, the information storage is distributed over the entire memory medium and thereby lends itself to parallel comparison of the input with stored data. These inherent economic storage and parallel processing capabilities may be found effective especially in real-time processing of large amount of information. However, overlaying different pieces of data in the same memory medium creates the problem of interference or crosstalk between stored data and may lead to recognition errors. In this paper, a crosstalk reduction technique utilizing the gradient descent procedure is developed first. This minimizes the memory processing error and enhances memory saving. Second, for an efficient implementation of the memory structure, these associative memories are configured in a hierarchical structure which not only expands storage capacity but also utilizes the speed of tree search. Finally, a self-correcting technique is developed which achieves error-free recognition of near neighbors for any training pattern even among the presence of crosstalk.     

Sophisticated mobile robot sonar sensing with pseudo-random codes

Conventional time-of-flight sonar sensing is widely used within the autonomous mobile robot research community. One of its most severe problems is known as crosstalk. This paper presents experimental results of a new approach which allows one to operate a set of sonar sensors simultaneously. Nevertheless, frequent misreadings caused by crosstalk or external ultrasound sources are eliminated. This is achieved by carefully designing the emitted bursts, i.e. by using appropriate pseudo-random sequences together with a matched filter receiver well known from radar applications.