Efficient multiple path propagating tests for delay faults

This paper presents a test generation procedure for obtainingmaximal multiple-path-propagating robust tests, which detect the largest possible number of path faults simultaneously. Specialized heuristics are used to facilitate the generation of such tests in two-level circuits, and methods are given for extensions to multi-level circuits. Experimental results are presented to demonstrate the efficacy of this approach, which is seen to significantly reduce test-set lengths for path delay faults by generating highlyefficient robust tests. Limitations of the method are discussed, together with suggestions for future research.     

DC-DC变换器的大信号建模及鲁棒控制方法

本文从工程实践的要求出发,将建模和控制器的设计紧密结合,提出了一种新型DC-DC变换器大信号建模方法,基于这一模型,将线性时变不确定系统的鲁棒控制方法应用于DC-DC变换器的控制器设计.本文所提出的建模和控制器设计方法适用于全部四种基本PWM型DC-DC变换器.计算机仿真和实验证明,本文设计的控制器对输入电源电压扰动和线性负载电阻扰动具有良好的鲁棒性,且实现方案简单易行.     

离散马尔可夫跳跃系统的鲁棒H∞滤波

研究了离散时滞不确定马尔可夫跳跃系统的鲁棒H_∞滤波器设计,其中系统的参数为范数有界不确定且时滞相关。基于李雅普诺夫函数的方法和引入附加矩阵,得到新的稳定条件,具有较小的保守性。根据得到的稳定条件,通过求解LMI得到滤波器参数,并最终通过数据示例验证方法的可行性。     

区间矩阵的Hurwitz与Schur鲁棒稳定性检验

提出基于二维面检验的区间矩阵Ｈｕｒｗｉｔｚ与Ｓｃｈｕｒ鲁棒稳定的充分必要条件。证明区间矩阵的Ｈｕｒｗｉｔｚ与Ｓｃｈｕｒ鲁棒稳定性可由其二维表面的稳定性保证。为证明本文区间矩阵的鲁棒稳定性检验的可应用性，给出了实例。     

Parity bit calculation and test signal compaction for BIST applications

Parity bit checking and pseudo-exhaustive testing are two design techniques which have been widely discussed in the BIST literature but have seldom been employed in practice because of the exponential nature of the processes involved. In this paper we describe several procedures designed to avoid these exponential explosions. Specifically we show how the parity of a large combinational function can (often) be quickly calculated. This is accomplished by an examination of the circuit realization itself particularly with regard to the connectivity between the various inputs and outputs. We then show how this same approach can be used to partition circuits so that they can be tested efficiently with a relatively small number of test patterns. Using these methods we were able to calculate the parity bits for more than 80% of ISCAS benchmark circuits' outputs. Interestingly enough, only 15% of these outputs were found to be parity-odd, but for these cases high fault coverage was invariably found to result. Several examples are included.This work was partially supported by the National Science Foundation under grant MIP-8902014.     

一类2-D奇异系统的鲁棒稳定性分析

针对一类不确定2-D奇异系统第二类Fornasini-Marchesini(SFM-Ⅱ)模型,在闭环系统边界相容,且无跳跃模的条件下,基于Lyapunov稳定性分析方法,利用线性矩阵不等式(LMI)得到具有不确定参数的二维SFM-Ⅱ系统鲁棒稳定性充分条件,并给出了不确定系统的静态状态反馈控制律,为2-D奇异系统的分析与设计提供了一条有效途径。     

Rateless codes with adaptive parity allocation for satellite systems

In this paper, we propose efficient parity allocation schemes when rateless codes are used in satellite communication systems in conjunction with an adaptive coding and modulation (ACM) scheme. ACM schemes are widely used in modern satellite communication systems to maintain the required error rate performance under channel impairment (such as rain fading observed in high‐frequency bands). The performance enhancement of ACM can be achieved by providing a good channel prediction and mode allocation method. In the case of a channel prediction or allocation error, rateless codes can be used as an effective means of retransmission to compensate for the performance degradation. After investigating the performance behaviour of rateless codes combined with ACM, we derive a mathematical formula to find the optimum parity length of the rateless code to be retransmitted to satisfy the target performance requirements. Simulation results described in this paper show that the proposed method can be used to enhance the error performance as well as spectral efficiency.     

动态数据的稳健处理

本文研究了对于含有异常值的动态数据如何进行参数估计及建模的问题．详细论述了异常值的识别、检测与剔除，进而提出了一种在微机上实现稳健回归的野点剔除迭代算法，这对于建立性能优良稳定的参数模型具有广泛的实用价值。     

一种适用于分集MIMO雷达鲁棒的有源假目标鉴别方法

分集多输入多输出(MIMO)雷达在对抗欺骗式假目标干扰方面有着体制优势,已有文献在假设真实目标回波完全去相关的假设下,通过对目标慢时间复包络序列进行相关性检验来鉴别假目标。考虑到在真实目标回波不完全去相关条件下此有源假目标鉴别方法性能下降较严重,提出了一种鲁棒的有源假目标鉴别方法。仿真分析表明,在真实目标回波存在相关性的场景下,此方法有着较明显的性能优势。     

Robust Non-Fragile Guaranteed Cost Control for Nonlinear Time Delay Discrete-Time Systems Based on T-S Model

This paper concerns the robust non-fragile guaranteed cost control for nonlinear time delay discrete-time systems based on Takagi-Sugeno （T-S） model. The problem is to design a guaranteed cost state feedback controller which can tolerate uncertainties from both models and gain variation. Sufficient conditions for the existence of such controller are given based on the linear matrix inequality （LMI） approach combined with Lyapunov method and inequality technique. A numerical example is given to illustrate the feasibility and effectiveness of our result.     

弹性体导弹鲁棒控制器设计

基于欧拉-自由梁模型理论得出弹性体导弹横向振动模型,用模态分析方法对模型进行求解。结合弹性导弹的刚体运动方程,得到包括横向振动和刚体运动的增广模型,对该模型进行鲁棒控制器设计,仿真结果表明,所设计的鲁棒控制器能够在保证弹体运动姿态控制的同时抑制横向振动。     

用于自适应天线的稳健的RLS算法

抗干扰通信是电子战的重要组成部分，自适应天线不仅具有很强的抗干扰能力而且可以与其它通信抗干扰技术相兼容，自适应算法是自适应天线的核心。本文把应用数学学科研究的热门方法之一“稳健估计（RE）”应用于RLS算法中，得到稳健的RLS算法（RRLS），理论分析与计算机模拟结果都证明了RRLS算法基本保持了RLS算法的优点，同时在抗突出值干扰方面，优于RLS算法，提高了RLS算法的稳健性。     

协同系统鲁棒波束成形算法研究

由于实际很难获得理想信道状态信息(CSI),传统协同波束成形算法性能严重下降。设计对信道误差具有鲁棒性的波束成形算法具有重要的实际意义。针对放大转发协同系统最大化目的节点信噪比(SNR)准则下的波束成形设计,提出对应鲁棒算法。该算法从最坏情况鲁棒设计思想出发,建立保证鲁棒性的最优化问题,应用扩展S引理和Schur补定理将该问题由初始不可解转化为可解的准凸问题,进而求解出保证鲁棒性的波束成形因子。仿真表明:同等CSI偏差下,所提鲁棒算法的中断概率性能优于传统波束成形算法。     

鲁棒约束恒模自适应波束形成算法

线性约束恒模算法能够有效克服恒模算法中存在的干扰捕获问题,但在信号方向向量存在偏差的情况下,其性能将会受到影响.针对上述问题,本文提出了鲁棒约束恒模自适应算法并对其性能进行了分析.该算法收敛速度快,抗扰动性强,对信号方向向量的偏差具有较强的鲁棒性,改善了系统的输出信干噪比.仿真实验表明,与线性约束恒模算法相比,鲁棒约束恒模算法具有很好的性能.     

多时滞Cohen-Grossberg神经网络鲁棒稳定性的新判据

分析了一类具有多时滞及参数摄动的Cohen-Grossberg神经网络的全局鲁棒稳定性.通过构造适当的Lyapunov泛函,以线性矩阵不等式形式给出了平衡点全局鲁棒稳定的判据.此外,所有结论的建立都不需要假定互连矩阵的对称性及激活函数的可微性和单调性.仿真结果进一步证明了结论的有效性.     

认知中继网络中的鲁棒传输

In cognitive relay networks, the transmission of Secondary Users (SUs) suffers from the activity of Primary Users (PUs) and wireless channel fading. Therefore, how to achieve robust transmission for cognitive relay networks is a challenging task. In this paper, we propose a relaying transmission scheme which exploits robust beamforming at the physical layer and rateless codes at higher layers. We derive the optimal beamforming weight vector and analyze the performance of the proposed scheme when the channel estimation is not accurate between two SU nodes. We also study how the amount of channel information between SU and PU impacts the system performance. Simulation results validate our theoretical analysis and demonstrate that the proposed scheme can significantly enhance the system throughput.     

Designs and architectures of filter bank trees for spectrally efficient multi-user communications: review, modifications and extensions of wavelet packet filter bank trees

A review is presented first of the evolution of transmultiplexers since about 1966, in the context of a long progression of theoretical advances and developments leading to recent proposals to fundamentally improve OFDM type systems using principles of perfect reconstruction filter (PRF) banks. The equivalence of transmultiplexers to OFDM type multi-user systems is discussed. The desirable goals for performance and implementation of transmultiplexers or multiband, multiuser communication systems that are addressed and met in this paper using filter bank trees are set down. Then modifications and extensions are presented of the designs and architectures of wavelet packet based synthesis and analysis pairs of filter bank trees (Sablatash and Lodge in Digital Signal Process 13: 58–92, 2003) that can be used as transmultiplexers. These exhibit a number of advantages over the previous designs and address three shortcomings of the designs used to illustrate basic principles in Sablatash and Lodge (Digital Signal Process 13:58–92, 2003). The first of these is the asymmetry of the magnitude frequency responses of the multiplexer channels, which is addressed using a symmetric design for a lowpass and highpass quadrature mirror filter (QMF) pair described herein. The second is the problem of minimizing the total delay of the signal in passing through the analysis and synthesis filter banks. This is addressed using an architecture involving DFT polyphase synthesis filter banks to replace the wideband VSB filters at the roots of the two identical synthesis filter bank trees, but results in the multiplexer having fewer levels. In this way a tradeoff is effected of lower delay and complexity with fewer levels of bandwidth on demand. At the receiver matching DFT polyphase analysis filters and the other matching analysis filters are implemented. The third shortcoming is the difficulty in designing a synchronization scheme if the filters in the synthesis and analysis filter banks have non-linear phase. This is addressed by designing linear phase filters that do not affect the ISI to any significant degree for communication purposes, although exact perfect reconstruction is lost, but greatly ease and improve the design of the synchronization scheme. Relationships of this paper and its advantages over recent research studies and IEEE 802.22 standards proposals using PR filter banks for multi-user systems to greatly improve on OFDM systems are discussed. Financial support under Industry Canada’s Spectrum Research Funding is gratefully acknowledged.     

基于协作多点下行传输的非线性鲁棒预编码

对于协作多点系统,下行信道信息误差会大幅降低联合传输的性能。为了避免下行信道信息误差对联合传输的影响,本文利用其二阶统计特性,设计了非线性鲁棒预编码算法。由于协作多点系统的特点和非线性鲁棒预编码的结构会导致用户间的性能差异,本文通过优化非线性鲁棒预编码算法的连续干扰消除先后顺序,从而改善性能最差用户的误码率,降低非线性鲁棒预编码算法的平均误码率。仿真结果表明当下行信道信息误差存在时,本文所提出的非线性鲁棒预编码性能优于传统的线性和非线性预编码性能。仿真结果还表明优化排序能提高非线性鲁棒预编码的性能增益。     

考虑压电陶瓷不确定性的鲁棒自适应控制

选择信息熵作为判定相似性的工具,在判定数据相似性的基础上选择控制对象等效模型参数。采用简单的一阶惯性模型等效复杂的压电陶瓷模型。考虑实际压电器件的不确定性,在等效模型中,将不确定性视为符合高斯分布的变量。考虑不确定参数的影响,基于线性矩阵不等式(LMI)法的鲁棒镇定,保证系统的鲁棒稳定性。选定控制目标,使用自适应李雅普诺夫(Lyapunov)函数方法设计模型控制器。仿真结果验证控制策略效果良好。     

Multiple-output parity bit signature for exhaustive testing

In this article we propose a multiple-output parity bit signature generation method for exhaustive testing of VLSI circuits. Given a multiple-output combinational circuit, a parity bit signature is generated by first EXORing all the outputs to produce a new output function and then feeding this resulting function to a single-output parity bit signature generator. The method preserves all the desirable properties of the conventional single-output circuits response analyzers and can be readily implemented using the current VLSI technology.