On the design of two channel perfect construction QMF filters

This paper presents two rapidly convergent methods for the design of two‐channel odd degree linear phase FIR banks as well as IIR filter banks. In both cases, zeros of arbitrary multiplicity are assumed at z = −1, to ensure regularity of the generated wavelet basis. It is shown that in the FIR case, the problem reduces to the solution of an eigenvalue problem. A simple minimization method is proposed for its solution to reduce most of the computational complexities of eigenvalue evaluations. In the IIR case, a simple rapidly convergent algorithm is also described for the determination of a perfect as well as pseudo‐perfect reconstruction stable IIR function having equiripple pass and stop band responses and with almost constant group delay. It is also shown that the analysis and synthesis banks are of same complexities, and as a result of being expressed as sum of two all‐pass functions, they are realized in a lattice form. Therefore, they are immune from quantization effects. Illustrative examples are also given. Copyright © 2000 John Wiley & Sons, Ltd.     

Signal separation using second‐ and high‐order statistics

This paper presents two methods for signal separation. In either method, the fundamental criterion for separation relies on reducing to zero, or at least minimizing, the output cross‐correlation or cross‐cumulant functions of a decoupling multi‐input–multi‐output system that is fed with mixed signals. In one of the approaches used, the parameters of this system are determined through solving — in a least‐squares sense — a linearized set of equations describing the deviations from zero of either the cross‐correlation or cross‐cumulant functions when evaluated for different lags. An alternative rapidly convergent adaptive algorithm is also described for minimizing the cross‐correlation or cross‐cumulant functions. The paper also considers both FIR and IIR representations of the decoupling system. It shows that using IIR functions in the decoupling system does not offer any merit over the FIR case. Illustrative examples are given to show the performance of the proposed algorithms. Copyright © 2000 John Wiley & Sons, Ltd.     

高压巡线机器人电磁导航系统研究与设计

为提高架空高压线路故障检测效率,研究并实现了高压巡线机器人自主巡检作业新方法,即巡线机器人在PC104硬件系统和嵌入式软件系统平台上分析处理输电线图像数据对其进行故障检测。基于电磁检测的导航系统由横竖两方向多方位的电磁传感器阵列组成;PC104采用相对值检测方法,根据高压输电线路周围磁场的感应电压跟半径的反比例关系原理,比较传感器阵列输出的系列模拟电压值来判断机器人相对输电线路的姿势并识别线上障碍;针对电磁导航系统信号特点,研究MATLAB数字滤波器优化设计方法;设计出IIR滤波器对经过放大的信号进行处理,研究并实现了PC104的IIR优化算法。仿真结果和现场试验证明,基于IIR滤波的巡线机器人电磁导航系统结构简单、效果显著。     

IIR陷波滤波器设计

从实际应用的要求出发，以IIR数字滤波器的基本理论为依据，按照层次化、模块化、参数化的设计思路，采用VHDL硬件描述语言和原理图两种设计技术进行了IIR陷波滤波器的硬件设计，并在制作的实验电路中进行了实际滤波效果测试，测试结果表明该IIR陷波滤波器具有很好的滤波效果，验证了设计的正确性。     

Design of IIR multiple notch filters

A new method for designing IIR multiple notch filters is presented, which satisfies the notch frequency specifications exactly and realizes 3 dB rejection bandwidths which are lower than those specified. An allpass filter-based realization has been worked out to make the design relatively insensitive to coefficient inaccuracies. Illustrative examples are given. © 1998 John Wiley & Sons, Ltd.     

An adaptive recursive filter for autoregressive inputs

A novel off-line procedure for IIR system identification problems has been recently proposed and analysed under the assumption of a white input signal. The method happens to have a single, unbiased stationary point under this condition. This approach is based in interpolation theory and tries to overcome the drawbacks of equation- and output-error strategies. Here it is shown that the unicity of the stationary point is still preserved for a wider class of input signals, namely autoregressive processes of a certain order. With coloured input signals, an SPR condition arises for the convergence of the original on-line algorithm. A modification is proposed that eliminates this SPR condition, while leaving the stationary point untouched. Two different structures that implement the on-line algorithm are presented; the use of a lattice structure for the implementation of the recursive part of the filter is considered as well. © 1998 John Wiley & Sons, Ltd.     

基于克隆选择算法的IIR数字滤波器优化设计

鉴于IIR数字滤波器设计本质上是一个多参数非线性复杂函数优化问题,提出应用具有全局搜索能力强,收敛速度快特点的克隆选择算法优化IIR数字滤波器的相关参数,进而形成一种新的IIR数字滤波器优化设计方法。给出了IIR滤波器优化设计的数学模型,描述了应用克隆选择算法优化设计IIR数字滤波器的具体实现步骤,并通过低通和高通IIR数字滤波器设计的仿真结果表明该方法的有效性和高效性。     

The modified Pascal polynomial approximation and filter design method

Polynomial approximations are extensively used in analog and IIR digital filter design. In this paper, a comprehensive filter design and an optimization procedure are presented explicitly using a filter‐appropriate modified Pascal polynomial. The so‐designed all‐pole Pascal filters exhibit non‐equiripple passband and monotonic transition and stopband responses. The order of the new Pascal filters is calculated from the order inequality which, although it cannot be analytically solved, leads to a nomograph that has been created and is presented here. Inevitably, the mathematical complexity introduced by the nature of the Pascal polynomials makes the analytical expression of the poles of the transfer function unfeasible and for that reason poles are given by means of appropriate tables. The design method is demonstrated in several detailed examples and Pascal filters are compared with their all‐pole counterparts, Butterworth and Chebyshev, over which they reveal certain advantages and disadvantages. Copyright © 2010 John Wiley & Sons, Ltd.     

A recursive least squares algorithm for an orthogonal iir adaptive line enhancer

A novel method is described for the frequency estimation of signals from a noisy background. It is based on realizing the IIR adaptive filter as a parallel connection of discrete orthogonal sections. A fast Gauss-Newton-type recursive algorithm has also been derived to update the parameters of these orthogonal sections. It has been shown that for highly noisy signals, this approach significantly improves the frequency estimation capabilities as well as increases the overall signal-to-noise ratio of the adaptive recursive filters. Illustrative examples are given to verify these results.     

Current‐mode filters based on current mirror arrays

A technique is proposed for obtaining current‐mode filters based on current mirror arrays that operate as unity gain current amplifiers. These amplifiers by properly driving capacitors realize active lossless integrators which are the basic active elements for the derivation of filters according to the leapfrog method. Due to the fact that both the structure of the amplifiers and the adapted method for filter design are simple, the proposed technique is attractive for filter design and implementation. A design and the implementation of two third‐order low‐pass filters are presented. The array of the amplifiers has been implemented in a 0.8 µm CMOS technology. Copyright © 2007 John Wiley & Sons, Ltd.     

On the optimum design of symmetric two-dimensional IIR digital filters with coefficients of finite word length

A method is described for the design of octagonally symmetric, non-symmetric half plane, two-dimensional IIR digital filters with integer coefficients. The design problem is formulated as an integer non-linear problem and the solution is achieved via an integer non-linear optimization algorithm. An example illustrates the features of the proposed approach.     

Ultrahigh-speed long-distance TDM and WDM soliton transmissiontechnologies

Recent progress on time-division multiplexed (TDM) and wavelength-division multiplexed (WDM) soliton transmission is described, in which dispersion management (DM) plays an important role in increasing the power margin and the dispersion tolerance. The characteristics of the DM soliton are compared with those of return-to-zero (RZ) and nonreturn-to-zero (NRZ) pulses. With a small dispersion swing, the system can still be described as an average soliton with a nonlinear Schrodinger equation (NLSE), whereas with a large dispersion swing, the soliton-like steady-state pulse becomes a chirped Gaussian pulse, in which the master equation is closer to a linear Schrodinger equation (LSE) with a parabolic potential well. An in-line modulation scheme up to 80 Gb/s per channel and its two-channel WDM transmission over 10000 km are described. A 640-Gb/s (40 Gb/s×16 channels) WDM soliton transmission over 1000 km is also reported with a DM single-mode fiber, without the use of in-line modulation. Finally, dark soliton transmission at 10 Gb/s over 1000 km is described as a different nonlinear pulse application     

基于机会约束规划的输电系统规划方法

输电系统在电力市场中扮演着十分重要的角色,因为其提供了实现公平竞争的场所.输电系统的状况如容量充裕性对电力市场的竞争性有重要的影响.适当地扩展或加强输电系统对满足发电公司和用户的需要、消除或减缓输电系统阻塞具有重要作用.与传统的输电系统规划问题相比,电力市场环境下的输电系统规划更加复杂,需要处理的不确定性因素更多.机会约束规划是专门用于解决包含不确定性因素的优化问题的一类随机优化方法,适用于市场环境下的输电系统规划问题.文中将机会约束规划引入到市场环境下的输电系统规划研究中,给出了基于蒙特卡罗仿真和遗传算法的求解方法,为解决这一重要而困难的问题做了一些新的尝试,并通过一个算例系统说明了该方法的可行性.     

On IIR‐based bit‐stream multipliers

We analyze the existing bi‐level IIR‐based bit‐stream multiplier and propose selection criteria for the key design parameter governing droop and phase linearity. Based on the proposed choice of parameter, we then extend the bi‐level design to tri‐ and quad‐level architectures that offer better signal‐to‐noise performance. Hardware complexity and noise performance of these designs are also contrasted with previously proposed FIR‐based bit‐stream multipliers. Useful design guidelines are subsequently drawn. Copyright © 2010 John Wiley & Sons, Ltd.     

Design of Sinh‐Domain filters using complementary operators

A new systematic method for designing Sinh‐Domain filters is introduced in this paper. This is achieved by employing an appropriate set of complementary operators, in order to transpose the conventional functional block diagram representation of each linear operation to the corresponding one into the Sinh‐Domain. The proposed method offers the benefits of facilitating the design procedure of high‐order Sinh‐Domain filters and of the absence of any restriction concerning the type and/or the order of the realized filter function. As an example, a third‐order Sinh‐Domain leapfrog filter is designed by employing the proposed set of operators. Two possible realizations are given and their performance has been evaluated and compared through simulation results. Copyright © 2011 John Wiley & Sons, Ltd.     

On the design of 1D IIR digital filters with coefficients of finite word length

This paper presents new linear programming techniques for the design of optimal 1D IIR digital filters. the first method is based on a linear minimax criterion and leads to a linear programming approximation problem whose optimal solution is attained by a new fast algorithm. Next, the linear minimax approximation problem is extended and formulated as two linear integer programming problems which permit the design of 1D IIR digital filters with coefficients of finite word length. the first of these methods is formulated as a 0-1 integer linear programming problem and its optimal solution is attained rapidly by a new algorithm. This method appears to be suitable for the design of high-order digital filters. the second method is more general and is formulated as a mixed integer linear programming problem. to solve the design problem efficiently, a new integer tree search algorithm is introduced. the feasibility of the proposed algorithms is illustrated with detailed solutions or numerical examples.     

On orthogonal realizations for adaptive IIR filters

Convergence speed is one of the main concerns in adaptive IIR filters. Fast convergence can be closely related to adaptive filter realization. However, with the exception of the lattice realization that is based on the nice properties of Szëgo orthonormal polynomials, no other adaptive IIR filter realization using orthonormal characteristics seems to be extensively studied in the literature. Furthermore, many orthogonal realizations for adaptive FIR filters, that are particularly suitable for rational modelling, have been proposed in the past years. Since rational orthogonal basis functions are a powerful tool for efficient system representation they seem attractive for adaptive IIR filters. In this paper, we present some theoretical results related to the properties of a generalized orthonormal realization when used for mean‐square output error minimization in a system identification application. One result is related to the low computational complexity of the updating gradient algorithm when some properties of the orthonormal realization are used. An additional result establishes conditions for the stationary points of the proposed updating algorithm. In order to confirm the expected performance of the new realization, some simulations and comparisons with competing realizations in terms of computational complexity and convergence speed are presented. Copyright © 2000 John Wiley & Sons, Ltd.     

考虑双通道随机时延的区域互联电网AGC方法

在区域互联电网网络化自动发电控制(Automatic Generation Control,AGC)过程中,信息传输在双通道(如控制器到执行器(C-A)、传感器到控制器(S-C))均存在时延问题。基于模型预测控制(MPC)技术,拟利用其预测特征,通过控制过程中信息的存储与处理,消除双通道随机时延对控制效果的负面影响。首先,在考虑双通道时延的前提下,构建互联电网AGC系统模型,并就时延的存在对控制效果的影响进行了分析。然后,针对互联电网AGC系统的控制模式对集中式MPC(CMPC)的实现方法进行了讨论,分析了在CMPC框架下双通道时延的处理方法。在此基础上,分别以阶跃与随机负荷曲线为扰动变量,获取互联电网频率及区域控制偏差曲线。仿真结果表明在考虑互联电网AGC系统双通道随机时延的情况下,所提方法能够保证系统良好的动态响应性能,从而验证了其可行性和有效性。     

一类椭圆数字滤波器的全新设计方法

在各种滤波器中，椭圆滤波器具有其独特的优点，但设计过程相当繁杂，本文针对半带ＩＩＲ椭圆滤波器设计方法，提出对椭圆函数实施一种变换，使其能与契比雪夫多项式的某些性质相结合，得出一种极其简便的全新设计方法，其优点是初始值数据较少，设计步骤简练，计算量仅约为文献〔１〕的１／４，而精度与其相同。     

用基于全通滤波器的ⅡR陷波器抑制工频通信中的谐波干扰

针对双向工频通信的信号特征，为了解决IIR陷波滤波器系数在低频段敏感度高的问题，提出采用基于全通滤波器的IIR陷波滤波器来消除电网谐波干扰的新方法。该陷波器可以由格型运算结构来实现，并因为全通滤波器的分子与分母之间的镜像对称关系，使滤波器在低频段具有非常低的系数敏感度。该文详细论述了该陷波滤波器的基本原理和设计方法，并通过一个设计实例说明了该方式由于量化效应引起的频率偏移量要远远小于级联方式。现场实验与仿真都证明了该滤波器能够非常有效地抑制电网中的基波和3、5次谐波，大大提高了对双向工频通信信号的检测能力。