“数字信号处理”课程教学方式改革

本文介绍如何将"数字信号处理"课程教学看作一个有机体,系统地安排其概念、用途、理论、方法、效率和实践等教学内容。教师应尽量顺应社会的需求和学生的特点,循序渐进,并按教学内容的进展配置相应的实例和趣味实验,提高学生的能动性。学生在学习多门课程的情况下,提高了本门课程的学习效率,学到"数字信号处理"的更多知识和培养创新的意识。     

“信号处理”课程的教学测评体系研究

本文介绍了国外大学对"信号处理"课程信号与系统概念测试集(SSCI)的研究,并采用该测试集对学生实施测试,通过分析测试结果准确把握学生对课程中基本概念的掌握情况,并反馈到教学实践中改进教学。SSCI测试还可以作为评价不同教师、教学方法和学校教学效果的客观量化依据,期待这类做法能推广到工科其它理论基础课程的教学中。     

基于Matlab的"数字信号处理"课程实验设计

本文设计了一个基于Matlab的"数字信号处理"课程综合性实验.该实验把"数字信号处理"课程中的许多离散的知识点串接了起来,包括采样、量化、滤波器设计、滤波器实现、DFT/FFT和滤波器的有限字长效应等.教学实践表明该实验有利于巩固学生课堂上学到的理论知识,提高学生的理论联系实际的能力和动手解决问题的能力.     

“数字信号处理”教学中易混淆的问题讨论

"数字信号处理"课程理论性和实践性比较强,概念比较抽象,学生感到难以理解和掌握.本文对"数字信号处理"教学中易混淆和易出错的知识点,如系统因果稳定性的判断、翻褶移位函数的实现及其Z变换、卷积与相关、四种傅里叶变换的关系、傅里叶变换的对称性以及高密度谱和高分辨率谱等部分,采用实例和对比讲解的方法,加上Matlab仿真,讨论了它们的实现及应用,以加深学生对概念的理解.     

“数字信号处理”课程课内配套实验的设计

本文构建和设计了基于Matlab的"数字信号处理"课程课内配套实验,并给出了构建课内配套实验应遵循的原则以及具体的实验设计。教学实践表明该配套实验可以加深学生对"数字信号处理"课程理论知识的理解,增强学生理论联系实际的能力和动手解决问题的能力。     

数字信号处理课程教学改革的探索与体会

针对"数字信号处理"课程实用性强、理论内容丰富但概念抽象难懂等特点,结合我校课程教学实际情况,从教学和实验两个环节进行了改革.在教学环节上精选教学内容、优化教学方法、丰富教学手段、突出概念的物理意义及应用、指导学生有针对性的做题;在实验过程改革考核机制,增加综合设计性实验,注重培养学生理论联系实际、独立分析解决问题的能力.实践表明教学改革取得了较好的效果.     

“信号与系统”和“数字信号处理”的优化教学

利用Matlab/Simulink软件优良的动态系统建模、仿真和分析特性,实现对整合的"信号与系统"和"数字信号处理"课程进行教学优化实践,使抽象的概念和原理可视化、形象化,不仅能保证学生在少学时下容易对知识的理解和掌握,更能加强理论和实践教学相结合,利于提高学生综合解决问题的能力.     

"数字信号处理"课程教学研究

为了帮助学生更便捷地学习"数字信号处理"课程,教师需要从前期材料搜集、中期授课、后期答疑等方面为学生做好服务工作.同时,学生应认真学习课程内容,多做习题,并虚心向教师请教.通过师生的共同努力,保证课程能顺利开展与完成.教师将思政元素悄然融入专业课程教学过程,此举为同类课程的教学研究提供有益借鉴.     

多采样率信号处理的发展

数字通信系统中,为适应传输、降低资源消耗、适于处理操作,常需要变换信号的采样率。多采样率信号处理理论从语音信号处理中发展起来,在应用中不断丰富。随着软件无线电的应用,多采样率变换在数字信号领域占据越来越重要的地位。多采样率信号处理技术与小波分析、分数阶傅里叶变换等其他信号处理技术相结合是未来发展的方向。     

关于提高“数字信号处理”课程授课质量的探讨

针对"数字信号处理"课程的公式多、抽象和难学等问题,结合我校课程教学实际情况,我们开展了如何激发学生学习兴趣、如何应用多媒体教学方式和如何把握好内容的前后呼应等方面的探索.该探索有机地将课程内容趣味性、多样化的教学模式和前后内容的关联性有机地结合在一起,取得了较好的效果.     

Interpolation and decimation of digital signals—A tutorial review

The concepts of digital signal processing are playing an increasingly important role in the area of multirate signal processing, i.e. signal processing algorithms that involve more than one sampling rate. In this paper we present a tutorial overview of multirate digital signal processing as applied to systems for decimation and interpolation. We first discuss a theoretical model for such systems (based on the sampling theorem) and then show how various structures can be derived to provide efficient implementations of these systems. Design techniques for the linear-time-invariant components of these systems (the digital filter) are discussed, and finally the ideas behind multistage implementations for increased efficiency are presented.     

分数阶傅里叶域两通道滤波器组

 基于两通道滤波器组构建的子带信号处理方法已在图像、语音信号处理中得到广泛的应用.本文从分数阶傅里叶域多抽样率信号处理基本理论和分数阶卷积定理出发,推导了分数阶傅里叶域两通道滤波器组准确重建的基本条件,并基于传统傅里叶域有限长标准正交镜像滤波器组和共轭正交镜像滤波器组的原型滤波器设计了分数阶傅里叶域标准正交镜像滤波器组和共轭正交镜像滤波器组.本文所提出的结论为分数阶傅里叶域滤波器组理论的建立提供了基本依据,同时也为分数阶傅里叶变换在图像、语音信号处理等工程实践中的应用奠定了理论基础.最后,仿真实验验证了所提分数阶傅里叶域滤波器设计方法的有效性.     

All-digital 2-channel parallel undersampling and reconstruction of band-limited signals

In this paper, we show that a band-limited signal can be reconstructed from two undersampled sequences of the signal, and further propose a 2-channel multirate undersampling and reconstruction method for band-limited signals. With such an approach, the sampling rate can be reduced to about one half of the Nyquist sampling rate. This method also has the advantage that no analog filters are needed to decompose the signal into two components with narrower bandwidths. Furthermore, the parallel processing of the two sampled sequences will lead to improved system performances. Finally, we consider the synchronization between the two sampled sequences, and show that the two A/D converters can be readily synchronized.     

MuDSPDEMO-demonstration package for multirate digital signalprocessing

This column describes an educational software package designed to support a graduate course on multirate digital signal processing. The program is implemented in MATLAB and uses a graphical user interface to integrate numeric computation and effective scientific visualization     

Synthesis of folded pipelined architectures for multirate DSPalgorithms

In this paper we formalize a novel multirate folding transformation which is a tool used to systematically synthesize control circuits for pipelined VLSI architectures which implement multirate algorithms. Although multirate algorithms contain decimators and expanders which change the effective sample rate of a discrete-time signal, multirate folding time-multiplexes the multirate algorithm to hardware in such a manner that the resulting synchronous architecture requires only a single-clock signal. Multirate folding equations are derived and these equations are used to address two related issues. The first issue is memory requirements in folded architectures. We derive expressions for the minimum number of registers required by a folded architecture which implements a multirate algorithm. The second issue is retiming. Based on the noble identities of multirate signal processing, we derive retiming for folding constraints which indicate how a multirate data-flow graph must be retimed for a given schedule to be feasible. The techniques introduced in this paper can be used to synthesize architectures for a wide variety of digital signal processing applications which are based on multirate algorithms, such as signal analysis and coding based on subband decompositions and wavelet transforms     

A CMOS 1.0-μm two-dimensional analog multirate system forreal-time image processing

Two-dimensional (2-D) filters for video signal processing typically operate at high uniform sampling rates and require very large delay-line (DL) memory blocks. By employing 2-D multirate signal processing techniques to reduce the sampling rate, not only the DL memory blocks can be downsized to save silicon area, but also the memory access time can be increased to save power as well. This is demonstrated in this paper considering a 2-D switched-capacitor multirate image processor that realizes (2×2)nd-order recursive low-pass and high-pass filtering functions employing half of the storage cells that would be needed in a nonmultirate system. Only one type of operational transconductance amplifier with 1-mS transconductance and 120-MHz unity gain bandwidth is needed for both the vertical filter and associated DL memory blocks and the horizontal decimating filter. Fully differential circuit techniques are employed to increase immunity to charge feedthrough injection in the analog storage cells. The complete system has been implemented in a CMOS 1.0-μm double-poly technology. The core active area is only 2.5×3.0 mm², and at 5-V supply and 18-MHz sampling it dissipates 85 mW     

Gröbner Bases and Multidimensional FIR Multirate Systems

The polyphase representation with respect to sampling lattices in multidimensional (M-D) multirate signal processing allows us to identify perfect reconstruction (PR) filter banks with unimodular Laurent polynomial matrices, and various problems in the design and analysis of invertible MD multirate systems can be algebraically formulated with the aid of this representation. While the resulting algebraic problems can be solved in one dimension (1-D) by the Euclidean Division Algorithm, we show that Gröbner bases offers an effective solution to them in the M-D case.     

Fast estimators of time delay and Doppler stretch based ondiscrete-time methods

Estimation of the time delay and the Doppler stretch of a signal is required in several signal processing applications, This paper is focused on the joint fine estimation of these two parameters by a fast interpolation of the estimated ambiguity function. Four discrete-time methods (viz. multirate, piecewise scaling, linear scaling, and indirect estimators), based on an orthogonal model, are introduced. Their mean square error is mathematically derived for random signals corrupted by additive random noises. The obtained expressions have been evaluated for some typical parameter sets in the reference case of Gaussian signals and noises. The numerical results, compared with the accuracy of a continuous-time estimator, show the near efficiency of the multirate estimator for a wide range of SNRs. In fact, the adjustable multirate estimator can operate under near optimal conditions, unlike the approximate (i.e., piecewise and linear) scaling and the indirect methods based on constant sampling rates     

信息专业"数字信号处理"的改革与实践

“数字信号处理”课程是信息专业一门重要的技术基础课．本文首先指出了课程改革的总体目标及具体思路,然后重点介绍了运用先进的计算机软件MATLAB来进行课程的教学改革步骤与实施过程．内容涉及课堂教学、实验、作业及考试等各个教学环节。实践证明,这种根据课程本身的特点运用MATLAB软件来进行课程全教学环节的改革具有自己的特色,取得了显著效果。