信号与系统分析中直流信号的特殊性探究  

Discussion about Particularity of DC Signal in Signal and System Analysis

作　　者：任蕾[1] 薄华[1] 金欣磊[1] REN Lei;BO Hua;JIN Xin-lei(College of Information Engineering,Shanghai Maritime University,Shanghai 201306,China)

机构地区：[1]上海海事大学信息工程学院

出　　处：《电脑知识与技术》2019年第7X期259-261,共3页Computer Knowledge and Technology

基　　金：上海海事大学2016-2018三年规划教材项目资助

摘　　要：信号分解是线性时不变系统分析的理论基础之一。包含直流信号的一般信号可分解为直流信号与某因果信号之和的形式,且此类信号是时间无限信号。针对连续直流信号,由于其微分后的积分运算无法恢复原信号,因此在应用卷积微积分性质、傅里叶变换时域积分性质、拉普拉斯变换时域积分性质时,需特别注意直流信号的特殊性,不能直接使用上述性质。同理,针对离散直流信号,在应用卷积和的差分求和性质、离散傅里叶变换的时域求和性质时,同样需注意直流信号的特殊性。本文总结了直流信号的各类基本特性,以及在各类应用中的特殊方法,并给出实例说明如何应用上述性质。Signal decomposition is one of the theoretical fundamentals in time-invariant system analysis.Signal which contain DC signal can be decomposed into DC signal and causal signal.And,the signal is time infinite signal.When the differential or difference of DC signal is integrated or summed,the result is not the original signal.Therefore this results in particularity for continuous DC signal when differential and integration property of convolution,time-domain integration property of Fourier transform and time-domain integration property of Laplace transform are applied.It is same for discrete DC signal when applying difference and summation property of convolution,as well as time-domain summation property of DTFT.Those mentioned properties cannot be directly used for DC signal.Several basic properties of DC signal are summarized and examples are given to demonstrate how to apply them.

关 键 词：直流信号 卷积的微积分性质 傅里叶变换的时域积分性质 拉普拉斯变换的时域积分性质 卷积和的差分求和性质 离散时间傅里叶变换的时域求和性质 信号与系统 

分 类 号：TN911[电子电信—通信与信息系统]