“信号与系统”课程逆Z变换的两个问题

Two Problems of Inverse Z-transform in Course of Signals and Systems

"信号与系统"课程是电子信息等多个专业的主干课程.文章探讨该课程中逆Z变换的两个问题,指出了教材中逆Z变换定义式关于围线C的不恰当描述并给出了正确描述;在高阶极点情况下,指出了部分分式展开法求逆Z变换的不便之处,补充了部分分式展开对应的系数计算公式.

＂Signals and Systems＂ is a significant primary course in electronics information and related majors.This article discusses two issues about Inverse Z-transform in the textbook,pointing out the inappropriate description of Contour C in the definition of Inverse Z-transform and giving an accurate one;pointing out the inconvenience of the partial fraction expansion method of Inverse Z-transform in the case of high-order pole,and deducing the coefficient formula of partial fraction expansion.