时域，频域，s域和z域,一些网上的总结

https://www.jianshu.com/p/29f4a7663b14

https://wenku.baidu.com/view/26961183b9d528ea81c779e0.html

https://www.zhihu.com/question/22085329

https://wenku.baidu.com/view/92e35c870408763231126edb6f1aff00bed570cc.html

*****

另外北大何同学出的书确实很好的说。。https://blog.csdn.net/luoganttcc/article/details/77848509