中文说明：[数字信号处理（第2版）][李力利,刘兴钊][电子教案和习题解答],内含ppt和课后习题答案。共九章，全面介绍了数字信号处理的理论知识，推导详细，课后题目答案很详尽
English Description：
[digital signal processing (2nd Edition)] [Li Lili, Liu xingzhao] [electronic teaching plan and exercise solutions], including PPT and after class exercise solutions. It consists of nine chapters, which comprehensively introduces the theoretical knowledge of digital signal processing. The derivation is detailed, and the answers to the questions after class are very detailed