Signals and Systems
信号与系统是电气与电子信息类的核心理论课程，研究连续与离散信号的表示、变换与通过线性时不变系统的响应。课程内容包括信号的基本运算与分解、卷积积分与卷积和、连续时间傅里叶级数与变换、拉普拉斯变换、离散时间傅里叶变换与 Z 变换、系统函数与稳定性分析。本课程为通信、控制、图像处理与数字信号处理等后续课程提供关键数学工具与分析方法。
Signals and Systems is a core theoretical course for electrical and information engineering, studying the representation and transformation of continuous and discrete signals and their responses through linear time-invariant systems. Topics include signal operations, convolution, Fourier series and transform, Laplace transform, discrete-time Fourier transform, Z-transform, system function and stability analysis. It provides essential mathematical tools for communication, control, image processing, and digital signal processing.
学生录制一段不少于5秒的语音信号，叠加白噪声后，利用 MATLAB 计算其频谱并设计 FIR 低通与高通滤波器进行降噪处理。要求对比滤波前后信噪比，撰写报告说明滤波器阶数、截止频率选择依据及频域分析结果，提交代码、原始与处理后的音频文件。
Students record a speech signal of at least 5 seconds, add white noise, and use MATLAB to compute its spectrum and design FIR low-pass and high-pass filters for denoising. The report should compare signal-to-noise ratios before and after filtering, explain filter order, cutoff frequency selection, and frequency-domain analysis results. Submit code, original and processed audio files.