在研究自然现象和规律的科学研究和工程实践中，经常会遇到需要检测毫微伏量级信号的问题，如测定地震的波形和波速、材料分析时测量荧光光强、卫星信号的接收、红外探测以及生物电信号的测量等。这些问题都归结为噪声中微弱信号的检测。本课程运用电子学和信息论等学科知识，分析噪声产生的原因和规律，研究被测信号和噪声的统计特征及差别，分析电路中噪声和干扰的抑制方法，介绍和分析各种信号处理方法，以达到检测被背景噪声覆盖的微弱信号的目的。微弱信号检测技术通过利用信号与噪声不同的统计特征和规律使测量精度得到大幅度提高，也是发展新技术、探索及发现新规律的重要测量手段。研究噪声中微弱信号检测的原理和方法，是测量技术中的综合技术，运用这些原理合方法可以测量到传统方法不能测量的微弱量例如弱光、微位移、微振动、微温差、小电容、弱磁、弱声、微电导和微电流等。在物理、化学、生物医学、遥感和材料学等领域有广泛应用。本课程内容包括以下三个方面：1、电噪声的基础知识。主要介绍噪声及其统计特征、噪声源及电子元器件噪声模型、低噪声放大器的设计和电子电路中噪声和干扰的抑制方法等内容。2、典型微弱信号检测方法及仪器。主要介绍和分析相关检测原理及应用。3、微弱信号检测和处理方法。主要介绍维纳滤波、噪声抵消系统、自适应滤波、混沌中信号检测等噪声中信号恢复的基本理论和方法。同时简要介绍现代信号处理方法在微弱信号检测中的应用。

To detect the electric signal in nano-volt level and minimize noise pickup are frequent practice in scientific research and engineering. The detection and analyses of seismic signal, the measurement of the intensity of florescence when analyzing special materials, the receiving of the signals transmitted by satellites, the detection of infrared or bio-electrical signal and etc. are all instances of the application of low level signal detection technique. Based on electronics and information science, the graduate course Low-noise electronic Design，Detection of Signal in Noise will introduce intrinsic noise generation mechanism and the noise in active devices，provide a standard set of noise parameters that can be used to analyze noise in various devices. The course will also present the fundamentals of prevailing signal processing theories and methods, and will cover noise suppression and interference eliminating technique in the purpose of picking up and making measurement of low level signal from intensive background noise and interference. Many fundamentals of theories and technologies are involved in the practice of low-noise electronic design and detection of signal in noise. By making comprehensive use of distinct statistic characteristics of signal and noise, the low level signal detection technology is able to improve measurement resolution and accuracy greatly, and it is also a key measure to explore nature phenomenon, make discoveries and develop new technology. Low-level signal detection technology is widely used in physics, chemistry, biomedicine, remote sensing technique, material science and etc. By means of the concerned principle and method, many low level signals undetectable with traditional method, like weak florescence, nanometer-displacement, micro-vibration, small change of temperature for instance, can be measured. The contents of this course cover three aspects as follows,1.Fundamentals of electric noise and low noise electronic design. Mainly introduce the statistic characteristics of random noise, intrinsic noise sources, noise models, low noise preamplifier and its parameters design, the methods of elimination or really avoidance of electromagnetic interference.2.Typical low level signal detection method and instruments. Mainly analysis on the principles of correlation detection and its applications.3.Low level signal detection and processing methods. Mainly introduce the fundamentals of some prevailing signal processing methods for rehabilitating signal from noise such as Wiener filter, matching filter, adaptive filter,and signal detection in chaos. Some advanced signal processing methods and their application for low level signal detection is also briefly introduced.