摘要
如何检测埋藏于噪声背景下的微弱信号一直是信号测量领域的关键技术,而采用互相关函数的方法可以很好地对微弱信号进行检测,其主要由信号通道、参考信号通道和相关器3部分组成。采用单片机产生正弦波作为参考信号,控制频率与相位,具有频率/相位自适应的功能,解决了调试参考信号过于繁杂的问题。利用相关器对两个信号之间的相位进行检波,得到输出的结果与待测信号的幅值成线性关系。对于锁频锁相产生的跟踪误差,采取了类似于取样积分的算法对其进行处理,很大程度上消除了误差。最后所得的输出结果基本呈线性,效果令人满意。
How to detect the signal hiding in noise is an important problem. This article is mainly talking about how to make a weak signal detection instrument based on cross-correlation function method. The detector consists of three parts, which are the signal channel, the reference signal channel and cross-correlatio detector. The reference signal channel is used to generate a reference signal, using MCU to generate a PWM, which can control the frequency and phase. It＇s easy to control the reference signal. Cross-correlatio detector is used to detect the phase between the two signals, which is mainly composed of multiplier. It uses the method like sample integral method. The final output results show linear, which is satisfactory.
出处
《微型机与应用》
2013年第9期14-17,共4页
Microcomputer & Its Applications
关键词
微弱信号测量
相关器
乘法器
滤波
相敏检波
weak signal measurement
cross-correlatio detector
multiplier
filtering
phase sensitive detector
