微弱信号相位检测的自适应陷波法及其应用  

Adaptive Wave Trap in Phase Detection for Weak Signal and Its Application

作　　者：李东[1] 蔡湘平[1] 

机构地区：[1]北京信息科技大学光电信息与通信工程学院,北京100192

出　　处：《自动化仪表》2012年第2期73-75,79,共4页Process Automation Instrumentation

基　　金：北京市自然科学基金资助项目(编号:KZ200811232018)

摘　　要：针对微弱信号因噪声影响造成剧烈的相位变化,采用常规的方法无法检测出其相位的现象,提出了一种自适应陷波方法。该方法采用自适应陷波算法来滤出期望信号,再对陷波后信号进行带宽压缩以提高信噪比,从而准确检测出信号的相位。根据检测方法,研制出以数字信号处理器为核心的检测系统,并应用此系统检测石英晶体输出的微弱信号的相位差。试验表明,对于信噪比小于-60 dB的微弱信号,系统相位检测精度达到2×10-6。Affected by noise,the phase of weak signal often changes fiercely and can／＇t be detected with conventional method,thus the method of adaptive wave trap（notching filtering） is proposed.By adopting adaptive wave trap algorithm,the expected signal is filtered out,and then the bandwidth of signal after wave trap is compressed to improve signal-to-noise ratio,and thus the phase of signal is detected accurately.The detection system with the digital signal as the core is developed in accordance with the detection method,and the phase difference of the weak signal output by quartz crystal is detected by this system.The experiment verifies that to the weak signal that SNR is less than-60dB,the phase detection accuracy of the system can reach 2×10-6.

关 键 词：自适应陷波 相位检测 信号处理 检测系统 石英晶体 FFT 

分 类 号：TP206[自动化与计算机技术—检测技术与自动化装置]