摘要
针对铁路行车安全对轨道电路移频信号检测精度的要求及测试仪表对实时性的要求,分别研究了以快速傅里叶变换(FFT)与线性调频Z变换(CZT)算法为基础的频谱校正方法;采用频谱校正方法,将FFT和CZT变换中存在的频谱泄漏还原为接近无泄漏状态,实现信号参数的准确获取;再从算法原理、误差和运算复杂度等3个方面进行对比性分析,结果表明:对于国内18信息移频信号,在中心频率、低频和频偏的标准值处,使用两种算法得到的各参数计算值的绝对误差分别满足0.2Hz、0.02Hz和0.2Hz;各参数标准值发生一定偏差时,FFT的频谱校正算法的参数检测效果优于CZT的;FFT的复数乘法运算量较小。
For the safety of the railway,the accuracy requirement of track circuit frequency-shift signaling detection and real-time requirement of test instrument,the methods of spectral correction based on the algorithm of Fast Fourier Transform（FFT） and Chirp-Z Transform（CZT） were researched.It makes the spectral leakage revert approximately by the method of spectrum correction,thus making signal parameter received exactly.Then make a comparative analysis through algorithm,error and computational complexity.Firstly,the calculated parameters＇ absolute error which are obtained using the two algorithms respectively meet 0.2Hz,0.02Hz and 0.2Hz at the standard values of center frequency,low frequency and frequency deviation for Domestic 18 kinds of Information Frequency-shift Signal.Secondly,when the standard values of parameters have a certain deviation,the parameter detection effect of FFT spectrum correction algorithm is better than CZT＇s.At last,the FFT has a smaller complex multiplication computational cost.
出处
《计算机测量与控制》
CSCD
北大核心
2012年第2期414-417,共4页
Computer Measurement &Control
关键词
移频信号
FFT
CZT
频谱校正
对比
frequency-shift signaling
FFT
CZT
spectrum correction
comparison
