摘要
基于FFT的载波捕获方法对高动态信号不能适用,离散匹配傅里叶变换(DMFT)虽可用于高动态信号,但是其运算量大、精确度差。基于以上分析本文提出了将延迟自相关、FFT与DMFT三者相结合的二维载波捕获算法。首先将中频采样信号与其延迟做自相关,通过信号的延迟自相关的FFT得到频率变化率的粗略估计值,进而得到起始频偏的粗略估计值,然后在所得值附近利用DMFT进行搜索,从而获得高精度的参数估计值。此方法缩小了搜索的范围,在运算量减少的同时,也提高了参数的估计精度。仿真结果证明本文提出的方法有效可行。
The high dynamic carrier capture based on fast Fourier transform （FFT） is not applicable. Discrete match Fourier transform （DMFT） can be used in high dynamic signal. But it has poor precision and large calculation. A two-dimensional carrier capture algorithm is proposed based on the above analysis with the three combination of FFT, self-correlation and DMFT. Firstly, if-sampled signal and its delay make self-correlation, then the frequency variation rough estimate is abtained through FFT on the delay self-correlation, and the rough estimation of the initial frequency shift is obtained. After that, searching near the income value in DMFT obtain the high-precision parameter estimation. The method narrows the searching scope, reduces computation and improves the precision of estimation. The simulation results prove that the method is effective and feasible.
出处
《数据采集与处理》
CSCD
北大核心
2011年第4期490-493,共4页
Journal of Data Acquisition and Processing
