伽利略搜救信号FOA估计算法

在GALILEO/SAR系统中,FOA参数的估计精度直接决定着系统的定位精度。对GALILEO/SAR信号的特点进行了分析,在对FFT方法进行阐述的基础上,对Rife和相位差校正法2种频率估计算法进行了分析和仿真,并在此基础上提出了一种综合频率估计算法。该算法结合了上述2种算法的优点,在接收到达信号各频率区间和不同信噪比条件下,都可以满足到达信号频率检测的精度要求。

A FOA Estimation Approach for GALILEO/SAR Signal

In the GALILEO/SAR system,the accuracy of distress location estimation is dependent upon the accuracy of the frequency measurement of distress beacon signal received by MEOLUT.So it is significant to improve the accuracy of the FOA measurement in order to improving system locating accuracy.The character of the GALILEO/SAR distress beacon signal is analyzed first,and then based on the explanation of FFT method,the FOA detection method of the Rife algorithm and the Phase Difference Correction algorithm have been analyzed and simulated.The simulation results for the two frequency-estimation algorithms show that each of the two algorithms can do frequency-estimate with high precision in specific frequency range,but they can not meet the requirement of the system separately.A synthetic approach that combines the advantages of the two algorithms described above is presented in this article,and the simulation and the statistical analysis indicate that this synthetic approach can reach the requirement of the whole system.