基于TP的伽利略搜救信号参数估计算法

TP-Based Parameter Estimation Algorithm for Galileo Search and Rescue Signal

针对伽利略搜救系统信标信息提取时对FOA、信息位宽和TOA的高精度估计要求,考虑到用户信息未知,提出基于TP(纯载波和位帧同步信息)的多维联合极大似然估计算法和体积重心算法相结合的FOA、信息位宽、TOA估计算法。推导算法原理,并根据参数之间的相关性将估计过程分为两步完成。Monte Carlo仿真和实测结果表明,在34.8dBHz的处理门限下,FOA、信息位宽、TOA估计的均方根误差分别小于0.14Hz、2.5μs和30μs,优于其他算法估计性能,为信标信息提取提供了保障。该算法目前已应用于伽利略MEOLUT地面站。

According to the high precision demand of FOA,message bit width and TOA estimation when decoding the beacon message in Galileo Search and Rescue system,and considering that users' messages are unknown,a new FOA,message bit width and TOA estimation algorithm based on TP(Tone and Preamble,means un-modulated carrier and bit,frame synchronization messages)is proposed.The algorithm combines the multiple dimensions joint Maximum Likelihood Estimation algorithm and Barycenter calculation algorithm.The principle of the algorithm is derived and the estimation procedure is divided to two steps according to the correlation of the parameters.Monte Carlo simulation results and measurement results show that when CNR equals to the threshold of 34.8dBHz,FOA,message bit width and TOA estimation rmse(root-mean-square error) of the algorithm are respectively within 0.14Hz,2.5μs and 30μs,which are better than the rmse of other algorithms.The estimation precisions above provide guarantee for the beacon message decoding and this algorithm has been applied to the Galileo MEOLUT station.