采用数据辅助的单通道同频混合信号参数估计方法

在非合作卫星通信中，针对具有固定帧长及帧同步序列的单通道同频混合信号的参数估计问题，提出了一种基于数据辅助的参数估计算法。该算法先对帧长及帧头起始位置进行估计，并提取帧同步数据构建辅助函数。在与混合信号做相关运算后去除干扰项，峰值搜索得到频率偏移的精确估计值；使用辅助函数简化混合信号，随后基于最大似然估计理论，实现对信号初相信息的提取。在算法研究的基础上，推导了单通道同频混合信号参数估计的修正克拉美罗界，为算法的性能分析提供了理论依据。仿真结果表明，当帧同步信号达到一定数量时，频率偏移估计方差达到10-7，初相估计方差达到10-3，性能接近MCRB理论界。

Parameter Estimation of Single Channel Co Frequency Mixed Signal Using Data Assisted

A parameter estimation algorithm based on data assistance is proposed to estimate the parameter estimation problem of single channel co frequency mixed signal with fixed frame length and frame synchronization sequence in non cooperative satellite communication. First, the algorithm estimates the frame length and the beginning position of the frame head and extracts the frame synchronization data to construct the auxiliary function. After correlating with mixed signals, the interference term is removed, and the precise estimation of frequency offset is obtained by peak search. The auxiliary function is used to simplify the mixed signal, and then the initial information of the signal is extracted based on the maximum likelihood estimation theory. Finally, the estimation of the signal frequency offset and the initial phase of the signal is realized. Based on algorithm research, the modified Cramer-Rao bound for parameter estimation of single-channel co frequency mixed signals is derived, which provides a theoretical basis for the performance analysis of the algorithm. The simulation results show that when the frame synchronization signal reaches a certain number, the variance of frequency offset is 10-7, and the initial phase variance is 10-3.The performance of the algorithm is close to the MCRB theory.