多径相干信号到达角和衰落系数的最大似然估计

Maximum likelihood estimation of multi-path DOA and fading coefficient

针对多径相干信号到达角(DOA)和衰落系数(FC)的估计问题,在已知信号波形条件下,提出了一种联合估计DOA和衰落系数的改进最大似然估计方法。通过改进最大似然估计求极值获得DOA和衰落系数的解,在联合估计参数时,使用交替极大值技术,降低了估计算法的复杂度,并且推导了最大似然估计的Cramér-Rao界。理论分析和实验表明,该方法与现有方法相比具有更好的估计性能,当来自不同辐射源的多径信号中存在相同DOA时,仍然可以得到很好的估计效果。

Focusing on estimating the direction of arrival（DOA）and fading coefficient（FC）in multi-path coherent signal environment,this paper proposed a new approach by using the improved maximum likelihood estimation（IMLE）.This method estimated DOAs of multi-path coherent signals by using IMLE,gained FC and deduced Cramér-Rao boundary of IMLE.In order to drop the computational complexity of IMLE,used an alternating maximization（AM）method to reduce dimensions of the search space.The theoretical analysis and experimental results show that the proposed approach has better estimation performance than existing methods.Even if DOAs of multi-path coherent signals coming from different emitters are identical,the presented approach has still a good estimation effect