子带分解在ESPRIT算法中的应用

Application of Subband Decomposition to ESPRIT Algorithm

ESPRIT算法是一种用于信号到来角(DOA)估计的直接求解方法,其性能在低信噪比(SNR)和信号相关时会严重削弱.基于此提出了一种多分辨率DOA估计算法基于子带分解的ESPRIT算法(SB-ESPRIT),通过对全带信号进行子带分解,并对每个叶节点分别应用ESPRIT算法,最后通过映射算法将估计所得的DOA映射到全带信号.对于子带分解后旋转不变性的证明为其应用提供了理论依据.仿真结果证明,SB-ESPRIT不仅提高了特征子空间方法的分辨率,而且在子带划分适当的情况下,具有一定的信号去相关能力,并且其均方误差(RMSE)小于ESPRIT算法.

ESPRIT algorithm is a direct DOA estimation method, of which the performance degrades greatly if the signal-to- noise ratio （SNR） is low and signals correlate with each other. A multi-resolution algorithm for DOA estimation is therefore presented, namely the subband-based ESPRIT algorithm （SB-ESPRIT）, which takes advantage of the subband decomposition of fullband signals then estimates the subband DOAs via ESPRIT method. A mapping-back manipulation is used to map the estimated subband spatial frequencies onto the fullband ones. The rotational invariance of the subband signals is also proven. Simulation results showed that SB-ESPRIT will not only improve the resolution of eigenstmcture-based method but also decouple the coherent signals if the subbands are properly decomposed. The root mean square error （RMSE） of SB-ESPRIT is also lower than that of ESPRIT.