基于改进MUSIC算法的宽带DOA估计  

Broadband DOA estimation based on an improved MUSIC algorithm

作　　者：张涛涛[1] 张兴敢[1] 

机构地区：[1]南京大学电子科学与工程学院,南京210023

出　　处：《南京大学学报（自然科学版）》2016年第5期932-938,共7页Journal of Nanjing University（Natural Science）

基　　金：江苏省基础研究计划(BK20151391)

摘　　要：经典MUSIC算法的统计特性主要建立在阵元数固定且快拍数趋于无穷的情况下,在有限样本中,当快拍数无法满足远大于阵元数的条件时,DOA估计会产生偏差.对于宽带信号的DOA估计,利用相干信号子空间(Coherent Signal-subspace Method,CMS)方法,构造聚焦矩阵使不同频率的信号子空间映射到同一参考频率上,用聚焦后的频域窄带模型进行DOA估计,并针对在实际应用中,阵列的阵元数较大且快拍数受限时经典MUSIC算法估计精度不高的情况,利用改进后的MUSIC算法-Spike-MUSIC算法,提高DOA估计精度.在不同信噪比下,分别对DOA估计的误差进行了MonteCarlo仿真实验,仿真结果表明,相对于普通的CSM方法,基于Spike-MUSIC算法改进的CSM方法在宽带DOA估计中具有更高的精度.The traditional DOA estimation algorithm for narrowband arrays is sensitivity to the signal bandwidth ,its performance declines while the bandwidth becomes larger .This paper uses coherent signal‐subspace method（CMS）to study on the DOA estimation for broadband signals .The coherent signal‐subspace method （CMS）maps the signal subspaces of different frequencies to the same reference frequency by constructing the focusing matrix .The result of broadband DOA estimation can then be approximated by a narrow band model in the frequency domain .The traditional MUSIC algorithm has been widely used in narrowband DOA estimation because it offers a good trade‐off between performance and complexity .Its statistical performance has mainly been characterized in the case where the number of snapshots converges to positive infinity while the number of antennas remains fixed .In practical ,the cor‐responding conclusion is valid only when the number of snapshots is much larger than that of antennas in finite sample size .However ,the number of antennas is large in practical and the number of available snapshots is limited . When both the number of antennas and that of snapshots converge to positive infinity at the same rate ,the DOA es‐timators of MUSIC algorithm will be asymptotically biased .In this paper ,Spike‐MUSIC algorithm is applied to CSM to improve the accuracy of DOA estimation for broadband signals ,the error of DOA estimation is simulated＆amp;nbsp;under different signal to noise ratios ,the simulation experiments show that when compared to CSM ,the improved CSM based on Spike‐MUSIC algorithm can estimate DOA with higher accuracy .

关 键 词：DOA估计 相干子空间方法 聚焦矩阵 Spike-MUSIC算法 

分 类 号：TN957.51[电子电信—信号与信息处理]