Research on fourth-order MUSIC algorithm for virtual arrays
Ling Guo-min · Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University · 2007
A virtual array expansion technique based on the fourth-order(FO) cumulant was studied,whereby the array processing aperture and the spatial degrees of freedom were expanded.As a result,bearing estimation performance was improved.Since each of the redundant terms of the steering vector in the cumulant domain was seen to be equivalent to the response of an assumed element at a specific position,the virtual aperture could be virtually expanded using higher-order cumulants.The virtual array covariance matrix was estimated by averaging all the FO cumulants with the same equivalent inter-element cross correlations and utilizing the fact that the second order statistics were derived from the FO cumulants.The incoming signal direction was found with the MUSIC algorithm.Numerical analysis and results from a lake trial show that the resolution is increased and estimation variance is reduced by the virtual array MUSIC algorithm,and it is robust with spatial colored Gaussian noise.