A robust bearing estimator based on Jacobi-anger expansion for large angular spread source

摘要

In bearing estimation of angular spread source, the Taylor-expansion is commonly used, which may lead to a distinct model approximation error especially for the large spread case. In order to overcome this problem as possible, the JA-expansion model is employed in this paper. One side, the model accuracy mainly depends on the order of JA expansion but has no directive relation with angular spread; another side, as the coefficients of JA expansion for array response are just the harmonics of incident angle, thus the array covariance matrix can be computed exactly by Fourier transformation of angular power density. For symmetric angular spread, utilizing the structural knowledge of array covariance matrix and the decoupling property of JA-expansion model, a non-linear least squared estimator is proposed. Numerical results demonstrate its robustness for large angular spread and array size extension. Its asymptotic performance is also examined for the large sample case.