Aj. Weiss et B. Friedlander, PERFORMANCE ANALYSIS OF SPATIAL SMOOTHING WITH INTERPOLATED ARRAYS, IEEE transactions on signal processing, 41(5), 1993, pp. 1881-1892
The interpolated spatial smoothing algorithm is a computationally effi
cient method for estimating the directions of arrival (DOA's) of signa
ls, some of which may be perfectly correlated. It extends the spatial
smoothing method to arbitrary array geometries. In an earlier paper we
derived this algorithm and studied its properties. This paper provide
s a statistical performance analysis for the algorithm. Closed form ex
pressions for the covariance matrix of the DOA estimation errors are d
erived using a perturbation analysis. Evaluating these expressions for
specific cases and comparing them to the Cramer-Rao lower bound for t
he DOA estimates, provides insight into the statistical efficiency of
this algorithm. The formulas for the error covariance are quite genera
l, and can be specialized to provide results for other DOA estimation
algorithms as well.