Effects of Non-zero Bandwidth on Direction of Arrival Estimators in Array Signal Processing

We consider the impact of a small but non-zero bandwidth on narrow-band directionof -arrival (DOA) estimation using an array of sensors. We derive expressions for the DOA error for three commonly used array processing algorithms: MUSIC, ESPRIT and Weighted Subspace Fitting (WSF). The error expressions are found by a perturbation analysis of these algorithms for small relative bandwidths of the sources. We compare the perturbation-based error predictions to the exact deviation for some special cases of interest. This work has been supported by grants from the Swedish Institute, by NUTEK under project number 93--03103, and by the U.S. Army Research Laboratory under Contract DAAL01-93-C-0095. 1 Introduction In this paper we consider the effect of bandwidth on direction-of-arrival (DOA) estimates. Our problem is motivated by communications and sensor problems in which the bandwidths of the source signals, while small, may not be negligibly small, such as, e.g., in radar, acoustics and ..