The effects of local scattering on direction of arrival estimation with MUSIC and ESPRIT

In wireless communication scenarios, multipath propagation from local scatterers in the vicinity of mobile sources may cause angular spreading as seen from a base station antenna array. This paper studies the effects of such local scattering on direction of arrival (DOA) estimation with the MUSIC and ESPRIT algorithms. Previous work has considered rapidly time-varying scenarios, and concluded that local scattering has a minor effect on DOA estimation in such scenarios. This work considers the case in which the channel is time-invariant during the observation period. The distribution of the DOA estimates is derived, and the results show that local scattering has significant impact on DOA estimation in the time-invariant case. In addition, numerical examples are included to illustrate the analysis, and to demonstrate that the results may be used to formulate simple estimators of angular spread.