Spatially-spread sources and the SMVDR estimator

A novel algorithm called spread minimum variance distortionless response (SMVDR) algorithm is proposed in this paper for the problem of parameter estimation of spatially spread sources. Traditional estimation techniques have been designed only for point sources. Each point source travels along a single path to an antenna array. However, in wireless communications, a source with multipath propagation is spatially spread from one direction to another direction around nominal direction-of-arrival (DOA). Therefore, the traditional estimation techniques which are based on point source assumption may result in serious performance degradation. Numerical experiments for the case of one Gaussian source have shown that SMVDR exhibits better performance than the subspace-based algorithms for spatially spread source parameter estimation. SMVDR is more computationally efficient than the subspace-based algorithms too. However, SMVDR can not reach the Cramer-Rao bound (CRB) in the example. Recall that the subspace-based methods do not reach the CRB either.