Estimation of directions of arrival of wideband and wideband spread sources

The problem of estimating the direction of arrival (DOA) of wideband sources has always been of interest to the researchers because of its importance in many practical scenarios. The rising demand of communicating at higher data rates can be met by using wideband signals [R.U. Nabar, A. Paulraj, D.A. Gore, H. Bolcskei, An overview of MIMO communications—a key to gigabyte wireless, Proc. IEEE 92 (February 2004) 198–218]. Multipaths, scatterers etc., present near the transmitter render spatial bandwidth to these wideband signals. Traditional DOA estimation techniques, designed assuming point sources, result in serious performance degradation when applied to these wideband sources. This paper talks about the DOA estimation of spatially spread wideband sources i.e. sources having both spatial and temporal bandwidth. The interesting aspect of the approach presented is the usage of “spatial only” observations to estimate the DOA of both wideband point sources and wideband spread sources. Numerical simulation results verify the validity of the proposed method.