UWB based positioning: Cramer Rao bound for Angle Of Arrival and comparison with Time Of Arrival

In this paper we consider the potential of UWB (ultra wide band) signals for positioning. We consider both TOA (time of arrival) and AOA (angle of arrival) based methods. For the AOA method we use a linear array of equi-spaced elements. We derive the CRB associated with this method, without using the monochromatic assumption. The CRBs of both methods are compared. The analytical results are illustrated for UWB signals having the spectral occupation fulfilling the FCC emission mask. We show that, for far field conditions and practical numbers of antenna array elements, TOA outperforms AOA. However the accuracy provided by AOA is shown to be very interesting