Ultra-WideBand (UWB) technology offers the potential of achieving high ranging accuracy through signal Time-Of-Arrival (TOA) measurements, even in harsh enviroments due to its ability to resolve multipath and penetrate obstacles. This paper evaluates a joint TOA and DOA estimator compliant with the IEEE 802.15.4a Standard. The estimator proposed here is an adaptation of to comply with the Standard specifications. The estimation is developed in the frequency domain in order to exploit the high accurate time-based measures of the UWB signals.