In this paper we analyze the benefit of using phased arrays as the receiving antennas of indoor location systems. A 60 GHz code division multiple access carrier-based ultra-wide band positioning system for the simultaneous location of diverse markers is considered. The positioning error in an indoor environment is assessed when omnidirectional antennas are used at the receiving sensors and when they are substituted by beamforming antennas. Results show that beamforming systems can effectively mitigate the multipath effects and achieve positioning accuracies close to those achievable in free space scenarios. The performance of omnidirectional systems is severely degraded by multipath and multiple access interference.