  RFID has been widely used in applications for indoor objects location. This
article proposes a 3D location algorithm based on a system that uses a mobile
reader and a reference matrix of real (passive) and virtual tags. The proposed
algorithm compares the RSSI of the target tag with the RSSI of the tags of the
reference matrix and defines the estimated position. Preliminary results show
that the location scheme may be promising for indoor location of tags.
