This paper shows the feasibility of an LTE signal fingerprinting Device Free Passive localization system. The experimental setup considers one single LTE receiver in the monitored room. The paper shows that when ambient signals such as LTE are used, the use of RSSI as fingerprint provides very poor performance. CSI-based approaches demonstrate much better performance. Moreover, the system using CSI shape and statistical descriptors rather than direct CSI vectors is characterized by more stable performance also when the room configuration is changed (i.e., the furniture is moved).