Mobile Phone Passive Positioning Through The Detection of Uplink Signal

To satisfy the requirements of high-precision locating and life detecting after the disaster, this paper proposes a passive positioning method for locating the mobile phone by capturing the preamble sequence which can be applied to 4G even 5G communication system. We analyze the characteristics of the random access procedure of the communication system and present a way to detect the mobile phone combining the time difference of arrival (TDOA) estimation to solve the location. Then we do experiment and simulation of preamble sequence acquisition, and the result proves that the method is feasible and has high detection accuracy in high noise conditions.