In the past few years the mobile network's telecommunication field has known a huge progress in term of developing new standards to enhance the quality of service (LTE, LTE-A, 5G Ω). Positioning techniques in LTE (Long Term Evolution) network are gaining more interest since the majority of mobile communication operators are deploying their 4G Solution all over the world. In this paper, we investigate the optimal mobile position tracking mean: the Kalman filter when integrated in the localization process. We present, also, a tool based on Matlab/Simulink, for simulating the LTE positioning reference signal (PRS) generation, transmission and reception in a realistic propagation environment. The received signal at mobile station will be proceeded to obtain the time difference of arrival estimates which are used to calculate the handset position and tracking the Mobile User (MU) in a noisy environment. The main purpose of this paper is to design and build a free realistic simulator for LTE positioning dedicated to academic researches.