A passive method of positioning indoor target based on TDOA

To improve the localization accuracy in a small scale of indoor environment a passive target localization method is presented. The indoor target localization system is consisted of four wireless transmitters which could transmit known signals. The receiver meaning the target passively receives four signals from the four signal transmitters and then calculates the propagation time differences of arrival (TDOA) between the any two transmitters and the receiver employing the cross correlation. As such, the four transmitters can draw three TDOAs, and the target position could be calculated using the geometric and algebraic arithmetic. Theoretical analysis and simulation results show that the proposed method can effectively locate the target location in a small range with less error brought by noise and multi-path propagation.