Two-step hybrid self-localization using unsynchronized low-complexity anchors

Self-localization using unsynchronized low-complexity anchors has a number of attractive features. Traditional self-localization techniques are not suitable to this scenario or have their applicability limitations. In this paper, a two-step hybrid self-localization technique using unsynchronized low-complexity anchors is proposed, which can achieve two-dimensional (2-D) instantaneous localization for both mobile and fixed agents and eliminate the need for heading information of the agents. In the first step, an initial location estimate is obtained utilizing range information based on received-signal-strength (RSS) measurements. In the second step, differential angle-of-arrival (AOA) measurements are converted to range measurements with the aid of the first step location estimate. Finally, a two-step hybrid localization algorithm is obtained using all the measurements in the first step and the second step. Simulation results show that the two-step hybrid self-localization technique has relatively high accuracy even in the scenarios with large RSS-based ranging variances and medium AOA measurement variances.