Robust Cooperative Primary User Localization in Sensor Networks

Localization of primary user (PU) is a challenging problem in cognitive radio network, there are two reasons for this difficulty, first, NLOS propagation in complex wireless communication environment will cause errors in ranging data, second, PUs and secondary users (SUs) cannot communicate directly. In this paper, we propose a robust primary user localization method, which consists of two steps, in the first step, SUs perform relative localization based on ranging, the second step is that the cooperative method based on received signal strength difference (RSSD) is used to determine the location of the PUs. The proposed method has less computational burden and is suitable for mobile wireless sensor network (WSN) nodes with limited power, in addition, it doesn't rely on additional positioning equipment such as satellite and Wi-Fi, and can be deployed in indoor and underground mine environments. The effectiveness of the proposed method is verified by numerical simulations, when there are outliers in the ranging data, our method can effectively realize the localization of SUs, and then determine the location of PU through least square method.