Energy-efficient and Mobile-aided Cooperative Localization in Cognitive Radio Networks

In cognitive radio networks (CRNs), primary users (PUs) localization is a key aspect to improve network performance in terms of reliability and power adaption. However, energy efficiency becomes a critical issue for localization in CRNs due to the limited energy storage in CR devices. In this paper we propose an Energy-Efficient Cooperative Localization Algorithm (EE-CLA) for PU positioning using a mobile-aided CR. Since cooperative communication among CRs is energy demanding, a mobile CR manager is introduced to balance the requirements for positional accuracy and power consumption restrictions by waking up only an appropriate number of CRs collaborating with the mobile CR manager. To investigate the influence of accurate location information, a location-aware CR (LaCR) routing protocol is also applied. Simulations are conducted to evaluate the performance of both proposed EE-CLA algorithm and LaCR protocol. Results confirm that the proposed EE-CLA outperforms its simplified version, named CLA algorithm, in terms of energy efficiency. Moreover, significant gains are obtained with the LaCR protocol in terms of CR end-to-end performance and PUs collision risk by using the localization information obtained from the EE-CLA algorithm.