Interference Avoidance in Cognitive Radio Networks Using Cooperative Localization

In the recent years, there has been a tremendous increase in the use of wireless medium and radio frequency spectrum due to the development of new types of wireless networks, applications, and enabling technologies. Consequently, the radio frequency spectrum is getting overcrowded due to this increasing demand. Traditionally, frequency bands are allocated to licensed users for their specific use. Cognitive radio allows secondary users to communicate using these frequency bands. However, this may result in interference to the primary users. Information of the relative positions of the primary and secondary users and the distance between them can be exploited to avoid this interference. In our work, we use cooperative localization strategy to determine the distance between the secondary and primary users. This distance information is then utilized to adjust the transmission power of the secondary nodes so that the interference threshold of the primary users is not exceeded. The proposed methodology is evaluated using simulation experiments. Different aspects of the proposed algorithm including location and distance estimation, channel availability, and channel capacity against transmission power and path loss are evaluated. The results show that the proposed scheme is able to achieve considerable gains as a consequence of interference avoidance.