Locating primary users in cognitive radio networks by generalized method of moments

In order to avoid harmful interference to primary users (PUs), secondary users (SUs) in a cognitive radio network need some information about the primary network, such as the location of the active PUs. However, the advent of high-speed primary networks, e.g., LTE, has created a necessity for fast and accurate localization methods. In this paper, we propose a novel generalized method of moments-based localization technique that only requires the knowledge of traffic distribution and power allocation strategy of the primary network. Each SU is capable of efficiently locating any PU inside a certain geometric region using the received signal strength. The proposed method converges in linear time with respect to the number of signal power measurements to localize the PUs with high accuracy, as demonstrated by the simulation results. Moreover, we discuss the effect of the SU and PU locations on the localization performance.