A cooperative DoA-based algorithm for localization of multiple primary-users in cognitive radio networks

Knowledge about the location of licensed primary users (PU) could enable several key features in cognitive radio (CR) networks including improved spatio-temporal sensing, intelligent location-aware routing, as well as aiding spectrum policy enforcement. In this paper we discuss the problem of localizing multiple PUs based on direction-of-arrival (DoA) measurements. The key problem in such scenario is the difficulty and complexity of associating multiple DoA measurements to different PUs. We propose an iterative method that uses the probability of associating each DoA to a PU as the weighting coefficient of a modified Stansfield algorithm for DoA fusion. Results show the proposed algorithm obtains better accuracy than previous algorithms [1]-[3], and its complexity increases linearly with the number of CRs, compared with the exponential rate for algorithms based on exhaustive search of all possible associations.