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Cooperative localization of primary users by directional antennas or antenna arrays: Challenges and design issues

In this contribution we address the problem of cooperative localization of primary users in cognitive networks. We formulate this problem as a special case of Bayesian tracking, where multiple secondary users obtain direction-of-arrival (DoA) measurements from the target primary user by means of directional antennas, multi-antenna receivers, or virtual arrays. As opposed to typical settings, time-of-arrival (ToA) measurements are not available due to unknown transmission power of primary users and propagation channel. We then highlight some of the key research challenges related to this problem, including DoA estimation, (virtual) array configuration, and information fusion.