Cooperative DoA-only localization of primary users in cognitive radio networks

In this paper, we investigate localization techniques based on direction-of-arrival (DoA) measurements to estimate the position of primary users in cognitive radio networks. In the proposed approach, different multi-antenna sensors estimate the DoA of a primary signal by subspace-based techniques and the target position is estimated from the available DoA measurements using maximum-likelihood, least-squares, or Stansfield estimators. The resulting localization performance is evaluated numerically and compared to the Cramr-Rao bound derived under a considered problem setting. The impact of several system parameters (in particular, number of sensors and number of antennas per sensors) is thoroughly analyzed and discussed.