Performance of collaborative techniques for simultaneous sensing and transmission in cognitive radio networks

Maximizing the secondary cognitive radio network throughput under the restriction of avoiding interference to the primary network is a main concern in recent research. In the classic approach, a specific interval is devised to the task of spectrum sensing, which penalizes the secondary network throughput. Aiming at a higher throughput than in this classic approach, the continuous sensing mode can be adopted. In this mode, secondary receiving nodes sense the spectrum while other secondary users simultaneously transmit in the same frequency band. This paper compares, under the continuous sensing approach, the performances of centralized cooperative spectrum sensing techniques. The maximum eigenvalue detection and the energy detection techniques are considered. In what concerns the fusion rules, we consider the sample fusion, the decision fusion and a recently proposed eigenvalue fusion technique. It is shown that, in spite of the intrinsic interference present in the continuous mode, this approach is flexible in terms of the sensing time, eventually allowing for better sensing performance.