Adaptive cooperative spectrum sensing using random access in cognitive radio networks

In this paper, a new adaptive cooperative spectrum sensing scheme using random access is proposed in a cognitive radio network. Cooperative spectrum sensing improves spectrum sensing performance considerably. In typical cooperative spectrum sensing situations, spectrum sensing data of several secondary users are collected before sensing decision. Yet how to collect the sensing data is not an easy problem because coordination between secondary users is needed. This study addresses this problem. The proposed scheme uses random access to report the sensing data of the secondary users. In this scheme, it is necessary to determine the length of the sensing data collection period. In the proposed scheme, the length of the sensing data collection period is determined adaptively based on the current status of the collected sensing data. We apply backward induction approach to decide when to stop the collection procedure of the sensing data. The proposed scheme does not need complex slot management to collect sensing data and shows performance improvement over conventional methods.