Sliding-Window Algorithm for Asynchronous Cooperative Sensing in Wireless Cognitive Networks

To improve the performance of spectrum sensing, cooperation among Cognitive Radios (CRs) has been proposed recently as an effective solution. Most existing works require either time synchronization or extra infrastructure support, which are not always practical. This paper proposes an asynchronous spectrum sensing framework which is of high accuracy, short response time and ease to implement. Within such a framework, each node uses our proposed Sliding-Window algorithm to analyze the spectrum status with the sensing results received from its neighbors. This algorithm maintains a minimal and sufficient number of sensing results using Sliding-Window method, and applies Likelihood Ratio Test (LRT) on them to make a decision. This algorithm is evaluated both in theory and by simulations. The results proved that our proposed cooperative sensing solution can show good performance in various situations.