Approximated Matching-Based Spectrum Access Algorithm for Heterogenous Cognitive Networks

We present a novel spectrum access scheme for open spectrum networks. Different from existing works, this work considers the scenario that contending secondary users have heterogeneous channel availability. It is proved to be NP hard to find the optimal spectrum assignment in this scenario. To solve this problem, a novel approximation algorithm is proposed which is based on the maximum weighted matching technique. The performance of the algorithm is evaluated through extensive simulations. Compared with the general optimal spectrum allocation scheme without considering the difference of spectrum availability, the experiments´ results demonstrate that the new matching based algorithm improves the network throughput significantly, generally by 20% to 60%. The algorithm´s computation complexity is also at a low level of 0(M*n²*m).