Radio resource allocation for OFDMA cognitive cooperative system

In this paper, the problem of wireless resource allocation in OFDMA-based cognitive cooperative network is investigated. The objective is maximizing the throughput of primary users in a system in which cognitive users act as a relay for primary users. In our proposed scheme, while primary users achieved desire rate, they dedicate some subcarrier for cognitive users. We propose two different algorithms for cognitive users' subcarrier allocation. Finally, we indicate the performance improvement of primary users in both proposed subcarrier allocation algorithms. The numerical results show the second approach in which both sum rate and each primary user rate are considered surpass the first one. In the first algorithm, only sum rate of all primary users is taken into account.