A resource allocation strategy for cooperative multi-relay cognitive radio networks

Cognitive radio networks will play important role in future wireless networks. This paper proposes a new resource allocation strategy in cooperative multi-relay cognitive radio networks, in which multi second users can work as the relays of primary users to accelerate the data transmission when the channel between primary transmitter and primary receiver is weak. In the strategy, the data transmission slot is divided into two sub-slots. In the first slot, the primary user chooses suitable second users and sub-channels to relay primary user's data; and then, the second users who have been chosen as the relays select the remaining idle sub-channels to transmit their own data. In the second slot, the second users who work as the relays forward primary user's data by decode-and-forward (DF) protocol; meanwhile, second users select the remaining idle sub-channels to transmit their own data. Simulation results show that the resource allocation strategy proposed improve the throughput of the cognitive radio network obviously compared with the single relay.