Joint channel allocation and relay selection with multi-QoS provisioning in cognitive cooperative networks

Cooperative beamforming is an efficient way to make use of the cooperative diversity in the cognitive radio networks. In this paper, we consider a multi-user cognitive radio network where multiple relay nodes are selected to perform cooperative beamforming. Aiming to satisfy the multi-Quality of Service (multi-QoS) requirements involving delay, bandwidth and BER, we propose a system transmission scheme, which achieves the satisfaction of bandwidth requirements and delay minimization by the dynamic channel allocation with queuing, meanwhile, a mean channel gain based multi-relay selection is proposed so as to guarantee the end-to-end BER as well as keep lower complexity. The novelty of these strategies is that they satisfy the multi-QoS requirements from the aspect of two-hop level. Simulation results indicate that the proposed scheme can achieve better performance, with all QoS requirements satisfied.