Distributed channel and power allocation based on hybrid spectrum access in cognitive radio network

In cognitive radio network, sensing based spectrum sharing access (SSA) is proposed as a hybrid spectrum access scheme of opportunistic spectrum access (OSA) and spectrum sharing access. In this paper, we study the power and channel allocation under the hybrid spectrum access in multiple secondary user (SU) environment. Considering not only the interference caused to primary user (PU) and the average transmit power constraints, but also the different traffic demand of SUs and the interference among SUs existed in multiple SU environments, a distributed channel and power allocation algorithm are proposed to maximize the system throughput while satisfying the QoS of SU transmissions. With these inequality constraints, Lagrange dual composition method is introduced for this nonlinear optimization problem. Exact expressions of power allocation and the channel allocation scheme are derived under power and interference limits and QoS demands. Simulation results are presented to verify the influencing factors and advantage of the proposed algorithm compared to opportunistic spectrum access.