Simplified Power Allocation Scheme for Cognitive Multi-Node Relay Networks

The simplified optimization problem is considered since the power allocation (PA) problem is the nonconvex optimization problem in cognitive multi-node relay networks, which has the interference on the primary user and the maximum transmission power constraint. The maximum transmission power constraint is guaranteed after we obtained the closed-form solution of the simplified optimization problem which has only the interference constraint on the primary user. The proposed PA method with much lower complexity performs close to the suboptimal PA method using interior point method.