Combined Power Allocation in Cognitive Radio-Based Relay-Assisted Networks

The primary-secondary user combined power allocation problem is considered in this paper. The problem is addressed in cognitive radio-based relay-assisted networks, where the primary user and the secondary user coexist and influent on each other, and the relays are expected to undertake partial tasks of collecting channel information, computing the optimal power allocation strategy, and informing the users about the obtained transmit power results. The power allocation for primary and secondary user is modeled as a noncooperative game. The existence of the Nash equilibrium of the game is established, as well as its uniqueness. A relay-assisted iterative algorithm, which can be performed through the cooperation of the base station and the relays, is proposed to efficiently reach the Nash equilibrium. Numerical results demonstrate the convergence of the proposed iterative algorithm, and also the performance improvement of the power allocation.