A Multi-Band Power Allocation Scheme for Green Energy-Efficient Cognitive Radio Networks

Green cognitive radio has attracted significant research attention as an effective means of alleviating spectrum scarcity and energy-saving problem in wireless communications. In this paper, we focus on the power allocation for maximizing the transmission throughput and energy efficiency (EE) of secondary users (SUs). More specifically, we propose a multi-band power allocation scheme, where multiple idle spectrum bands detected in spectrum sensing phase are simultaneously utilized for the secondary transmission. We formulate the power allocation between multiple detected idle spectrum bands with the consideration of mutual interference between the primary user (PU) and SU which is referred to as multi-band power allocation (MBPA). We prove that the formulated MBPA problem is convex and consider the use of sequential unconstrained minimization technique (SUMT) interior point method for solving the formulated problem. Finally, numerical results show the advantage of proposed MBPA scheme over conventional equal-power allocation (EPA) and best-band selection (BBS) methods in terms of the energy efficiency.