Cooperative communication in cognitive radio networks has been introduced as an important and efficient technique
to improve the transmission performance of PUs or SUs. In this paper, we consider a cooperative cognitive radio network
(CCRN) consisting of multiple primary users (PUs) and multiple secondary users (SUs), where each PU can choose one SU
as its relay node. To encourage the forwarding behavior of the SUs, PUs lease a fraction of their allocated spectrum to
the corresponding relay SUs, so that the SUs are capable of transmitting their own data packets. A centralized resource
management architecture is introduced and an energy efficiency based relay selection and power allocation scheme is proposed for the PUs and SUs. The optimization problem is formulated and solved based on a modified Kuhn-Munkres bipartite matching algorithm. Simulation results demonstrate the effectiveness of the proposed scheme.