Abstract: To solve the power allocation collision in decentralized cognitive radio networks with asymmetric channel state information, a new Signaling Games (SG) based power control algorithm is proposed. The competitive secondary users allocate power using signaling games schemes to share channel state information without using common control channel. It could effectively guarantee primary users transmission and avoid power allocation collision among secondary users. Moreover, the equilibrium result is analyzed and the simulation results verify the validity of channel gain estimation and improvement of throughput of secondary users.