A main problem of cognitive radio (CR) is how to optimize the spectrum sensing and power allocation parameters.In the traditional CR,spectrum sensing is only performed in the sensing phase,however,information in the decision-making and transmission phases are also useful for spectrum sensing.In this paper,a decoding information-based spectrum sensing strategy for transmission phase was proposed for CR system and the transmission power for the next phase was optimized correspondingly.In the transmission phase,after receiving the signals from the secondary transmitter,decoding was performed and the secondary transmission signals were removed.Then,the state of the primary user (PU) were detected based on the remainder signals,and the transmission power were optimized correspondingly.The simulation results showed that,on the case of certain average interference power to the PU,the proposed model provided better system performance and made better use of the channel.By fully using the signals in the transmission phase,the transmission parameters of the SU can be optimized and more information for spectrum sensing can be collected,leading to higher detection accuracy of the state of PU.
