Sensing and Power Allocation for Cognitive Radio with Multiple Primary Transmit Powers

In this letter, we consider a more practical scenario when the primary user (PU) transmits with multiple levels of power in a cognitive radio (CR) network. The optimal spectrum sensing algorithm at the secondary user (SU) that could discriminate the PU´s´ transmitting power is proposed and the related performance is analyzed. We also designed a new SU transmission strategy where one transmit power is found for each estimation of the PU´s power. The strategy is further optimized according to the SU´s achievable rate. In the end, we validate our study by various simulations.