In this paper, a cooperative transmission protocol for cognitive radio systems is proposed. In this protocol, the\nprimary system comprises a transmitter (PT), a receiver (PR), and a decode-and-forward relay (Relay), while the\nsecondary system comprises a transmitter (ST) and a receiver (SR). Both the ST and the Relay assist the transmissions\nof the primary users together. The outage probabilities of the primary system and the secondary system are analyzed\nand verified through simulations. In order to decrease outage probability of the secondary system, power allocation\nis performed at the ST. However, it will lead to deterioration of outage performance of the primary system. In order\nto guarantee outage performance of the primary system, a Relay is employed. Compared with two existing protocols,\none without cooperation and the other with cooperation of the secondary system only, the proposed protocol\nis able to better balance outage performances of the primary system and the secondary system.
Loading....