Outage Performance of Cognitive Radio Wireless Network with Secondary Relaying

In this paper, we investigate the outage performance of cognitive radio wireless network where secondary receiver does not suffer any interference from the primary user. In particular, we consider a system model that has a pair of primary transmitter and receiver as well as a pair of secondary transmitter and receiver, with a number of nearby idle secondary users acting as relays. Secondary relays help to maintain or even improve the outage performance of primary user while facilitating simultaneous secondary user transmission. We derive analytical results for the outage performance of primary and secondary link to prove the efficiency of proposed protocol. Simulations results demonstrate that the proposed protocol achieves large ergodic capacity and diversity gain for primary user while achieving substantial outage capacity for secondary user.