Relay Cooperation with Guard Zone to Combat Interference from an Underlaid Network

In this paper, we investigate the impact of relay cooperation for maintaining coverage area against aggregate interference from incumbent underlaid interferers. We employ a guard zone for uplink so that non-urgent interferers are inhibited and urgent ones are admitted with a controlled access probability as long as the primary receiver can tolerate. Numerical results show the outage probability of the primary relay network with the guard zone and that a desired quality-of-service (QoS) determines the access probability of urgent interferers depending on interfering node density.