Cross-layer transmission rate/power policy for cognitive multi-access networks with imperfect sensing

We consider an underlay cognitive radio network with a primary user and a secondary user transmitting to a common receiver. The secondary user senses the primary user´s channel to determine whether the primary user is active or idle. The secondary user´s transmission policy is determined via a probabilistic cross-layer algorithm in which the secondary user´s average packet delay is minimized subject to constraints on its average transmission power and the maximum probability of collision at the primary user. The proposed cross-layer algorithm determines the number of packets the secondary user transmits and the power policy used to transmit these packets.