On optimal sensing time and power allocation for energy efficient cooperative cognitive radio networks

A cooperative cognitive radio (CR) network that accomplishes both spectrum sensing (SS) and sharing is considered in this work. System model is assumed to be a cognitive ad hoc network that consists of multiple secondary transmitter (ST) and receiver (SR) pairs sharing transmission over a spectrum with a primary network of single transmitter-receiver pair. Based on SS outcome, secondary users (SUs) either cooperate in primary user´s (PU) transmission or proceed with its own transmission. The overall goal is to maximize energy efficiency for SU networks in terms of self and cooperative transmission. A set of optimal values for sensing duration, self and cooperative transmission power gains are calculated under the constraints of PU detection probability, SU power budget, PU and SU throughput. A large set of simulation results highlight the optimal performance gain of the proposed system.