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.