Cooperative spectrum sensing, power and throughput tradeoffs in cognitive radio systems

In this paper, we study the throughput optimization problem and obtain the sensing time and transmit power tarde off, regarding high protection on the primary users. Throughput maximization is a key challenge in cognitive radio networks (CRNs) and it is a criterion for the performance assessment of these systems. Cognitive radio is the solution for scarcity of spectrum in use with the ability to sense the spectrum and share it by allowing the coexistence of unlicensed and licensed users without causing harmful interference on primary users (PUs) that leads to the efficient use of the spectrum. We focus on the throughput maximization in single and cooperative CRNs. For this purpose, we assume a spectrum sharing CRN in which we use the energy detector to optimize the sensing time and power allocation. We solve this optimization problem under some constraints on the average transmit and interference power, as well as the minimum probability of detection on the system. We analyze the simulation results which indicate the effect of sensing time, transmit power, channel attenuation and the threshold of the detection probability on the capacity of CRNs. Eventually, we observe that optimizing the transmit power and sensing time plays an important role in the throughput maximization of the system.