Proposed Scheme for Maximization of Minimal Throughput in MIMO Underlay Cognitive Radio Networks

In cognitive radio networks (CRNs), the most critical issue is to increase the secondary throughput while assuring the quality of service of primary users (PUs). In this paper, a proposed optimal power allocation scheme using genetic algorithm is suggested for a multiple-input-multiple-output (MIMO) system in CRN. This scheme is used to maximize the secondary throughput under interference constraints in a system model of multiple secondary user (SU) pairs coexisting with multiple PU pairs in an underlay spectrum sharing network. For the sake of comparison, the minimal throughput among all SUs is compared with other power allocation schemes, namely, maximum–minimum-throughput-based power assignment (MMTPA) and equal power assignment (EPA). Simulation results show that, our proposed scheme gives the maximum–minimum secondary throughput among all other stated schemes. Moreover, unlike MMTPA, our proposed approach maximizes the throughput of all SUs not only the minimal throughput among all SUs.