Outage Analysis of a Multiple-Antenna Cognitive Radio System With Cooperative Decode-and-Forward Relaying

In this paper, we analyze a two-phase hierarchical spectrum sharing protocol based on cooperative decode and forward relay transmission wherein it is assumed that the cognitive (i.e secondary) system is equipped with multiple antennas. The performance of the licensed (i.e. primary) as well as cognitive system is quantified by deriving the closed form expressions for outage probability. The theoretical and simulation results show that by exploiting multiple antennas at secondary transmitter (ST), we can drastically improve the performance of both primary and secondary systems as compared to conventional spectrum sharing schemes.