Performance enhancement of cognitive radio spectrum sharing (CRSS) with MIMO system

A key challenge in operating cognitive radios (CRs) in a self-organizing (ad hoc) network is to adaptively and efficiently allocate transmission powers and spectrum among CRs according to the surrounding environment. Cognitive radio networks provide high bandwidth to mobile users via heterogeneous wireless architectures and dynamic spectrum access techniques. CR networks inflict challenges due to the fluctuating nature of the available spectrum, as well as the diverse QoS requirements of various applications. This paper considers a multiuser spectrum sharing (SS) system operating in a different fading environment and every node in the system is equipped with multiple antennas. The system employs orthogonal space-time block coding at the secondary users. The average capacity and error performance under a peak interference constraint are analyzed for this system using the distributed algorithm. For a comparison purpose, an analysis of the transmit antenna selection scheme is also presented.