Interference Cancelation and Management Techniques

Radio spectrum is a scarce and precious natural resource that is signifi-cantly underutilized with current fixed spectrum-licensing policies [1].This has inspired the development of hierarchical spectrum-sharing sys-tems, where secondary systems are allowed to access the underutilized spectrum of incumbents without causing harmful interference to legacy/primary systems. In this article, we are interested in an important paradigm of secondary systems known as cognitive radio (CR) networks [2], [3], where the secondary terminals are envisioned to be capable of sensing and reasoning about the oper-ating radio environments and thereby autonomously adjusting their transceiver parameters to exploit the underutilized radio resources in a dynamic fashion. Because of its spectrum-sharing nature, a CR network inevitably operates in interference-intensive environments. Effective interferencemanagement is there-fore essential to the coexistence of primary and CR networks. Interference man-agement mechanisms can be embedded into a CR network in various aspects of system design from network planning, radio resource management, medium access control (MAC) to physical-layer signal processing. Our interest in this study lies on the physical-layer signal-processing schemes, commonly known as interference cancelation (IC) techniques. In the literature, only a few articles [4]