Efficiency of a Cognitive Radio Link with Opportunistic Interference Mitigation

To increase spectrum utilization, cognitive radio allows concurrent secondary and primary transmissions as long as interference to primary users is constrained under a threshold. This research proposes an enhanced opportunistic interference mitigation scheme utilizing both successfully and unsuccessfully decoded primary packets to improve data rate of secondary transmission. Moreover, we propose an analytical model to investigate characteristic changes of the spectrum usage affected by the coexisting secondary transmission in terms of overall spectral efficiency. The interference mitigation scheme can be applied to realistic two-tier femtocell networks to enable robust communication against cross-tier interference thereby obtaining a substantial spectrum reuse gain.