Adaptive spectrum sharing algorithm based on interference alignment

When interference alignment (IA) is applied to cognitive radio (CR) network, the signal-to-interference-plus-noise ratio (SINR) of the primary user (PU) may decrease under some status of the channel. This may affect the quality of the PU's communication. This paper proposed an adaptive spectrum sharing algorithm based on IA. According to the desired signal's SINR of PU, the proposed algorithm adjusts adaptively in the cooperative approach between PU and SUs, and shares the licensed spectrum on the premise of guaranteeing the PU's communication quality. The simulation analysis showed that the problem of the decrease of PU's communication quality in spectrum sharing based on IA is resolved effectively by the proposed algorithm. And the SU's accessing probability was improved while guaranteeing PU's performance.