Interference avoidance based on multi-step-ahead prediction for cognitive radio

Opportunistic spectrum access (OSA) which allows a secondary user to access channels when primary users are not transmitting has been considered a promising way to increase the spectrum efficiency. To coexist with the primary user in the same frequency band, the secondary user has to adopt strict interference control rules to avoid interference towards primary users. This paper proposes using interference time ratio (ITR) (i.e. the fraction of a primary user¿s burst that is interfered by secondary transmission) as a measure of how much the primary user is impacted by secondary user for OSA system. A scheme based on multi-step-ahead prediction is proposed to predict the ITR and control the ITR so that it does not exceed a predefined threshold. To further illustrate the proposed interference avoidance scheme, two cases with different primary user traffic model are studied and simulated. The simulation and analysis results show that within acceptable predicting step number, primary user¿s burst could be well protected and precise ITR control could be achieved through the proposed interference avoidance scheme.