Primary spectrum availability sensing for cognitive radio

Precluding the out of date spectrum hole is quite essential for cognitive spectrum sensing. Key factors in this problem include the primary users´ activity in time domain and the spectrum sensing triggers, etc. The Primary Spectrum Availability Sensing for Cognitive Radio is proposed in this paper. Renewal theory is introduced to derive the instant availability and the sensing cost. Numerical studies prove that the probability of up to date sensing result decreases and the sensing cost rises along with the time.