Spectrum Sensing and Optimal Media Access Control Layer Timings for Cognitive Radio
Paper ID : 1791-IST
1Ebrahim Saberinia *, 2Babak Abbasi Bastami
1University of Nevada Las Vegas (UNLV)
2University of Nevada Las Vegas
In this paper, we study a sensing-transmission scheme for secondary user in a cognitive radio system where the secondary user senses every primary channel independently and transmits a signal for a fixed duration if it finds the channel empty and stays idle for another fixed duration if it senses the channel busy. We find analytical expressions for the interference ratio on the primary user and access opportunity of the secondary user. Based on these expressions, we obtain optimal idle and transmission durations which maximize the access opportunity of the secondary user while keeping the interference ratio on the primary users below a threshold. Finally, we compare the performance of this scheme with another scheme where the secondary user keeps sensing the channel until finds it empty. Our results show that unless we have an error free perfect channel sensing, adding the idle duration improves the performance of the system.