The conflict between scarcity of spectrum resources and low spectrum utilization motivates the concept of cognitive radio,which allows secondary unlicensed users to borrow temporally unused spectrum bands from primary...The conflict between scarcity of spectrum resources and low spectrum utilization motivates the concept of cognitive radio,which allows secondary unlicensed users to borrow temporally unused spectrum bands from primary licensed users.Spectrum sensing is one of the key functionalities that enable spectrum hole discovery and interference avoidance.As single user spectrum sensing may experience performance degradation in harsh wireless environment due to fading and shadowing,user cooperation is introduced to exploit spatial diversity for better sensing performance.However,local sensing results must be transmitted via a control channel.The advantage of cooperative sensing can be compromised by bandwidth limitation of the control channel.To overcome this,a benching cooperative sensing scheme is proposed in this paper.This scheme can reduce time overhead of sensing information exchange under a communication constraint.Analytical results of periodic sensing efficiency are then deduced while sensing parameters are optimized.Based on these,a recursive sensing algorithm exploiting prior channel state information is developed.Numerical results are presented to demonstrate the potential of our scheme.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.60832008 and 60902001).
文摘The conflict between scarcity of spectrum resources and low spectrum utilization motivates the concept of cognitive radio,which allows secondary unlicensed users to borrow temporally unused spectrum bands from primary licensed users.Spectrum sensing is one of the key functionalities that enable spectrum hole discovery and interference avoidance.As single user spectrum sensing may experience performance degradation in harsh wireless environment due to fading and shadowing,user cooperation is introduced to exploit spatial diversity for better sensing performance.However,local sensing results must be transmitted via a control channel.The advantage of cooperative sensing can be compromised by bandwidth limitation of the control channel.To overcome this,a benching cooperative sensing scheme is proposed in this paper.This scheme can reduce time overhead of sensing information exchange under a communication constraint.Analytical results of periodic sensing efficiency are then deduced while sensing parameters are optimized.Based on these,a recursive sensing algorithm exploiting prior channel state information is developed.Numerical results are presented to demonstrate the potential of our scheme.
