Intelligent dynamic spectrum allocation with bandwidth flexibility in cognitive radio network

Cognitive radio (CR) is a popular wireless technology for efficient utilization of spectrum. CR network senses the unused frequency bands of the primary users (PUs) and assign them to the unlicensed secondary users (SUs). One of the major challenges in cognitive network is the allocation of available spectrum which indirectly contributes to the efficient spectrum utilization. A novel intelligent dynamic spectrum allocation with bandwidth flexibility is presented in this paper. Fuzzy inference system has been used to evaluate and rate the channel (CH) quality and the SU. The quality based spectrum allocation has been carried out. As the primary CH bandwidth differ from the SU and in the case, the SU bandwidth is lower to PU, accommodation of more than one secondary CH into primary is possible. To utilize this facility, bandwidth flexibility is incorporated in the intelligent spectrum allocation. The intelligent spectrum allocation techniques are compared with the sequence based method of spectrum allocation and priority based allocation. The quality measures utilized for comparison are service rate, average packet loss and average delay. On these measures intelligent dynamic bandwidth flexible spectrum allocation method is found to be better, compared to other three methods.