关键词:

Abstract:

An adaptive bandwidth allocation mechanism (ABAM) is proposed to make full use of the bandwidths not occupied by the license users. Two-dimensional Markov chain is used to analyze the performance of ABAM in cognitive radio(CR) networks. The measurements such as the channel utilization are analytically obtained. Theoretical analysis and simulation show that the ABAM, which allows the CR calls to adaptively adjust their transmission bandwidth according to the occupied bandwidth of license calls, will effectively improve the channel utilization of the system as compared with the fixed bandwidth allocation mechanism.

Key words: cognitive radio networks, adaptive bandwidth allocation, Markov chain, quasi birth and death process, bandwidth utilization