Abstract:

In order to effectively improve the spectrum sharing performance in cognitive radio network, considering the transmission quality and channel utilization with centralized control mode, the spectrum aggregation strategy for primary users is investigated. For an aggregated spectrum consists of multiple channels, considering that primary users have higher priority to secondary users, a discrete time queueing model with multiple servers and synchronous transmission interruption is built. Using the method of matrix geometric solution, the steady state distribution of the system is given. Accordingly, performance measures in terms of blocking ratio of primary users, average delay of secondary users and channel utilization are derived. Experimental results show that when setting the spectrum aggregation capacity, there is a trade-off between different performance measures. By establishing a system cost function, the scheme for setting spectrum aggregation capacity is carried out, and the spectrum aggregation strategy in cognitive radio networks is optimized.

Key words: cognitive radio networks, spectrum aggregation, multiple channels, discrete time queuing model, matrix geometric solution