Resource allocation in delay-QoS constrained multiuser cognitive radio networks

This paper considers a cognitive radio network where multiple secondary users (SUs) sharing multiple channels with the primary user (PU). The SUs are assumed to carry delay-sensitive services, thus the concept of effective capacity, which is defined as the maximum supported constant arrival rate under the delay quality of service (QoS) constraint, is adopted. Beside the delay QoS constraint, the interference power constraint and the transmit power constraint are also considered. The problem of joint channel allocation and power allocation to maximize the sum effective capacity of the SUs under the aforementioned constraints is investigated. A heuristic joint channel and power allocation scheme is proposed. It is shown that the proposed scheme achieves significantly higher sum effective capacity compared to the reference scheme, especially for stringent interference power constraint and loose transmit power constraint. It is also shown that the sum effective capacity is more sensitive to the variation of the delay QoS constraint under loose delay QoS constraint than that under stringent delay QoS constraint.