Effective capacity limits of cognitive radio networks under peak interference constraint

In cognitive radio networks, a cognitive user (CU) can share the same frequency band with the primary user (PU) as long as the interference introduced to the PU is below a given interference limit. In this paper, we study the performance limits of CU's effective capacity by taking the instantaneous quality of services (QoS) of the PU into consideration. Considering the case with either single or multiple primary receivers, we derive closed-form expressions for the effective capacity for both of the above scenarios. We further analyze the performance limits of the asymptotic capacity when the received signal bandwidth approaches infinity, and obtain the closed-form expressions by taking both single and multiple primary receivers into consideration. Numerical results are provided to confirm the effectiveness of our theoretical analysis.