On the effective capacity region for cognitive radio multiple access channels

This paper investigates the effective capacity region for a cognitive radio multiple access channel (CR-MAC) under the interference power constraint to protect the primary user (PU) transmission. A closed-form greedy power allocation policy which encourages exclusive transmission of the secondary users (SUs) is proposed to obtain an inner effective capacity region boundary. It is shown that the proposed policy is practically optimal for stringent interference power constraint and loose delay quality-of-service (QoS) constraint and the obtained inner bound on the effective capacity is thus tight.