In cognitive radio cellular networks (CogCell), the Secondary Users (SUs) can be admitted to the Base Station (BS) provided that the interference caused by SUs to the Primary Users (PUs) is no higher than the pre-defined threshold. In addition, different SUs may require different Quality of Service (QoS) and hence make different payment based on the provided QoS level. In this paper, we investigate the maximally achievable revenue obtained from SUs subjected to the interference constraints on PUs and QoS requirements of SUs. To solve the identified issue, we introduce the revenue efficiency factor and propose an efficient Joint Admission and Power Control scheme using a Minimal Revenue Efficiency Removal algorithm (JAPC-MRER). With comparison to the other two schemes JAPC-MSRA and JAPC-Random, our strategy is able to achieve much higher revenue with guaranteed interference requirements and QoS demands. In addition, the proposed scheme is evaluated with the effects of the key parameters, i.e. the number of PUs, the number of SUs and the interference threshold.