Cross-layer admission control based on service upgrading/degrading in CDMA systems with successive interference cancellation

In CDMA systems with successive interference cancellation (SIC), conflicting quality of service (QoS) requirements at different protocol layers must be traded off carefully when designing the admission control (AC) policy at the network layer, especially, the adjustment of decoding orders at the physical layer should be taken into account, and thus the cross-layer AC needs to be considered. Moreover, due to the elastic traffic characteristic of data services, the service level of this kind of users can be upgraded or degraded according to the situation of system load such that the overall system performance will be improved. In this paper, we study the AC policy in CDMA systems with SIC and propose a cross-layer AC algorithm based on service upgrading/degrading, where the aspects of the power constraint and decoding order adjustment at the physical layer are taken into account. We conduct extensive simulation experiments, and the numerical results demonstrate that by our proposed algorithm, the overall system performance such as throughput will be increased meanwhile more users can be admitted into the system.