Power Reservation-Based Admission Control Scheme for IEEE 802.16e OFDMA Systems

Traditional admission control algorithms are based on bandwidth or channel reservation policy, which may be incompetent in IEEE 802.16e OFDMA systems for two reasons: (1) WiMAX system supports dynamic and flexible resource allocation, and (2) there exists a fundamental tradeoff between bandwidth resource and power resource. In this paper, we propose a novel admission control scheme based on power reservation. Foremost, we introduce a joint subchannel and power allocation algorithm for WiMAX system, which achieves high power efficiency by minimizing the overall downlink transmit power and utilizing all available subchannels. Based on this, we propose two power reservation schemes for inter-cell handoff calls and intra-cell handoff calls, respectively. Correspondingly, two reservation factors are introduced, the values of which are determined by optimizing the metric of grade of service(GoS). Computer simulation is carried out to evaluate the performance of the proposed admission control scheme.