A link adaptation based call admission control algorithm for OFDMA systems

This paper presents a new call admission control (CAC) algorithm that takes into account the effect of mobility of users and adaptive modulation and coding (AMC) scheme, which can be used in orthogonal frequency division multiple access (OFDMA) systems with link adaptation. When the cell is decomposed into several concentric circles, time-frequency resources required for various traffics can be determined accurately, while resources reserved for handoff and AMC mode changed calls/connections or even new connections can be calculated according the AMC scheme of the users, so as to guarantee the connection-level performance. The proposed algorithm can provide the quality of service (QoS) requirements by taking advantage of the probability distribution of total traffics in the cell to determine the resource consumption. The performance of the proposed algorithm is analyzed with BCMP queuing network model. The simulation results verify the packet-level and connection-level performance of the proposed CAC algorithm.