QoS aware power allocation for combined guaranteed performance and best effort users in OFDMA systems

One of the key issues in design of an orthogonal frequency division multiple access (OFDMA) based system is subcarrier and power allocation. Assuming knowledge of the instantaneous channel gains for all users, we propose a resource allocation scheme for an OFDMA based system to simultaneously provide two services, guaranteed performance (GP) and best effort (BE), with different quality-of-service (QoS). Subcarrier and power allocation are carried out sequentially to reduce the complexity, and an optimal power allocation procedure is derived. Furthermore, we present a reduced complexity suboptimal power allocation algorithm.