Multiuser subcarrier allocation for QoS provision in the OFDMA systems

In this paper we consider the problem of resource (subcarrier and transmit power) allocation for QoS (quality of service) support in OFDMA systems with fixed modulation per subcarrier. We identify the key QoS parameters, such as bit rate and bit error rate, which are then used to determine the individual users' traffic demands. We propose an extension of Wong's (1999) algorithm, which distributes subcarriers and transmit power among multiple users according to their QoS traffic requirements. The new scheme, available in optimal and suboptimal version, is less complex than most of the existing methods. Due to its orientation on individual traffic requirements, it does not waste resources in a worst-case design. This results in a better performance compared to the Wong's algorithm. Moreover, we fit the considered resource allocation algorithm into a general contract-based QoS/CoS (cost of service) framework, which allows for efficient management of resources on the system level.