  In this work we propose an efficient resource allocation algorithm for OFDMA
based wireless systems supporting heterogeneous traffic. The proposed algorithm
provides proportionally fairness to data users and short term rate guarantees
to real-time users. Based on the QoS requirements, buffer occupancy and channel
conditions, we propose a scheme for rate requirement determination for delay
constrained sessions. Then we formulate and solve the proportional fair rate
allocation problem subject to those rate requirements and power/bandwidth
constraints. Simulations results show that the proposed algorithm provides
significant improvement with respect to the benchmark algorithm.
