  In this work we consider the problem of downlink resource allocation for
proportional fairness of long term received rates of data users and quality of
service for real time sessions in an OFDMA-based wireless system. The base
station allocates available power and bandwidth to individual users based on
long term average received rates, QoS based rate constraints and channel
conditions. We solve the underlying constrained optimization problem and
propose an algorithm that achieves the optimal allocation. Numerical evaluation
results show that the proposed algorithm provides better QoS to voice and video
sessions while providing more and fair rates to data users in comparison with
existing schemes.
