  In this paper, Long-Term Proportional Fair (LTPF) resource allocation
algorithm in dynamic OFDMA system is presented, which provides long-term QoS
guarantee (mainly throughput requirement satisfaction) to individual user and
follows every user's QoS profile at long-term by incremental optimization of
proportional fairness and overall system rate maximization. The LTPF algorithm
dynamically allocates the OFDMA sub-carriers to the users in such a way that in
long-term the individual QoS requirement is achieved as well as fairness among
the users is maintained even in a heterogeneous traffic condition. Here more
than maintaining individual user's instantaneous QoS; emphasis is given to
follow mean QoS profile of all the users in long-term to retain the objectives
of both proportional fairness and multi-user raw rate maximization. Compared to
the algorithms, which provide proportional fair optimization and raw-rate
maximization independently, this algorithm attempts to provide both kinds of
optimizations simultaneously and reach an optimum point when computed in
long-term by exploiting the time diversity gain of mobile wireless environment.
