A NOVEL CROSS-LAYER ALGORITHM FOR ADAPTIVE PROPORTIONAL RESOURCE ALLOCATION IN MULTIUSER OFDMA SYSTEM

In Orthogonal Frequency Division Multiple Access (OFDMA) System, multiple users were allowed by base stations to transmit simultaneously different subcarriers during the same symbol period. In this paper, utility function was used to build a bridge between the physical layer and upper layers. And rate proportionality constraints were used to balance the efficiency and fairness of the radio resource allocation. Previous allocation methods based utility considered instantaneous conditions. In reality, however, users mainly cared about the average data rate during a certain period of time, not the instantaneous one .So a novel Adaptive Subcarrier Allocation-Greedy Power Allocation (ASA-GPA) algorithm based on utility function with discrete average rate adaptations was proposed. The performance of the proposed algorithm was studied through simulations. Compared with others approaches, the simulations results showed that the algorithm we presented indicated significant performance improvement.