18 from cell center to the edge of the cell. It is observed that the performance gap increases between the centralized and distributed schemes as users approach the boundaries of the cell. In this paper, we developed an upper bound and a lower bound to the optimal average network throughput in multi-cell uplink OFDMA networks. We also investigated the severe effects of ICI on the performance of a single cell near optimal resource allocation scheme. Moreover, we proposed a benchmark centralized scheme which is useful to study the performance gap of the low complexity centralized and distributed resource allocation schemes developed later with respect to the optimal solution. All schemes are compared to the exhaustive search based optimal solution and derived upper and lower bounds for various scenarios. The schemes are evaluated and compared in terms of network throughput and computational complexity. VII. CONCLUSION VIII. ACKNOWLEDGEMENT The authors would like to express their sincere gratitude to Dr. Elias Yaccoub for useful discussions toward the success of this work. REFERENCES [1] G. Li and H. Liu, “Downlink radio resource allocation formulti-cell OFDMA system,” IEEE Transactions on Wireless Communications , vol. 5, no. 12, pp. 3451–3459, 2006. [2] K. Kim, Y. Han and S-L Kim, “Joint subcarrier and power all ocation in uplink OFDMA systems,” IEEE Communications Letters , vol. 9, no. 6, pp. 526–528, June 2005. [3] C. Ng and C. Sung, “Low complexity subcarrier and power al location for utility maximization in uplink OFDMA systems,” IEEE Transactions on Wireless Communications , vol. 7, no. 5 Part 1, pp. 1667–1675, 2008. [4] Y. Ma, “Constrained rate-maximization scheduling for u plink OFDMA,” Proceedings of IEEE Military Communications Conference, (MILCOM’07) , pp. 1–7, Orlando, Florida, October 2007. [5] E. Yaacoub, A. M. El-Hajj, and Z. Dawy, “Weighted ergodicsum-rate maximization in uplink OFDMA and its achievable rate region,” IET Communications Journal , vol. 4, no. 18, pp. 2217–2229, 2010. [6] J. Huang, V. Subramanian, R. Agarwal, and R. Berry, “Join t scheduling and resource allocation in uplink OFDM Systems for broadband wireless access networks,” IEEE Journal Selected Areas of Communications , vol. 27, pp. 226–234, February 2009. DRAFT March 19, 2018