—In this paper, a user-aided adaptive TDMA (UAAT) algorithm is developed for real-time services to improve the system efficiency of OFDM based cellular networks. In the UAAT scheme, a subchannel is shared by multiple users adaptively in a TDMA manner based on their instantaneous channel conditions. The system efficiency is improved dramatically by applying adaptive modulation schemes to all real-time users and using each subchannel more efficiently. The performance of the proposed algorithm is evaluated and compared with that of other resource allocation schemes. Results show that the proposed algorithm provides up to 100% improvement in the system efficiency or, equivalently, the user capacity of OFDM based cellular networks.
Changqin Huo, Abu B. Sesay, Abraham O. Fapojuwo