Energy Efficiency (EE) is the important issue for multi-user Multiple-Input Multiple-Output - Orthogonal Frequency-Division Multiple Access (MIMO - OFDMA) system. In this paper, the Energy-efficient Multiple Access (EMA) schemes are proposed to improve EE by selecting either Time-Division Multiple Access (TDMA) or Space-Division Multiple Access (SDMA) for each subband, based on the number of users and power consumption. The polynomial-complex and greedy-based user assignment algorithms for the EMA system are adapted to Maximize energy efficiency. System complexity and energy efficiency are compared. Simulation Results verified that the EE of Greedy (GUSA) algorithms could significantly improve energy efficiency with practically compare to Fine EMA algorithm with increasing complexity.

Shivkanya. D. Jadhav and V. M. Harnal (2017). User Assignment Algorithm for Energy Efficient Multiple Access Scheme of MIMO-OFDMA Systems. International Journal of Computer Engineering In Research Trends, 4(11), 469-477. Retrieved from http://ijcert.org/ems/ijcert_papers/V4I1103.pdf

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