Focusing on the problem that traditional resource allocation algorithms result in low spectrum efficiency
an adaptive sub-carrier allocation algorithm was proposed for orthogonal frequency division multiple access systems with minimum transmission rate request. In the algorithm
the utility value of each sub-carrier that can be achieved by different users is first evaluated based on users' minimum transmission rate request
the channel state and the current sub-carrier allocation state. Then
the sub-carrier is allocated to the user
who can achieve the maximum utility value. As both efficiency and fairness are taken into account in the algorithm
the performances of the system are improved remarkably. Simulation results show that
compared with algorithms which consider efficiency and fairness separately
when the number of users is within the system load
the frequency efficiency of the proposed algorithm increases by 10% and the system load within the same range of outage probability increases by 60%.
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references
KELLER T, HANZO L. Adaptive multicarrier modulation: a convenient framework for time-frequency processing in wireless communications [J]. IEEE Proceedings, 2000, 88(5): 611-640.
ROHLING H, GRUNHEID R. Performance comparison of different multiple access schemes for the downlink of an OFDM communication system [C]∥Proc IEEE Vehicular Technology Conference, Piscataway,USA: IEEE, 1997:1365-1369.
JIANG J, LEE K. Transmit power adaptation for multiuser OFDM Systems [J]. IEEE JSAC, 2003, 21(2): 171-178.
WONG C, CHENG R, LETAIEF K, et al. Multiuser OFDM with adaptive subcarrier, bit, and power allocation [J]. IEEE JSAC, 1999, 17(10): 1747-1758.
ZHANG Y, LETAIEF K. Multiuser adaptive subcarrier-and-bit allocation with adaptive cell selection for OFDM systems [J]. IEEE Trans Wireless Commun, 2004, 13(5):1566-1575.
SONG Guocong, LI Ye. Cross-layer optimization for OFDM wireless networks-part I: theoretical framework [J]. IEEE Trans Wireless Commun, 2005, 4(2):614-624.
SONG GUOCONG, LI Ye. Cross-layer optimization for OFDM wireless networks:part II: algorithm development [J]. IEEE Trans Wireless Commun, 2005, 4(2):625-634.
KIVANC D, LI Guoqing, LIU Hui. Computationally efficient bandwidth allocation and power control for OFDMA [J]. IEEE Trans Wireless Commun, 2003, 2(6):1150-1158.