Resource allocation and power control in a TDD OFDM-based system for 4G cellular networks

Time division duplex (TDD) systems based on orthogonal frequency division multiplexing (OFDM) have recently been proposed as potential candidates for next generation (4G) cellular networks. In this paper, as a multiple access scheme we propose an adaptive frequency division multiple access (AFDMA), where resources are assigned to users exploiting channel knowledge at the transmitter. In order to reduce the system overhead, the algorithm can also work on group of sub-carriers and OFDM symbols. The proposed solution is shown, through numerical results, to be superior to conventional allocation strategies, namely time division multiple access (TDMA) and FDMA. Furthermore, we also investigate a new power control algorithm based on a single-user discrete bit loading technique. Numerical results are reported for both downlink and uplink transmissions in a multi-cell environment supporting real-time traffic

[1]  J.A.C. Bingham,et al.  Multicarrier modulation for data transmission: an idea whose time has come , 1990, IEEE Communications Magazine.

[2]  Otilia Popescu,et al.  Water filling may not good neighbors make , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[3]  D. Veronesi,et al.  On the capacity comparison of multi-user access techniques for fourth generation cellular TDD OFDM-based systems , 2005, 2005 IEEE 61st Vehicular Technology Conference.

[4]  Khaled Ben Letaief,et al.  Multiuser OFDM with adaptive subcarrier, bit, and power allocation , 1999, IEEE J. Sel. Areas Commun..

[5]  Otilia Popescu,et al.  Sum capacity and TSC bounds in collaborative multibase wireless systems , 2004, IEEE Transactions on Information Theory.

[6]  Didem Kivanc-Tureli,et al.  Computationally efficient bandwidth allocation and power control for OFDMA , 2003, IEEE Trans. Wirel. Commun..

[7]  Pravin Varaiya,et al.  QoS aware adaptive resource allocation techniques for fair scheduling in OFDMA based broadband wireless access systems , 2003, IEEE Trans. Broadcast..

[8]  Wei Yu,et al.  Iterative water-filling for Gaussian vector multiple-access channels , 2001, IEEE Transactions on Information Theory.

[9]  ALAN JONES,et al.  TDD-CDMA for the 4th generation of wireless communications , 2003, IEEE Wirel. Commun..