Cross-layer adaptive techniques for throughput enhancement in wireless OFDM-based networks

ABSTRACT

Although independent consideration of layers simplifies wireless system design, it is inadequate since: 1) it does not consider the effect of co-channel user interference on higher layers; 2) it does not address the impact of local adaptation actions on overall performance; and 3) it attempts to optimize performance at one layer while keeping parameters of other layers fixed. Cross-layer adaptation techniques spanning several layers improve performance and provide better quality of service for users across layers. In this study, we consider a synergy between the physical and access layers and address the joint problem of channel allocation, modulation level, and power control in a multicell network. Since performance is determined by channel reuse, it is important to handle co-channel interference appropriately by constructing co-channel user sets and by assigning transmission parameters so that achievable system rate is maximized. The problem is considered for orthogonal frequency-division multiplexing, which introduces novel challenges to resource allocation due to different quality of subcarriers for users and existing transmit power constraints. We study the structure of the problem and present two classes of centralized heuristic algorithms. The first one considers each subcarrier separately and sequentially allocates users from different base stations in the subcarrier based on different criteria, while the second is based on water-filling across subcarriers in each cell. Our results show that the first class of heuristics performs better and quantify the impact of different parameters on system performance.

REFERENCES

• 1: [1] I. Koutsopoulos and L. Tassiulas, "Channel state-adaptive techniques for throughput enhancement in wireless broadband networks," in Proc. IEEE INFOCOM, 2001, vol. 2, pp. 757-766.
• 2: [2] R. A. Berry and E. M. Yeh, "Cross-layer wireless resource allocation," Signal Process. Mag., vol. 21, no. 5, pp. 59-68, Sep. 2004.
• 3: [3] J. Zander, "Performance of optimum transmitter power control in cellular radio systems," IEEE Trans. Veh. Technol., vol. 41, no. 1, pp. 57-62, Feb. 1992.
• 4: [4] S. A. Grandhi, R. Vijayan, and D. J. Goodman, "A distributed algorithm for power control in cellular radio systems," in Proc. 30th Allerton Conf. Communications, Control, and Computing, 1992, pp. 446-454.
• 5: [5] R. D. Yates and C.-Y. Huang, "Integrated power control and base station assignment," IEEE Trans. Veh. Technol., vol. 44, no. 3, pp. 638-644, Aug. 1995.
• 6: [6] S. Papavassiliou and L. Tassiulas, "Improving the capacity of wireless networks through integrated channel base station and power assignment," IEEE Trans. Veh. Technol., vol. 47, no. 2, pp. 417-427, May 1998.
• 7: [7] N. Morinaga, M. Nakagawa, and R. Kohno, "New concepts and technologies for achieving highly reliable and high-capacity multimedia wireless communication systems," IEEE Commun. Mag., vol. 37, no. 1, pp. 34-40, Jan. 1997.
• 8: [8] X. Qiu and K. Chawla, "On the performance of adaptive modulation in cellular systems," IEEE Trans. Commun., vol. 47, no. 6, pp. 884-894, Jun. 1999.
• 9: [9] J. Chuang and N. Sollenberger, "Beyond 3G: Wideband wireless data access based on OFDM and dynamic packet assignment," IEEE Commun. Mag., vol. 38, no. 7, pp. 78-87, Jul. 2000.
• 10: [10] Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: High-Speed Physical Layer in the 5 GHz Band, IEEE 802.11 WG, Sep. 1999.
• 11: [11] Intel Technol. J. vol. 8, no. 3 (WiMAX), Aug. 2004 [Online]. Available: http://www.intel.com/technology/itj/2004/volume08issue03/index.htm
• 12: [12] W. Yu and J. M. Cioffi, "FDMA capacity of Gaussian multi-access channels with ISI," IEEE Trans. Commun., vol. 50, no. 1, pp. 102-111, Jan. 2002.
• 13: [13] L. M. C. Hoo, B. Halder, J. Tellado, and J. M. Cioffi, "Multiuser transmit optimization for multicarrier broadcast channels: Asymptotic FDMA capacity region and algorithms," IEEE Trans. Commun., vol. 52, no. 6, pp. 922-930, Jun. 2004.
• 14: [14] C. Y. Wong, R. S. Cheng, K. B. Letaief, and R. D. Murch, "Multiuser OFDM with adaptive subcarrier, bit and power allocation," IEEE J. Sel. Areas Commun., vol. 17, no. 10, pp. 1747-1758, Oct. 1999.
• 15: [15] H.-J. Su and E. Geraniotis, "A distributed power allocation algorithm with adaptive modulation for multi-cell OFDM systems," in Proc. 5th IEEE Int. Symp. Spread Spectrum Techniques and Applications, 1998, vol. 2, pp. 474-478.
• 16: Robert Endre Tarjan, Data structures and network algorithms, Society for Industrial and Applied Mathematics, Philadelphia, PA, 1983
• 17: [17] H.-J. Su and E. Geraniotis, "Power allocation and control for multicarrier systems with soft decoding," IEEE J. Sel. Areas Commun., vol. 17, no. 10, pp. 1759-1769, Oct. 1999.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.4 PERFORMANCE OF SYSTEMS
      Subjects: Design studies

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Wireless communication
      C.2.3 Network Operations
          Subjects: Network management
  C.4 PERFORMANCE OF SYSTEMS
      Subjects: Performance attributes

  F. Theory of Computation
  F.2 ANALYSIS OF ALGORITHMS AND PROBLEM COMPLEXITY
      F.2.2 Nonnumerical Algorithms and Problems
          Subjects: Sequencing and scheduling

General Terms:
Algorithms, Design, Management, Performance

Keywords:
cross-layer design, multicell systems, orthogonal frequency-division multiplexing (OFDM), resource allocation