Spectrally Efficient Communication over Time-Varying Frequency-Selective Mobile Channels: Variable-Size Burst Construction and Adaptive Modulation

  • Francis Minhthang BuiEmail author
  • Dimitrios Hatzinakos
Open Access
Research Article
Part of the following topical collections:
  1. Reliable Communications over Rapidly Time-Varying Channels


Methods for providing good spectral efficiency, without disadvantaging the delivered quality of service (QoS), in time-varying fading channels are presented. The key idea is to allocate system resources according to the encountered channel. Two approaches are examined: variable-size burst construction, and adaptive modulation. The first approach adapts the burst size according to the channel rate of change. In doing so, the available training symbols are efficiently utilized. The second adaptation approach tracks the operating channel quality, so that the most efficient modulation mode can be invoked while guaranteeing a target QoS. It is shown that these two methods can be effectively combined in a common framework for improving system efficiency, while guaranteeing good QoS. The proposed framework is especially applicable to multistate channels, in which at least one state can be considered sufficiently slowly varying. For such environments, the obtained simulation results demonstrate improved system performance and spectral efficiency.


Fading Channel Spectral Efficiency Modulation Mode Channel Quality Adaptive Modulation 


  1. 1.
    Rappaport TS: Wireless Communications: Principles and Practice. Prentice Hall, Englewood Cliffs, NJ, USA; 1996.zbMATHGoogle Scholar
  2. 2.
    Steele R, Hanzo L: Mobile Radio Communications: Second and Third Generation Cellular and WATM Systems. John Wiley & Sons, New York, NY, USA; 1999.CrossRefGoogle Scholar
  3. 3.
    Hanzo L, Wong C, Yee M: Adaptive Wireless Transceivers: Turbo- Coded, Turbo-Equalized and Space-Time Coded TDMA, CDMA, and OFDM Systems. John Wiley & Sons, New York, NY, USA; 2002.CrossRefGoogle Scholar
  4. 4.
    Bui FM, Hatzinakos D: A receiver-based variable-size-burst equalization strategy for spectrally efficient wireless communications. IEEE Transactions on Signal Processing 2005, 53(11):4304–4314.MathSciNetCrossRefGoogle Scholar
  5. 5.
    Bui FM, Hatzinakos D: Adaptive modulation using variable-size burst for spectrally efficient interference suppression in wireless communications. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '04), November–December 2004, Dallas, Tex, USA 2: 898–902.CrossRefGoogle Scholar
  6. 6.
    Bui FM, Hatzinakos D: Identification and tracking of rapidly time-varying mobile channels for improved equalization: a basis-expansion model approach. to appear in The 5th International Symposium on Communication Systems, Network and Digital Signal Processing (CSNDSP '06), Patras, GreeceGoogle Scholar
  7. 7.
    Giannakis GB, Tepedelenlioglu C: Basis expansion models and diversity techniques for blind identification and equalization of time-varying channels. Proceedings of the IEEE 1998, 86(10):1969–1986. 10.1109/5.720248CrossRefGoogle Scholar
  8. 8.
    Barhumi I, Leus G, Moonen M: Time-varying FIR equalization for doubly selective channels. IEEE Transactions on Wireless Communications 2005, 4(1):202–214.CrossRefGoogle Scholar
  9. 9.
    Patzold M: Mobile Fading Channels. 1st edition. John Wiley & Sons, New York, NY, USA; 2002.CrossRefGoogle Scholar
  10. 10.
    Dong M, Tong L: Optimal design and placement of pilot symbols for channel estimation. IEEE Transactions on Signal Processing 2002, 50(12):3055–3069. 10.1109/TSP.2002.805504CrossRefGoogle Scholar
  11. 11.
    Haykin S: Adaptive Filter Theory. 3rd edition. Prentice Hall, Englewood Cliffs, NJ, USA; 1996.zbMATHGoogle Scholar
  12. 12.
    Floudas CA: Nonlinear and Mixed-Integer Optimization: Fundamentals and Applications. Oxford University Press, New York, NY, USA; 1995.zbMATHGoogle Scholar
  13. 13.
    Catreux S, Erceg V, Gesbert D, Heath RW: Adaptive modulation and MIMO coding for broadband wireless data networks. IEEE Communications Magazine 2002, 40(6):108–115. 10.1109/MCOM.2002.1007416CrossRefGoogle Scholar
  14. 14.
    Proakis JG: Digital Communications. 4th edition. McGraw Hill, New York, NY, USA; 2001.zbMATHGoogle Scholar
  15. 15.
    Balaban P, Salz J: Optimum diversity combining and equalization in digital data transmission with applications to cellular mobile radio. I: theoretical considerations. IEEE Transactions on Communications 1992, 40(5):885–894. 10.1109/26.141454CrossRefGoogle Scholar
  16. 16.
    Wong CH, Hanzo L: Upper-bound performance of a wide-band adaptive modem. IEEE Transactions on Communications 2000, 48(3):367–369. 10.1109/26.837037CrossRefGoogle Scholar

Copyright information

© Bui and Hatzinakos 2006

Authors and Affiliations

  1. 1.The Edward S. Rogers Sr. Department of Electrical and Computer EngineeringUniversity of TorontoTorontoCanada

Personalised recommendations