Communication over fading channels with delay constraints

Randall A. Berry*, Robert G. Gallager

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

576 Scopus citations


We consider a user communicating over a fading channel with perfect channel state information. Data is assumed to arrive from some higher layer application and is stored in a buffer until it is transmitted. We study adapting the user's transmission rate and power based on the channel state information as well as the buffer occupancy; the objectives are to regulate both the long-term average transmission power and the average buffer delay incurred by the traffic. Two models for this situation are discussed; one corresponding to fixed-length/variable-rate codewords and one corresponding to variable-length codewords. The tradeoff between the average delay and the average transmission power required for reliable communication is analyzed. A dynamic programming formulation is given to find all Pareto optimal power/delay operating points. We then quantify the behavior of this tradeoff in the regime of asymptotically large delay. In this regime, we characterize simple buffer control policies which exhibit optimal characteristics. Connections to the delay-limited capacity and the expected capacity of fading channels are also discussed.

Original languageEnglish (US)
Pages (from-to)1135-1149
Number of pages15
JournalIEEE Transactions on Information Theory
Issue number5
StatePublished - May 2002


  • Fading channels
  • Power control
  • Resource allocation
  • Wireless networks

ASJC Scopus subject areas

  • Information Systems
  • Computer Science Applications
  • Library and Information Sciences

Fingerprint Dive into the research topics of 'Communication over fading channels with delay constraints'. Together they form a unique fingerprint.

Cite this