Maximizing Expected Achievable Rates for Block-Fading Buffer-Aided Relay Channels

Mohammad Shaqfeh, Ammar Zafar, Hussein Alnuweiri, Mohamed Slim Alouini

Research output: Contribution to journalArticle

7 Citations (Scopus)


In this paper, the long-term average achievable rate over block-fading buffer-aided relay channels is maximized using a hybrid scheme that combines three essential transmission strategies, which are decode-and-forward, compress-and-forward, and direct transmission. The proposed hybrid scheme is dynamically adapted based on the channel state information. The integration and optimization of these three strategies provide a more generic and fundamental solution and give better achievable rates than the known schemes in the literature. Despite the large number of optimization variables, the proposed hybrid scheme can be optimized using simple closed-form formulas that are easy to apply in practical relay systems. This includes adjusting the transmission rate and compression when compress-and-forward is the selected strategy based on the channel conditions. Furthermore, in this paper, the hybrid scheme is applied to three different models of the Gaussian block-fading buffer-aided relay channels, depending on whether the relay is half or full duplex and whether the source and the relay have orthogonal or non-orthogonal channel access. Several numerical examples are provided to demonstrate the achievable rate results and compare them to the upper bounds of the ergodic capacity for each one of the three channel models under consideration.

Original languageEnglish
Article number7478633
Pages (from-to)5919-5931
Number of pages13
JournalIEEE Transactions on Wireless Communications
Issue number9
Publication statusPublished - 1 Sep 2016



  • block-fading
  • buffer-aided relaying
  • compress-and-forward
  • decode-and-forward
  • Relay channel

ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics

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