A rateless coded protocol for half-duplex wireless relay channels

Momin Uppal, Guosen Yue, Xiaodong Wang, Zixiang Xiong

Research output: Contribution to journalArticleResearchpeer-review

20 Citations (Scopus)


We propose a rateless coded protocol for a half-duplex wireless relay channel where all links experience independent quasi-static Rayleigh fading and the instantaneous channel realizations are unavailable at the transmitters. We assume that the network does not have a stringent delay constraint-thus the source and/or the relay continue transmitting until the destination acknowledges successful decoding. We identify rateless coded relaying as the natural choice, where each transmission from the source and/or the relay adds incremental redundancy to help the destination recover the original message. Our proposed protocol utilizes, in conjunction with rateless coding, a combination of the two popular relay cooperation schemes, namely decode-forward and compress-forward. Assuming very limited feedback from the destination, we derive the theoretical performance bounds specifically with binary phase-shift keying. We then implement the rateless coded relaying protocol using Raptor codes. The degree profiles for the Raptor codes are designed to maximize the average throughput-with the design formulated as a convex optimization problem. Using discretized density evolution for asymptotically large block lengths, the optimized codes lose approximately 5% in performance from the theoretical limit, whereas with practical finite block lengths, the performance loss is approximately 9%. 

Original languageEnglish
Article number5604326
Pages (from-to)209-222
Number of pages14
JournalIEEE Transactions on Signal Processing
Issue number1
Publication statusPublished - Jan 2011
Externally publishedYes


  • Compress-forward and rateless coding
  • Decode-forward
  • Half-duplex relay
  • A rateless coded protocol for half-duplex wireless relay channels

    Uppal, M., Yue, G., Wang, X. & Xiong, Z., 2010, 2010 IEEE International Symposium on Information Theory, ISIT 2010 - Proceedings. p. 953-957 5 p. 5513439

    Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

    4 Citations (Scopus)

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