A Turbo-Like Iterative Decoding Algorithm for Network Coded HARQ
Konferenz: SCC 2013 - 9th International ITG Conference on Systems, Communication and Coding
21.01.2013 - 24.01.2013 in München, Deutschland
Tagungsband: SCC 2013
Seiten: 6Sprache: EnglischTyp: PDFPersönliche VDE-Mitglieder erhalten auf diesen Artikel 10% Rabatt
Lang, Yidong; Wübben, Dirk; Dekorsy, Armin (University of Bremen, Bremen, Germany)
Braun, Volker; Doetsch, Uwe (Alcatel-Lucent Bell Labs, Stuttgart, Germany)
This paper proposes a turbo-like decoding algorithm for network coded HARQ (NC-HARQ) retransmission scheme. Instead of retransmission erroneous packets individually, we send a network coded packet formed by XOR of two incorrectly received packets in the NC-HARQ retransmission. With respect to the two initial packets and one network coded packet, this retransmission scheme can be viewed as a product code based on the Turbo coding principle. We develop an iterative decoding algorithm for the proposed NC-HARQ scheme. The algorithm uses the log-likelihood ratios generated by decoding any two packets to calculate a priori information for the third one. This approach is applicable for both Chase Combing (CC) and Incremental Redundancy (IR). Furthermore, a link adaptation algorithm is investigated for the proposed network coded HARQ scheme. LTE link-level simulations confirm the throughput enhancement by the proposed scheme compared to common HARQ transmission. Index Terms — Network coding, HARQ, iterative decoding, link adaptation.