Index coding - An interference alignment perspective

Hamed Maleki, Viveck R. Cadambe, Syed A. Jafar

    Research output: Contribution to journalArticlepeer-review

    92 Scopus citations

    Abstract

    The index coding problem is studied from an interference alignment perspective providing new results as well as new insights into, and generalizations of, previously known results. An equivalence is established between the capacity of multiple unicast index coding (where each message is desired by exactly one receiver), and groupcast index coding (where a message can be desired by multiple receivers), which settles the heretofore open question of insufficiency of linear codes for the multiple unicast index coding problem by equivalence with groupcast settings, where this question has previously been answered. Necessary and sufficient conditions for the achievability of rate half per message in the index coding problem are shown to be a natural consequence of interference alignment constraints, and generalizations to feasibility of rate 1/(L+1)per message when each destination desires at least L messages, are similarly obtained. Finally, capacity optimal solutions are presented to a series of symmetric index coding problems inspired by the local connectivity and local interference characteristics of wireless networks. The solutions are based on vector linear coding.

    Original languageEnglish (US)
    Article number6855359
    Pages (from-to)5402-5432
    Number of pages31
    JournalIEEE Transactions on Information Theory
    Volume60
    Issue number9
    DOIs
    StatePublished - Sep 2014

    All Science Journal Classification (ASJC) codes

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

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