On Critical Index Coding Problems

Autor: Arbabjolfaei, Fatemeh, Kim, Young-Han
Rok vydání: 2015
Předmět:
Druh dokumentu: Working Paper
Popis: The question of under what condition some side information for index coding can be removed without affecting the capacity region is studied, which was originally posed by Tahmasbi, Shahrasbi, and Gohari. To answer this question, the notion of unicycle for the side information graph is introduced and it is shown that any edge that belongs to a unicycle is critical, namely, it cannot be removed without reducing the capacity region. Although this sufficient condition for criticality is not necessary in general, a partial converse is established, which elucidates the connection between the notion of unicycle and the maximal acylic induced subgraph outer bound on the capacity region by Bar-Yossef, Birk, Jayram, and Kol.
Comment: 5 pages, accepted to 2015 IEEE Information Theory Workshop (ITW), Jeju Island, Korea
Databáze: arXiv