A New Converse Bound for Coded Caching

An information-theoretic lower bound is developed for the caching system studied by Maddah-Ali and Niesen. By comparing the proposed lower bound with the decentralized coded caching scheme of Maddah-Ali and Niesen, the optimal memory--rate tradeoff is characterized to within a multiplicative gap of 4.7 for the worst case, improving the previous analytical gap of 12. Furthermore, for the case when users' requests follow the uniform distribution, the multiplicative gap is tightened to 4.7, improving the previous analytical gap of 72. As an independent result of interest, for the single-user average case in which the user requests multiple files, it is proved that caching the most requested files is optimal.


Published in:
Proceedings of the 2016 Information Theory and Applications Workshop (ITA)
Presented at:
2016 Information Theory and Applications Workshop (ITA), San Diego, CA, USA, January 31-February 5, 2016
Year:
2016
Laboratories:




 Record created 2016-02-02, last modified 2018-03-17

n/a:
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)