Fundamental limits of coded caching: improved delivery rate-cache capacity tradeoff
File(s)
Accepted version
Author(s)
Mohammadi Amiri, M
Gunduz, D
Type
Journal Article
Abstract
A centralized coded caching system, consisting of a server delivering N popular files, each of size F bits, to K users through an error-free shared link, is considered. It is assumed that each user is equipped with a local cache memory with capacity MF bits, and contents can be proactively cached into these caches over a low traffic period, however, without the knowledge of the user demands. During the peak traffic period, each user requests a single file from the server. The goal is to minimize the number of bits delivered by the server over the shared link, known as the delivery rate, over all user demand combinations. A novel coded caching scheme for the cache capacity of M = (N-1)/K is proposed. It is shown that the proposed scheme achieves a smaller delivery rate than the existing coded caching schemes in the literature, when K > N ≥ 3. Furthermore, we argue that the delivery rate of the proposed scheme is within a constant multiplicative factor of 2 of the optimal delivery rate for cache capacities 1/K ≤ M ≤ (N -1)/K, when K > N ≥ 3.
Date Issued
2017-02-01
Date Acceptance
2016-12-05
Citation
IEEE Transactions on Communications, 2017, 65 (2), pp.806-815
ISSN
0090-6778
Publisher
Institute of Electrical and Electronics Engineers
Start Page
806
End Page
815
Journal / Book Title
IEEE Transactions on Communications
Volume
65
Issue
2
Copyright Statement
© 2016 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.
See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Sponsor
Commission of the European Communities
Commission of the European Communities
Identifier
https://ieeexplore.ieee.org/document/7782423
Grant Number
677854
690893
Subjects
Science & Technology
Technology
Engineering, Electrical & Electronic
Telecommunications
Engineering
Centralized coded caching
network coding
proactive caching
0804 Data Format
0906 Electrical and Electronic Engineering
1005 Communications Technologies
Publication Status
Published
Date Publish Online
2016-12-13