A novel centralized coded caching scheme with coded prefetching

For the caching problem, when the number of files is no larger than that of users, the best known rate-memory region is achieved by memory sharing between the rate-memory pairs obtained by three schemes: the scheme proposed by Yu et al., the scheme proposed by Gomez-Vilardebo, and the scheme proposed by Tian and Chen. While the first two schemes operate on the binary field, the Tian-Chen scheme makes use of a finite field of order 2 m with, in some situations, m ≥ K log 2 (N) for a caching systems with K users and N files. The practical implications of this increase in the size of the field are equivalent to an increase, by a factor of m, in the number of subfile partitions required. We propose a novel caching scheme that approaches the rate-memory region achieved by the Tian-Chen scheme as the number of users in the system increases, which only requires a field of order 2 2 .Grant numbers : This work was supported in part by the Catalan Government under Grant SGR2017-1479, and in part by the Spanish Government under Grant TEC2013-44591-P (INTENSYV). © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works