2017/05/12 by Parisa Hassanzadeh, Hassanzadeh, Parisa, Antonia M. Tulino +5
Computer Science · Engineering · #Caching and Content Delivery #Cooperative Communication and Network Coding #Advanced Wireless Network Optimization
paper · pdf · doi:10.48550/arxiv.1705.04616
This paper studies the fundamental limits of caching in a network with two\nreceivers and two files generated by a two-component discrete memoryless source\nwith arbitrary joint distribution. Each receiver is equipped with a cache of\nequal capacity, and the requested files are delivered over a shared error-free\nbroadcast link. First, a lower bound on the optimal peak rate-memory trade-off\nis provided. Then, in order to leverage the correlation among the library files\nto alleviate the load over the shared link, a two-step correlation-aware\ncache-aided coded multicast (CACM) scheme is proposed. The first step uses\nGray-Wyner source coding to represent the library via one common and two\nprivate descriptions, such that a second correlation-unaware multiple-request\nCACM step can exploit the additional coded multicast opportunities that arise.\nIt is shown that the rate achieved by the proposed two-step scheme matches the\nlower bound for a significant memory regime and it is within half of the\nconditional entropy for all other memory values.\n