2022/01/27 by Ting Yang, Kai Wan, Yang, Ting +5 · 2 citations
Computer Science · Engineering · #Caching and Content Delivery #Cooperative Communication and Network Coding #Energy Harvesting in Wireless Networks #FOS: Computer and information sciences #Information Theory (cs.IT)
paper · pdf · doi:10.48550/arxiv.2201.11462
openalex publication_date 2022/01/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider the cache-aided multiple-input single-output (MISO) broadcast channel, which consists of a server with L antennas and K single-antenna users, where the server contains N files of equal length and each user is equipped with a local cache of size M files. Each user requests an arbitrary file from library. The objective is to design a coded caching scheme based on uncoded placement and one-shot linear delivery, to achieve the maximum sum Degree-of-Freedom (sum-DoF) with low subpacketization. It was shown in the literature that under the constraint of uncoded placement and one-shot linear delivery, the optimal sum-DoF is L+(KM)/(N). However, previously proposed schemes for this setting incurred either an exponential subpacketization order in K, or required specific conditions in the system parameters L, K, M and N. In this paper, we propose a new combinatorial structure called multiple-antenna placement delivery array (MAPDA). Based on MAPDA and Latin square, the first proposed scheme achieves the optimal sum-DoF L+(KM)/(N) with the subpacketization of K when (KM)/(N)+L=K. Subsequently, for the general case we propose a transformation approach to construct an MAPDA from any g-regular PDA (a class of PDA where each integer in the array occurs g times) for the original shared-link coded caching problem. When the original PDA corresponds to the Maddah-Ali and Niesen coded caching scheme, the resulting scheme under the combinatorial structure of MAPDA can achieve the optimal sum-DoF L+(KM)/(N) with reduced subpacketization with respect to the existing schemes. The work can be extended to the multiple independent single-antenna transmitters (servers) corresponding to the cache-aided interference channel proposed by Naderializadeh et al. and the scenario of transmitters equipped with multiple antennas.