Cache-Aided Interference Management in Wireless Cellular Networks

Abstract

We consider the problem of interference management in wireless cellular networks with caches at both base stations and receivers, and we characterize the degrees of freedom (DoFs) per cell to within an additive gap of (1/3) and a multiplicative gap of 2 for all system parameters, under one-shot linear schemes. Our result indicates that the one-shot linear DoF per cell scales linearly with the total amount of cache available in the cell, i.e., the sum of the caches at the central base station and all the receivers within the cell, resembling a similar phenomenon previously observed for the case of fully connected wireless networks. To establish the result, we propose a decentralized and randomized cache placement and a delivery scheme, which, on one hand, utilizes the overlap of contents at the base station caches to zero-force part of their outgoing interference and, on the other hand, uses the receiver cache contents to create coded multicasting opportunities, so that the receivers can eliminate the remaining interference due to undesired packets. We also provide a converse argument, which shows that our achievable one-shot linear DoF per cell is within a constant additive gap of (1/3) and a multiplicative gap of 2 of its optimum.