Cache-Aided Non-Orthogonal Multiple Access Over Fading Channels in Downlink Cellular Networks

Abstract

Integration of caching and non-orthogonal multiple access (NOMA) is envisioned to enhance the spectral efficiency in cellular networks. In this paper, we study the performance of cache-aided NOMA over various fading downlink channels, namely Weibull, Nakagami and Rician channels. In particular, we consider a cache-equipped two-user cellular network and propose an optimization problem to find the optimal power control policy such that the probability of successful decoding of files at the network is maximized, for each of the fading models. Through extensive Monte Carlo simulations and numerical results, we validate the analytically derived expressions for optimal power allocation, and show that the cache-aided NOMA scheme outperforms both conventional NOMA and cache-aided orthogonal multiple access schemes, in terms of probability of successful decoding of files at each user.