Practical scheme for MISO Cache-Aided Communication

Abstract

Multi-antenna cache aided communication schemes suffer from high implementation complexity, due to the need of dividing each file into many small segments (known as the sub-packetization problem). In a recent publication, we introduced a low complexity scheme which significantly reduces the complexity, but works only for specific combinations of system parameters, including memory size, number of users, and number of antennas at the base station. In this work we present a novel extension that achieves the same number of degrees of freedom (DoF) at low complexity for any system parameter. In this scheme, a base station with multiple antennas serves multiple single-antenna mobiles, while using a small cache memory at each mobile to boost the network throughput. We also present a greedy scheduling algorithm, and show that it reaches nearly 100% of efficiency for a large number of users. The significant reduction in complexity and the general applicability make this scheme suitable for practical implementation.