MISO Cache-Aided Communication with Reduced Subpacketization

Abstract

We present a novel low complexity scheme for cache aided communication, where a multi-antenna base station serves multiple single-antenna mobiles. The scheme is based on transmission of coded messages to disjoint groups of users simultaneously. Compared to the state-of-the-art, the proposed scheme significantly reduces the transmission and decoding complexity. Furthermore, it substantially relaxes the subpacketization level, and involves a transmission of much smaller number of packets in each time block. The proposed scheme achieves the same degrees of freedom (DoF) as the best known scheme, but, it suffers from a performance degradation of about 1.5dB due to a loss of diversity. Nevertheless, the loss is acceptable as the reduction in complexity allows a practical implementation of this scheme even for a large number of users.