NOMA Systems With Content-Centric Multicast Transmission for C-RAN

This letter considers a multicast transmission for the downlink of a cloud radio access network. In this system, each user equipment (UE) requests a file from a library and the requested files are served by a set of remote radio heads (RRHs) that are connected to a baseband processing unit (BBU) through finite-capacity fronthaul links. A conventional approach to deliver the requested files to the UEs is to perform coordinated linear precoding at the BBU and then send quantized versions of the precoded signals to the RRHs. In this letter, we investigate a non-orthogonal multiple access (NOMA) transmission scheme under the assumption that the receiving UEs perform successive interference cancellation decoding. The problem of maximizing the minimum delivery rate of the requested files subject to per-RRH fronthaul capacity and transmit power constraints is tackled. From numerical results, we validate the advantages of the proposed NOMA multicast scheme.