Compressed Cooperative Reception for the Uplink of C-RAN With Wireless Fronthaul

This work deals with a joint design of radio access and fronthaul links for the uplink of cloud radio access network (C-RAN) equipped with wireless fronthaul link. A conventional uplink system based on per-cell decode-and-forward (DF) relaying, in which the message sent by each user equipment (UE) is decoded by the closest remote radio head (RRH) and forwarded to a baseband processing unit (BBU) via wireless fronthaul link, is first reviewed. Since decoding at each RRH might be affected by the interference signals of the other UEs, we present a compress-and-forward (CF) based cooperative reception scheme whereby each RRH quantizes and compresses its received signal and transmits the quantization output to the BBU through the fronthaul link. For the both approaches based on the DF and CF relaying, we tackle the problem of maximizing the sum-rate of the UEs subject to the per-UE and per-RRH power constraints. Linklevel simulation results are reported that validate the advantages of the CF-based cooperative scheme compared to the DF-based per-cell reception scheme.