Low Complexity Receivers for Massive MIMO Cloud Radio Access Systems

In this work, we consider uplink receiver design for cloud radio access networks (C-RANs) employing massive multi-input multi-ouput (MIMO). Considering joint detection at the base band unit pool for user ends from multiple remote radio heads, we propose a low complexity C-RAN version of the Vertical Bell Laboratories Layered Space-Time (C-RAN-BLAST). The C-RAN versions of the zero-forcing (ZF) and minimum mean-squared error (MMSE) receivers are employed for comparison. The C-RAN-BLAST offers similar performance to the ZF receiver, at much lower complexity. The MMSE receiver performs somewhat better, at the cost of higher complexity, and requiring more detailed channel state information.