Full-Duplex Relaying With Partial CSI in Cloud Radio Access Networks

Abstract

This paper proposes a full-duplex decode-and-forward relaying scheme with partial channel state information (CSI) in the cloud radio access network (C-RAN), which is re-ferred to as cloud full-duplex relaying (CFDR). Two remote radio heads (RRHs) acting as virtual full-duplex relays are connected to a baseband unit (BBU). A RRH receives the superposition of the differential binary phase-shift keying symbols from the user and another RRH. Owing to cooperative processing based on cloud capabilities, the interference from another RRH can be eliminated at BBU through the designed non-coherent maximum likelihood decoding method, in which only partial CSI, i.e., channel distribution information is required. The closed-form end-to-end bit error rate (BER) of CFDR is derived, which is validated by the simulation. The simulation results show that CFDR doubles the upper bound of the spectral efficiency and reduces the delay by half compared with half-duplex relaying in C-RAN.