Fronthaul Compression and Beamforming Optimization for Uplink C-RAN With Intelligent Reflecting Surface-Enhanced Wireless Fronthauling

This letter studies a joint design of transmit beamforming and fronthaul compression for the uplink cloud radio access network (C-RAN) with intelligent reflecting surface (IRS) aided wireless fronthauling. In C-RAN, a number of users communicate with baseband unit (BBU) pool through multiple remote radio heads (RRH), wherein RRHs compress the received signals by Wyner-Ziv (WZ) coding and forward the quantization bits to BBU pool through wireless fronthaul link. With the goal of maximizing the uplink sum rate, an alternating algorithm is proposed for jointly optimizing the fronthaul quantization noise covariance matrices, the passive beamformer of IRS and the transmit beamformers of users and RRHs. Via numerical results, the effectiveness of the proposed joint design is verified.