Achievable rate optimization for coordinated multi-point transmission (CoMP) in cloud-based RAN architecture

In this paper, we consider Coordinated Multi-Point (CoMP) in a cloud-based radio access network (RAN), where each coordinating access point compresses its observation using distributed Wyner-Ziv compression and forwards the compressed signal to the receiving processing unit. We map this architecture to the multiple-relay compress-and-forward (CF) problem, derive the achievable rate of such a system and then show that the achievable rate can be maximized by optimizing the distributed compression rate at each individual coordinating point in a joint manner. An iterative optimization algorithm is proposed and numerical results indicate that compared with other coordinating schemes, when the channel between the coordinating points and the processing unit is strong, using distributed compression can effectively improve the spectrum efficiency.