Optimized Data Sharing in Multicell MIMO With Finite Backhaul Capacity
This paper addresses cooperation in a multicell environment where Base Stations (BSs) wish to jointly serve multiple users, under a constrained-capacity backhaul. The authors point out that for finite backhaul capacity a trade-off between sharing user data, which allows for full MIMO cooperation, and not doing so, which reduces the setup to an interference channel but also requires less overhead, emerges. They optimize this trade-off by formulating a rate splitting approach in which non-shared data (private to each transmitter) and shared data are superposed. They derive the corresponding achievable rate region and obtain the optimal beamforming design for both shared and private symbols.