Asymptotic Analysis of Distributed Multi-Cell Beamforming

The downlink of a cellular system has been a widely researched topic in the past decade both in the isolated single cell processing scenario and the joint multi-cell processing scenario. It has been well established that significant performance improvements can be obtained if the Base Stations (BSs) coordinate by Channel State Information (CSI) and user data sharing via high-capacity backhaul links (network MIMO (Multiple Input Multiple Output)) and jointly serve the User Terminals (UTs). However, as the number of antennas on the BS, the number of UTs and the number of coordinating cells grow large; this approach quickly becomes impractical due to the heavy backhaul requirement.