Network-MIMO cellular systems: Large-system analysis and low-overhead downlink scheduling

We consider the downlink of a multi-cell system with multi-antenna base stations and single-antenna user terminals, base station cooperation clusters, distance-dependent propagation pathloss, and general “fairness” requirements, obtained through a suitable downlink scheduling algorithm. We determine large-system expressions for the optimization of zero-forcing beamforming with joint processing from clusters of cooperating base stations. We characterize the system performance including the overhead due to training-based channel estimation, and we illuminate the tradeoff between the benefit of a larger number of cooperating antennas and the cost of estimating higher-dimensional channel vectors.