Robust Low-Complexity MMSE Precoding Algorithm for Cloud Radio Access Networks

In this paper, the robust transceiver design for multi-cell distributed antenna systems is investigated, which is of great importance for the future mobile communication network architecture namely cloud radio access networks (C-RAN). In order to make the algorithm suitable for the multi-cell network with a large number of remote radio heads (RRHs), a low complexity robust design is proposed based on alternating direction method of multipliers (ADMM) algorithm. Exploiting the elegant properties of ADMM algorithm, the complicated relationship between the optimization objective and the per-antenna power constraint is decoupled by introducing an auxiliary variable. Meanwhile the complexity of the proposed algorithm is also significantly reduced. Finally, it is demonstrated by the simulation that the proposed robust algorithm has better performance than the existing non-robust design.