Decentralized antenna selection with no CSI sharing for multi-cell MU-MIMO systems

Joint User and Antenna Selection (JUAS) with global optimal solution for multi-cell Multi-User Multiple Input Multiple Output (MU-MIMO) systems needs the centralized processing and full Channel State Information (CSI) sharing that both require high capacity backhaul links. In this paper, decentralized JUAS algorithm is considered for multi-cell MU-MIMO systems with Block Diagonalization (BD) precoding. First, by introducing the eigenvalue-based lower bound on the capacity, the global optimal problem of JUAS is reformulated to a new problem that can achieve local optimum. Second, a decentralized fairness-based algorithm is proposed to select the antenna subset with no CSI sharing. Simulation results demonstrate that the proposed algorithm outperforms existing algorithms, such as capacity-based antenna selection and interference-aware user selection, with the same computation complexity. Moreover, the performance losses compared to centralized JUAS with full CSI sharing are marginal.