Spatial Multiplexing in the Multi-User MIMO Downlink Based on Signal-to-Leakage Ratios

Spatial multiplexing in the multi-user MIMO (MU-MIMO) downlink allows each user in the system to receive multiple data subchannels simultaneously using the same time and spectral resources. In this paper, we propose an iterative interference minimization scheme for the MU-MIMO downlink which is capable of transmitting multiple data subchannels to each user, at a relaxed constraint compared to schemes that rely on perfect cancellation of the co-channel interference (CCI). The proposed scheme minimizes inter-user interference (IUI) based on signal-to-leakage ratio (SLR) maximization and performs subchannel decoupling to eliminate the inter-symbol interference (ISI) within each user´s signal.