Study on Reference Signals and Control Signaling for Downlink MU-MIMO in LTE-Advanced

摘要

Multi-user MIMO (MU-MIMO) is identified as a key technique for Long Term Evolution Advanced (LTE-A) to reach the performance requirements. In this paper, we present our study on the MU-MIMO design issues in LTE-A that are relevant to standardization such as MU-MIMO transparency, and demodulation reference signal (DM-RS) configuration. Besides qualitative analysis from various system impacts including signaling overhead, scheduling flexibility and channel estimation accuracy, numerical results are provided by both link-level and system-level simulations as well. Based on the study, we propose to support transparent MU-MIMO with quasi-orthogonal DM-RS configuration in LTE-A.