An interference-robust channel estimation method for MU-MIMO transmission in LTE-Advanced system

To support a transparent multi-user multiple-input multiple output (MU-MIMO) transmission, the orthogonality between co-scheduled layers is not perfectly guaranteed in the long term evolution (LTE)-Advanced system. In this case, however, significant performance degradation in channel estimation can occur due to the interference from transmit signals for co-scheduled users. To overcome this problem, the proposed method partially estimates and eliminates the interference using simple matrix operations. After the partial interference cancellation, we apply a two-dimensional minimum mean squared error (2-D MMSE) channel estimation scheme with an adaptive weighting method considering the remaining interference and noise.