R Bits User Selection Switch Feedback for Zero Forcing MU-MIMO Based on Low Rate Codebook
Channel feedback for Multi-User (MU)-Multiple-Input Multiple-Output (MIMO) has been widely studied and some results have been got with random vector quantization scheme. However, while the low rate fixed codebook feedbacks are adopted, the performance of Zero Forcing (ZF) MU-MIMO will decrease as the unpredictable inter-user interference is introduced because of quantized Channel State Information (CSI). To decrease inter-user interference in low rate fixed codebook feedback, an enhanced User Selection Switch (USS) feedback scheme for ZF MU-MIMO is proposed in this paper. In USS feedback, the extra USS information is added after quantized CSI and received signal-to-noise ratio feedback.