MIMO Channels with Limited Rate Feedback and RVQ

The capacity increases promised by multi-input multi-output (MIMO) systems usually come with requirements in regard to channel knowledge. We study the capacity of a MIMO scheme with perfect channel state information (CSI) at the receiver side where the transmitter has only a quantized version of the CSI due to a limited rate feedback channel. Random vector quantization is investigated along with a reduced number of precoders. It is found out that capacity losses are quite tolerable even in the case of small number of bits per quantized precoder.