Precoding based analog channel state information feedback scheme

By exploiting the multiple-input-multiple-output (MIMO) channel estimation and precoding, a novel analog information transmission approach is employed for the user stations (STAs) to feedback channel state information (CSI) to the access point (AP) in downlink multi-user MIMO (DL MU-MIMO) systems. Feedback frame designs and simulation results based on IEEE 802.11ac system are presented. Comparing with the existing explicit compressed feedback approach, the proposed analog CSI feedback approach achieves the same bit error rate but requires a much smaller overhead for DL MU MIMO systems.