Linear transceiver design in a multiuser MIMO system with quantized channel state information

We design an end-to-end linear transceiver in the downlink of a multi-user multiple-input multiple-output (MIMO) system with multiple data streams per user and quantized channel state information at the transmitter. We minimize the sum mean squared error (SMSE) under a sum power constraint with quantization based on the mean squared inner product. We make three contributions: (i) we remove dimensionality constraints on the MIMO configuration and the resulting feedback overhead scales linearly with the number of data streams; (ii) we use the combination of eigenmode combining and minimum mean square error receiver that makes user´s feedback mutually independent; (iii) we analyze SMSE at high signal-to-noise ratio and large number of transmit antennas and derive an approximate SMSE floor.