Date Added: Jan 2010
The authors investigate quantization and feedback of channel state information in a MultiUser (MU) Multiple Input Multiple Output (MIMO) system. Each user may receive multiple data streams. Their design minimizes the Sum Mean Squared Error (SMSE) while accounting for the imperfections in Channel State Information (CSI) at the transmitter. This paper makes three contributions: first, they provide an end-to-end SMSE transceiver design that incorporates receiver combining, feedback policy and transmit precoder design with channel uncertainty. Second, they remove dimensionality constraints on the MIMO system, for the scenario with multiple data streams per user, using a combination of Maximum Expected Signal Combining (MESC) and minimum MSE receiver. Finally, they analyze SMSE of the proposed algorithm at high Signal-to-Noise Ratio (SNR) and large number of transmit antennas.