Quantized Feedback Design for MIMO Broadcast Channels

Low-rate feedback design for multiple-input multiple-output broadcast channels is studied under a vector quantization framework. Iterative algorithms are proposed to design the partial feedback link, the scheduler, and the linear precoding codebook. It is demonstrated that the gain due to multi-user diversity can be significant even with heavily quantized channel state information at the transmitter. Our results highlight the potential of multi-user diversity, even with simple schemes and extremely-low-rate feedback.