Semi-orthogonal precoder design with vector quantized channel information feedback

This paper deals with the sum-rate performance in the broadcasting channel of a decentralized multiuser multi-antenna system. With the assumption of limited channel state information available at the base station and a large number of single antenna decentralized users in a cell, we propose a Semi-orthogonal precoding method with a total feedback rate constraint, and analyze its the sum-rate performance. A lower bound to the sum-rate of broadcast channels with quantized channel direction information and channel quality information is obtained. It can be used to evaluate the performance of broadcast channels with finite-rate feedback of channel state information and semi-orthogonal user selection. Numerical examples show that our analytical results agree with Monte Carlo simulations.