A Low Complexity Linear Multiuser Beamforming
Algorithm with Limited Feedback
Proc. of Conference on Information Sciences and Systems (CISS),pp. 418 - 422, March 19-21, 2008 (Princeton, NJ)
In this paper, we propose a low complexity linear transmit beamforming and receive combining vectors for the multiple-input multiple-output (MIMO) broadcast channel. We consider the specific case of transmission of a single information stream to two users with multiple antennas. Unlike past work in which an iterative algorithm is required to design the beamformers, we provide a low complexity non-iterative solution via the generalized eigenvalue decomposition for the jointly optimized transmit beamformers which works for any number of receive antennas. To enable practical implementation, a new non-uniform limited feedback algorithm is proposed that exploits the structure of the algorithm to avoid full channel quantization, and the feedback overhead is independent of the number of receive antennas. Simulation results show that the proposed method performs close to the sum capacity of the MIMO broadcast channel even with limited feedback.