New Beamforming Schemes with Optimum Receive Combining for Multiuser MIMO systems

— In this paper, we present a new beamforming scheme for a downlink of multiuser multiple-input multipleoutput (MIMO) communication systems. Recently, a blockdiagonalization (BD) algorithm has been proposed for the multiuser MIMO downlink where both a base station and each user have multiple antennas. However, the BD algorithm is not efficient when the number of supported streams per user is smaller than that of receive antennas. Since the BD method utilizes the nullspace based on the channel matrix without considering the receive combining, the degree of freedom for beamforming cannot be fully exploited at the transmitter. In this paper, we optimize the receive beamforming vector under a zero forcing (ZF) constraint, where all inter-user interference is driven to zero. We propose an efficient algorithm to find the optimum receive vector by an iterative procedure. The proposed algorithm requires two phase values feedforward information for the receive combining vector. Also, we pr...

• Type: Conference
• Year: 2008
• Where: ICC
• Authors: Sang-Rim Lee, Seokhwan Park, Sung Hyun Moon, Inkyu Lee
• Keywords: Algorithm, BD Algorithm, Beamforming, Communications, ICC 2008