Robust Transmit Beamforming Based on Probabilistic Constraint

Huiqin Du(H.Dued.ac.uk)
Pei-Jung Chung(P.Chunged.ac.uk)
Jacek Gondzio(J.Gondzioed.ac.uk)
Bernard Mulgrew(B.Mulgrewed.ac.uk)

Abstract: Transmit beamforming is a powerful technique for enhancing performance of wireless communication systems. Most existing transmit beamforming techniques require perfect channel state information at the transmitter (CSIT), which is typically not available in practice. In such situations, the design should take into account the errors in the channel estimates so that the beamformers are less sensitive to these errors. Two robust approaches are widely used. The stochastic approach optimizes the average performance of the system and assumes that the statistics, such as mean and covariance, of the errors are known. The maximin approach assumes that the errors belong to a worst-case uncertainty region and optimizes the worst-case system performance. This type of design usually leads to conservative results as the worst-case conditions may occur at a very low probability. In this paper, we propose a more flexible approach that optimizes the average performance and takes the extreme (but rare) conditions into account proportionally. Simulation results show that the proposed beamformer offers higher robustness against errors in CSIT than several state-of-the-art transmit beamformers.

Keywords: MIMO, transmit beamforming

Category 1: Applications -- Science and Engineering (Other )

Category 2: Stochastic Programming

Citation: School of Engineering and Electronics & School of Mathematics, University of Edinburgh, UK, January 2008

Download: [Postscript]

Entry Submitted: 02/07/2008
Entry Accepted: 02/07/2008
Entry Last Modified: 02/07/2008

Modify/Update this entry