The asymptotic optimality of a jointly optimized linear multiuser beamforming system with two transmit and many receive antennas for the fading multiple-input multiple-output (MIMO) Gaussian broadcast channel is investigated. We derive the asymptotic sum capacity of the independent and identically-distributed (i.i.d.) MIMO broadcast channel and the asymptotic sum rate of a linear multiuser beamforming system with respect to the number of receive antennas per user, where two users are served with a zero inter-user interference constraint. Based on this result, we show that linear multiuser beamforming with many receive antennas can asymptotically achieve the sum capacity of the two-user i.i.d. MIMO broadcast channel even without opportunistic scheduling gain. Numerical results confirm that as the number of receive antennas increases the sum rate of linear multiuser beamforming system converges to the sum capacity.
Bibliographical noteFunding Information:
Manuscript received June 16, 2008; revised October 06, 2008. Current version published January 09, 2009. This work was supported by Samsung Electronics. The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Martin Haardt. C.-B. Chae is with the School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138 USA (e-mail: email@example.com). R. W. Heath, Jr. is with the Wireless Networking and Communications Group (WNCG), Department of Electrical and Computer Engineering, The University of Texas, Austin, TX 78712 USA (e-mail: firstname.lastname@example.org). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/LSP.2008.2008937
All Science Journal Classification (ASJC) codes
- Signal Processing
- Electrical and Electronic Engineering
- Applied Mathematics