Sciweavers

TSP
2010

Optimality of beamforming for MIMO multiple access channels via virtual representation

12 years 10 months ago
Optimality of beamforming for MIMO multiple access channels via virtual representation
In this paper, we consider the optimality of beamforming for achieving the ergodic capacity of multiple-input multiple-output (MIMO) multiple access channel (MAC) via virtual representation (VR) model. We assume that the receiver knows the channel state information (CSI) perfectly but that the transmitter knows only partial CSI, i.e., the channel statistics. For the single-user case, we prove that the capacity-achieving beamforming angle (c.b.a.) is unique, and there exists a signal-to-noise ratio (SNR) threshold below which beamforming is optimal and above which beamforming is strictly suboptimal. For the multi-user case, we show that the c.b.a is not unique and we obtain explicit conditions that determine the beamforming angles for a special class of correlated MAC-VR models. Under mild conditions, we show that a large class of power allocation schemes can achieve the sum-capacity within a constant as the number of users in the system becomes large. The beamforming scheme, in particu...
Hong Wan, Rong-Rong Chen, Yingbin Liang
Added 22 May 2011
Updated 22 May 2011
Type Journal
Year 2010
Where TSP
Authors Hong Wan, Rong-Rong Chen, Yingbin Liang
Comments (0)