User Selection for Multiple-Antenna Broadcast Channel with Zero-Forcing Beamforming

Abstract—This paper investigates the zero-forcing (ZF) beamforming transmit strategy in the multiple-antenna multiuser downlink systems. We consider the case of mobile users equipped with multiple antennas. Although the capacity of such systems can be achieved by dirty paper coding (DPC), DPC is extremely difficult and challenging to implement. Thus, simple but suboptimal linear beamforming techniques like ZF beamforming can be deployed. However, the number of users that can be served using this strategy is limited by the number of transmit antennas at the base station. The solution for this limitation is user selection (scheduling), which also exploits multiuser diversity. Therefore, user selection can be used to enhance the throughput of the system. Recently, it has been shown that ZF beamforming strategy with user selection is asymptotically optimal for a large number of users. In this paper, a semi-orthogonal user selection (SUS) algorithm is extended to the system with multiple...

• Type: Conference
• Year: 2008
• Where: GLOBECOM
• Authors: Saeed Kaviani, Witold A. Krzymien
• Keywords: Beamforming, Communications, GLOBECOM 2008, Optimal Zf, User Selection