Adaptive vs. Diversity Transmission for Multiuser MISO Systems with Imperfect CSIT

Abstract— Adaptive transmission techniques including transmit beamforming, precoding, and opportunistic scheduling offer high spectral efficiency when channel state information at the transmitter (CSIT) is accurate, but suffer performance loss when the CSIT quality is poor. Diversity transmission techniques such as space-time coding and frequency interleaving, in contrast, are capable of capturing spatial and spectral diversity without CSIT, hence can provide good performance when CSIT degradation is severe. Between a pair of adaptive and diversity techniques, there exists a switching point in terms of the CSIT-quality; a CSITquality higher than this point favors the adaptive technique, but a lower CSIT-quality prefers the diversity one. This paper analyzes several adaptive and diversity schemes for a multiuser multipleinput single-output (MISO) system. Comparative performance in terms of the outage capacity is studied and the CSIT-quality switching points between adaptive and diver...

• Type: Conference
• Year: 2007
• Where: ICC
• Authors: Frederick K. H. Lee, Mai H. Vu, Arogyaswami Paulraj
• Keywords: Adaptive, Adaptive Transmissions, Communications, Diversity Schemes, ICC 2007