This paper studies MIMO based rate adaptation (RA) in 802.11n wireless networks. Our case study shows that existing RA algorithms offer much lower throughput than even a fixed-rate scheme. The fundamental problem is that, all such algorithms are MIMO oblivious; they do not consider the characteristics of diversity-oriented, single-stream mode and the spatial multiplexing driven, double-stream mode. We propose MiRA, a novel MIMO RA scheme that zigzags between intra- and inter-mode rate options. Our experiments show that MiRA consistently outperforms three representative RA algorithms, SampleRate, RRAA and Atheros MIMO RA, in static, mobility and collision settings. Categories and Subject Descriptors C.2.1 [Computer Communication Networks]: Network Architecture and Design--Wireless communication General Terms Algorithms, Design, Experimentation, Performance Keywords MIMO, Rate Adaptation, IEEE 802.11n
Ioannis Pefkianakis, Yun Hu, Starsky H. Y. Wong, H