An Experimental Evaluation of Rate Adaptation for Multi-Antenna Systems

—Increasingly wireless networks use multi-antenna nodes as in IEEE 802.11n and 802.16. The Physical layer (PHY) in such systems may use the antennas to provide multiple streams of data (spatial multiplexing) or to increase the robustness of fewer streams. These physical layers also provide support for sending packets at different rates by changing the modulation and coding of transmissions. Rate adaptation is the problem of choosing the best transmission mode for the current channel and in these systems requires choosing both the level of spatial multiplexing and the modulation and coding. Hydra is an experimental wireless network node prototype in which both the MAC and PHY are highly programmable. Hydra’s PHY is essentially the 802.11n PHY, and currently supports two antennas and the same modulations and codings as 802.11n. Because of limitations of our hardware platform, the actual rates are a factor of 10 smaller than 802.11n. The MAC is essentially the 802.11 MAC with extensio...

• Type: Conference
• Year: 2009
• Where: INFOCOM
• Authors: Wonsoo Kim, O. Khan, Kien T. Truong, Soon-Hyeok Choi, Robert Grant, Hyrum K. Wright, Ketan Mandke, Robert C. Daniels, Robert W. Heath Jr., Scott Nettles
• Keywords: Communications, INFOCOM 2009, Multiple Spatial Streams, Rate Adaptation, Spatial Multiplexing