R2D2: regulating beam shape and rate as directionality meets diversity

We design, implement, and evaluate a vehicular communication system that improves uplink connectivity through multi-lobe beam pattern switching on a smart antenna. Directionality and base station-diversity are two well-known, independently developed mechanisms for improving the uplink connectivity of mobile clients. In this paper, we highlight that a system combining both mechanisms can achieve significant improvement in performance with multi-lobe beams that strike a tradeoff between directionality and diversity. This is in contrast to the mere steering of narrow beams used in conventional smart antenna systems. For tractability at vehicular speeds, our R2D2 system searches through a limited set of beam patterns with different numbers of lobes, and includes a two-stage algorithm that uses both runtime adaptation and cached candidate patterns. We design and evaluate several variants of run-time adaptation that tune the number and angle of lobes in the beam, and the bit rate. The desig...

• Type: Conference
• Year: 2009
• Where: MOBISYS
• Authors: Kishore Ramachandran, Ravi Kokku, Karthikeyan Sundaresan, Marco Gruteser, Sampath Rangarajan
• Keywords: MOBISYS 2009, Smart Antenna, Uplink Connectivity, Uplink Throughput Increase, Wireless Networks