ADAM: An adaptive beamforming system for multicasting in wireless LANs

—We present the design and implementation of ADAM, the first adaptive beamforming based multicast system and experimental framework for indoor wireless environments. ADAM addresses the joint problem of adaptive beamformer design at the PHY layer and client scheduling at the MAC layer by proposing efficient algorithms that are amenable to practical implementation. ADAM is implemented on an FPGA platform and its performance is compared against that of omni-directional and switched beamforming based multicast. Our experimental results reveal that (i) switched multicast beamforming has limited gains in indoor multi-path environments, whose deficiencies can be effectively overcome by ADAM to yield an average gain of three-fold; (ii) the higher the dynamic range of the discrete transmission rates employed by the MAC hardware, the higher the gains in ADAM’s performance, yielding upto nine-fold improvement over omni with the 802.11 rate table; and (iii) finally, ADAM’s performance is...

• Type: Journal
• Year: 2012
• Where: INFOCOM
• Authors: Ehsan Aryafar, Mohammad Ali Khojastepour, Karthikeyan Sundaresan, Sampath Rangarajan, Edward W. Knightly
• Keywords: Adaptive Beamforming, Coherence Time, Communications, INFOCOM 2012, Wireless Environments