Distributed Beamforming Using a Scattering Network

Novel beam-forming methodology is proposedthat employs passive RF devices in order to enhance thereceived signal. This paper demonstrates the feasibility of suchbeamforming and the realization methodology for a randomlyplaced set of passive devices. Typically, a beamforming isrealized by employing an antenna array at a receiver ortransmitter. The signals from antenna elements are processedin order to eliminate negative effects of multipath fading. Incontrast, the proposed methodology employs spatiallydistributed, passive scattering devices located betweentransmitter and receiver in order to realize the beamforming.The proposed scheme assumes that these RF devices maychange their impedance to increase or reduce scattering effect.The paper demonstrates that signal strength at the receiver canbe increased by carefully selecting the devices that shouldscatter the RF signal. The theoretical limits of such scheme areanalyzed mathematically and in simulations. The paperpresents two approaches that learn the best set of scatteringnodes and utilizes it to realize the beamforming.