Cooperative Beamforming for Wireless Ad Hoc Networks

—Via collaborative beamforming, nodes in a wireless network are able to transmit a common message over long distances in an energy efficient fashion. However, the process of making available the same message to all collaborating nodes introduces delays. In this paper, a MAC-PHY cross-layer scheme is proposed that enables collaborative beamforming at significantly reduced collaboration overhead. It consists of two phases. In the first phase, nodes transmit locally in a random access time-slotted fashion. Simultaneous transmissions from multiple source nodes are viewed as linear mixtures of all transmitted packets. In the second phase, a set of collaborating nodes, acting as a distributed antenna system, beamform the received analog waveform to one or more faraway destinations. This step requires multiplication of the received analog waveform by a complex weight, which is independently computed by each cooperating node, and which allows packets bound to the same destination to add c...

• Type: Conference
• Year: 2007
• Where: GLOBECOM
• Authors: Lun Dong, Athina P. Petropulu, H. Vincent Poor
• Keywords: Analog Waveform, Communications, Enables Collaborative Beamforming, GLOBECOM 2007, Multiple Source Nodes