Collaborative Beamforming for Distributed Wireless Ad Hoc Sensor Networks

TL;DR

This paper analyzes the statistical properties of collaborative beamforming in wireless ad hoc sensor networks, deriving the beampattern distribution and examining effects of node distribution, phase jitter, and location errors.

Contribution

It introduces a theoretical framework for understanding the beampattern of randomly distributed sensor nodes and evaluates the impact of practical imperfections.

Findings

Directivity approaches the number of sensors N with sparse distribution.

Distribution of sidelobe peaks characterized.

Phase jitter and location errors affect beamforming performance.

Abstract

The performance of collaborative beamforming is analyzed using the theory of random arrays. The statistical average and distribution of the beampattern of randomly generated phased arrays is derived in the framework of wireless ad hoc sensor networks. Each sensor node is assumed to have a single isotropic antenna and nodes in the cluster collaboratively transmit the signal such that the signal in the target direction is coherently added in the far- eld region. It is shown that with N sensor nodes uniformly distributed over a disk, the directivity can approach N, provided that the nodes are located sparsely enough. The distribution of the maximum sidelobe peak is also studied. With the application to ad hoc networks in mind, two scenarios, closed-loop and open-loop, are considered. Associated with these scenarios, the effects of phase jitter and location estimation errors on the average beampattern are also analyzed.