Opportunistic Collaborative Beamforming with One-Bit Feedback

TL;DR

This paper introduces an energy-efficient opportunistic collaborative beamforming scheme for sensor networks that uses only one-bit feedback per node, enabling scalable and effective signal power enhancement without local phase precompensation.

Contribution

It proposes a novel beamforming method that selects node subsets opportunistically with minimal feedback, improving scalability and energy efficiency in sensor networks.

Findings

Signal power scales linearly with the number of nodes.

Low-complexity node selection algorithms are effective.

Simulation confirms the scheme's effectiveness.

Abstract

An energy-efficient opportunistic collaborative beamformer with one-bit feedback is proposed for ad hoc sensor networks over Rayleigh fading channels. In contrast to conventional collaborative beamforming schemes in which each source node uses channel state information to correct its local carrier offset and channel phase, the proposed beamforming scheme opportunistically selects a subset of source nodes whose received signals combine in a quasi-coherent manner at the intended receiver. No local phase-precompensation is performed by the nodes in the opportunistic collaborative beamformer. As a result, each node requires only one-bit of feedback from the destination in order to determine if it should or shouldn't participate in the collaborative beamformer. Theoretical analysis shows that the received signal power obtained with the proposed beamforming scheme scales linearly with the number of available source nodes. Since the the optimal node selection rule requires an exhaustive search over all possible subsets of source nodes, two low-complexity selection algorithms are developed. Simulation results confirm the effectiveness of opportunistic collaborative beamforming with the low-complexity selection algorithms.