ChordMics: Acoustic Signal Purification with Distributed Microphones

TL;DR

ChordMics is a distributed beamforming system that uses spatial diversity of microphones to extract signals from arbitrary points, outperforming centralized systems with up to 15dB SINR gain in noisy environments.

Contribution

It introduces ChordMics, a novel distributed microphone system that overcomes synchronization challenges to improve acoustic signal extraction in noisy settings.

Findings

Achieves up to 15dB SINR improvement over centralized systems.

Effective in both line-of-sight and non-line-of-sight scenarios.

Abstract

Acoustic signal acts as an essential input to many systems. However, the pure acoustic signal is very difficult to extract, especially in noisy environments. Existing beamforming systems are able to extract the signal transmitted from certain directions. However, since microphones are centrally deployed, these systems have limited coverage and low spatial resolution. We overcome the above limitations and present ChordMics, a distributed beamforming system. By leveraging the spatial diversity of the distributed microphones, ChordMics is able to extract the acoustic signal from arbitrary points. To realize such a system, we further address the fundamental challenge in distributed beamforming: aligning the signals captured by distributed and unsynchronized microphones. We implement ChordMics and evaluate its performance under both LOS and NLOS scenarios. The evaluation results tell that ChordMics can deliver higher SINR than the centralized microphone array. The average performance gain is up to 15dB.