Performance Limits in Subband Beamforming

Document type: Journal Articles
Article type: Original article
Peer reviewed: Yes
Full text:
Author(s): Sven Nordholm, Ingvar Claesson, Nedelko Grbic
Title: Performance Limits in Subband Beamforming
Translated title: Prestandagränser i delbandsbeamforming
Journal: IEEE Transactions on Speech and Audio Processing
Year: 2003
Volume: 11
Issue: 3
Pagination: 193-203
ISSN: 1063-6676
Publisher: IEEE
ISI number: 000183877300004
Organization: Blekinge Institute of Technology
Department: Dept. of Signal Processing (Institutionen för signalbehandling)
Dept. of Signal Processing S-372 25 Ronneby
+46 455 38 50 00
Language: English
Abstract: This paper analyzes subband beamforming schemes mainly aimed at speech enhancement and acoustic echo suppression applications such as hands-free telephony for both mobile and office environments, internet telephony and video conferencing. Analytical descriptions of both causal finite-length and noncausal infinite-length subband microphone array structures are given. More specifically, this paper compares finite Wiener filter performance with the noncausal Wiener solution, giving a comprehensive theoretical suppression limit. It is shown that even short filters will yield a good approximation of the infinite solution, provided that the element spacing and temporal sampling is matched to the frequency band of interest. Typically, 10-20 FIR taps are sufficient in each subband.
Subject: Signal Processing\Beamforming
Signal Processing\Speech Enhancement
Keywords: beamforming, speech enhancement, filterbank, subband, hands-free, microphone array