Stochastic Packet Reconstruction for Subjectively Improved Audio Delivery over WLANs

Abstract

Real time digital audio delivery over Wireless Local Area Networks (WLANs) represents an attractive, flexible and cost effective framework for realizing high-quality, multichannel home audio applications. However, the unreliable nature of WLANs IP link frequently imposes significant playback quality degradation, due to delay or permanent loss of a number of transmitted digital audio packets. In this paper, a novel packet error concealment technique is presented, based on the spectral reconstruction of the statistical equivalent of a previously successfully received audio data packet. It is shown that the proposed data reconstruction scheme outperforms previously published error concealment strategies, in both terms of objective and perceptual criteria.

WLAN Technologies for Audio Delivery

“…An application-level mechanism such as the proposed CoDeS synchronization algorithm will generally ensure that the reproduction is kept synchronized for WLAN transmission-induced errors by keeping the delay for each traffic stream constant, for each serviced device. Additionally, although it is out of the scope of this work, it is expected that the CoDeS synchronization algorithm combined with a packet concealment method [32,33] will minimize the perceptual effect of the distortions that are introduced by the insertion of silence gaps and proportionally increase the achieved playback quality. Furthermore, by increasing the available bandwidth, the effect of the channel interference on the final playback quality can be reduced.…”