Blind synchronization in wireless sensor networks with application to speech enhancement
Dani Cherkassky, Sharon Gannot · 2014
The sampling rate offset (SRO) phenomenon in wireless acoustic sensor network (WASN) is considered in this work. The use of different clock sources in each node results in a drift between the nodes' signals. The aim of this work is to estimate these SROs and to re-synchronize the network, enabling coherent multi-microphone processing. First, the link between SRO and the Doppler effect is driven. Then, a wideband correlation processor for SRO estimation, which is equivalent to continuous wavelet transform (CWT), is proposed. Finally, the node synchronization is achieved by re-sampling the signals at each node. Experimental study using an actual WASN, demonstrates the ability of the proposed algorithm to re-synchronize the network and to regain the performance loss due to SRO.