Echo decomposition based time delay sensor with sub-sample resolution

Time-delay estimation (TDE) sensors can be used to effectively locate a transmitting source. Our aim is to use distributed TDE sensors that are relatively inexpensive. The latter is the result of two constraints: a single analog to digital converter is used for sampling the sum of two sensor output signals, and the sampling interval is substantially larger than the practically required time delay resolution. This approach leads to the requirement for sub-sample interval delay estimation from overlapping different echoes of a received signal. No specific a priori assumptions are made regarding the nature of the received signal. We adapt the time-frequency ratio of mixtures (TFRM) approach for blind source separation for our TDE sensor. Our experimental set-up consists of two microphones placed at non-equal distances from an acoustic source. The TDEs are then used for source localization.