Study on the pre-processors to improve the generalized-cross -correlation based time delay estimation under the narrow band single tone signal environments

There are several methods for the time delay estimation between signals to two receivers. Among these methods, Generalized Cross Correlation (GCC), which estimates the relative delay from the crosscorrelation between the different signals at the two receivers, is a traditionally well-known method. However, when using a narrow band Continuous Wave (CW) signal, the GCC method degrades the estimation performance from relatively higher signal-to-noise ratio than when using a wideband signal. To improve this phenomenon, this paper examines four different pre-processors for GCC using narrow band single frequency signals. Simulation shows that the performance gain of the preprocessed GCC is up to 9 dB for a 100 msec CW signal as well as up to 4 dB for a 1 s CW signal.