Study of Generalized Cross Correlation Techniques for Direction Finding of Wideband Signals

For past many years, Time delay estimation (TDE) has been a booming area of interest for research due to its widespread applications in many fields such as ultrasonic, radar, seismology, identifying, detecting and finding the location of radiating sources, sonar systems and other communication fields. Finding time difference of arrival (TDOA) between the signals received at an array of antennas is done basically in time delay estimation. Usually, the peak of cross-correlation gives the value of time delay. A generalized cross-correlation (GCC) is a well-known technique for time delay estimation. In this paper, generalized cross-correlation is used for time delay estimation between the signals. This technique utilizes various windowing functions to improve the delay estimation by narrowing the main lobe and reducing the side lobes in cross-correlation function. These window functions use a specific characteristic of signals itself and embedded noise. Typically, GCC is applied to narrow band systems such as radar, sonar etc. This paper proposes an analysis of GCC techniques for direction finding in wideband signals and compute root mean square error (RMSE) for the delay estimates obtained over the range of SNRs. Analysis, simulation and results are obtained by using MATLAB.