The diagnosis and treatment of cardiac arrhythmias relies on catheter recordings, that may be inefficient because of the continued use of the bipolar processing and analysis techniques of traditional catheters, missing the potential of the novel matrix catheters. This results in the need of more processing of the signals and longer cardiac scans to obtain accurate information about the state of the tissue being analysed. This study proposes a new clique configuration to compute omnipolar EGM (oEGM) in multielectrode array catheters to obtain parameters of interest in a more robust and accurate manner. Numerous simulations with varying input parameters are designed to emulate the propagation of electrical activity on the cardiac tissue surface captured by the catheter and characterise the differences between the classic method of omnipolar analysis (triangular clique) and our proposed new method (cross clique). The results show that the cross clique is more robust to variations in the direction of wave propagation, and more accurate in the estimation of the local activation time (LAT).