“…Further, GSF provides a feasible approach to meet both accuracy and real time required in the filtering problem of nonlinear time-delay systems. However, the existing literatures concerning GSF or GF have been limited to the research on the robust filter for dealing with the model error [13], on the adaptive filter with Gaussian sum refinement and coarsening [12,14], on the numerical technologies for approximating the nonlinear integrals [15][16][17][18][19][20], on the state smoothing framework design [10,[21][22][23], on the numerical and stability analyses [24][25][26][27][28], on the constrained estimation [29][30][31], and on the colored and correlated noises [9,10]. So far, there are seldom results paying adequate research attention on designing the GSF for the nonlinear time-delay systems despite GSF has been significantly shown to be good at both accuracy and real time.…”