This paper deals with the behavioral modeling of nonlinear systems. In particular, the modeling of near-carrier inter-modulation (IMD) distorsion in baseband, i.e. on complex signals, after I/Q demodulation. A reduction and a simplification of the Volterra BaseBand Series model (VBBS) are thus proposed. The proposed models are then compared to the literature according to several criteria, the computational complexity, and the accuracy of the modeling on the variation in frequency of the distortion. Simulations carried-out show a good trade-off between computational complexity and lineariza- tion performance for low memory depths, when compared to literature models.