Abstract-Complex-valued (CV) B-spline neural network approach offers a highly effective means for identifying and inverting practical Hammerstein systems. Compared to its conventional CV polynomial based counterpart, CV B-spline neural network has superior performance in identifying and inverting CV Hammerstein systems, while imposing a similar complexity. This paper reviews the optimality of CV B-spline neural network approach. Advantages of B-spline neural network approach as compared to polynomial based modeling approach are extensively discussed, and the effectiveness of CV neural network based approach is demonstrated in a real-world application. More specifically, we evaluate the comparative performance of the CV B-spline and polynomial based approaches for the nonlinear iterative frequency-domain decision feedback equalization (NIFDDFE) of single-carrier Hammerstein channels. Our results confirm the superior performance of the CV B-spline based NIFDDFE over its CV polynomial based counterpart.Index Terms-Complex-valued (CV) B-spline neural network, CV polynomial model, identification and inversion of Hammerstein channels, nonlinear iterative frequency-domain decision feedback equalization I. INTRODUCTION In many real-world applications, the underlying system that generates complex-valued (CV) signals can be modeled by the CV Hammerstein model. The system is grey-box, as its structure is known to be consisting of an unknown static nonlinearity followed by an unknown linear dynamic model. A well-known example of CV Hammerstein systems is the single-carrier (SC) block transmission communication channel with nonlinear high power amplifier (HPA) at transmitter, whereby the CV static nonlinearity of the Hammerstein system is constituted by the nonlinear transmit HPA, and its linear dynamic subsystem is the dispersive channel which can usually be modeled as a finite-duration impulse response (FIR) filter. Effective identification and inversion of CV Hammerstein systems is therefore crucial in these practical applications.CV B-spline neural network has widely been used as an effective means for identification and inversion of CV