Scattering iterative method based on generalized wave variables for the implementation of audio circuits with multiple one-port nonlinearities

The Scattering Iterative Method (SIM) is a recently developed fixed-point method relying on Wave Digital (WD) principles for the discrete-time simulation of electrical networks containing multiple one-port nonlinearities. Due to its robustness and efficiency, SIM proved itself to be suitable for the digital emulation of nonlinear audio circuits in Virtual Analog applications. The existent SIM formalization uses voltage wave variables. In this paper, we extend such a formalization to accommodate circuit descriptions based on generalized wave variables, including voltage, current, and power-normalized waves, as particular cases. A SIM-based WD implementation of a passive audio compressor employing the newly introduced generalized wave framework is presented, along with an analysis of the SIM convergence speed considering different types of waves and two different initialization strategies.