Simplifying Antiderivative Antialiasing with Lookup Table Integration
Antiderivative Antialiasing (ADAA), has become a pivotal method
for reducing aliasing when dealing with nonlinear function at audio rate. However, its implementation requires analytical computation of the antiderivative of the nonlinear function, which in practical cases can be challenging without a symbolic solver. Moreover, when the nonlinear function is given by measurements it
must be approximated to get a symbolic description. In this paper, we propose a simple approach to ADAA for practical applications that employs numerical integration of lookup tables (LUTs)
to approximate the antiderivative. This method eliminates the need
for closed-form solutions, streamlining the ADAA implementation
process in industrial applications. We analyze the trade-offs of this
approach, highlighting its computational efficiency and ease of implementation while discussing the potential impact of numerical
integration errors on aliasing performance. Experiments are conducted with static nonlinearities (tanh, a simple wavefolder and
the Buchla 259 wavefolding circuit) and a stateful nonlinear system (the diode clipper).