General clipping modeling and DSP-based mitigation for wideband A/D interface and RF front-end of emerging radio receivers

Abstract

Emerging wireless communications concepts, such as cognitive radio, bring various challenges in the implementation of radio receivers. One of the concerns is the dynamic range of the receiver front-end, which might be insufficient in certain situations, e.g., if strong blocker signals are present concurrently with weaker interesting signals. Overdrive of the receiver front-end causes signal clipping and therefore considerable amount of nonlinear distortion is created. This paper derives a general parametric clipping model using time-dependent Fourier series and analyses the model in different clipping scenarios. The paper also proposes a method to exploit the derived model in a radio receiver for digital post-processing in order to mitigate unwanted clipping distortion.