Array-Level Approach to Nonlinear Equalization

Abstract

Low-cost digital arrays suffer from nonlinear distortion, in both the transmitters (Tx) and receivers (Rx), introducing nonlinear spurious products, compression, and memory effects. Many linearization techniques have been researched to mitigate nonlinear distortion, such as digital pre-distortion (DPD) for Tx and nonlinear equalization (NLEQ) for Rx. However, these linearization techniques have mostly focused on channel-level correction, ignoring the array-level aspects. This paper gives an overview of the array-level aspects that need to be taken into account to effectively use NLEQ for digital arrays. Furthermore, an averaging method is proposed to help reduce computational complexity of NLEQ techniques, while leveraging the previously discussed array-level advantages.