# Nonlinear EM-based Signal Processing

arXiv: https://arxiv.org/abs/2512.04595 · HTML: https://mlsanity.com/paper/2512.04595/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 4 Dec 2025.

## Built on by (most cited first, 2 of 2)

- [Over-The-Air Extreme Learning Machines with XL Reception via Nonlinear Cascaded Metasurfaces](https://mlsanity.com/paper/2601.17749/) (2026)
- [Over-The-Air Extreme Learning Machines with Nonlinear Stacked Intelligent Metasurfaces](https://mlsanity.com/paper/2608.27137/) (2026)

## Abstract (arXiv)

The use of high-frequency bands, combined with antenna arrays containing an extremely large number of elements (XL-MIMO), is pushing current technology to its limits in terms of hardware complexity, latency, and power consumption. A promising approach to achieving scalable and sustainable solutions is to shift part of the signal processing directly into the electromagnetic (EM) domain. In this paper, we investigate novel architectures that harness the interaction of reconfigurable passive linear and nonlinear (NL) scattering elements positioned in the reactive near field of signal sources. The objective is to enable multifunctional linear and NL EM signal processing to occur directly "over-the-air." Numerical results highlight the potential to significantly reduce both system complexity and the number of RF chains, while still achieving key performance metrics in applications such as direction-of-arrival and position estimation, without the need for additional analog or digital processing.