Classical and Quantum Processing in the Deep Physical Layer

The objective of this paper is to examine the processing of the electromagnetic field in the physical communication channel of wireless systems using the concept of the 'Deep Physical Layer' (DPL), a layer that is positioned below the Physical Layer of the OSI model. The article delves into the fundamental concept of DPL and presents several numerical findings on devices that can process the field directly in the DPL. These devices are called Electromagnetic field Processing Devices (EPDs) and consist of reflective elements that are extensively distributed in space. They can intelligently modify the spatial configuration of the electromagnetic field to achieve efficient processing. The study reveals that EPDs offer the potential to encode a massive amount of information in the spatial domain. Additionally, the results suggest that quantum computers are an indispensable technology to gain unrestricted access to the large resources that utilizing EPDs in the DPL can unlock. To fully utilize this vast resource necessitates addressing the challenge of searching an unstructured database, which poses a difficulty for classical computers. However, this problem can be efficiently solved by quantum computers using Grover's algorithm.