6G physical layer technologies in telecommunication networks

Abstract

The article explores the conceptual foundations and technical solutions aimed at designing Next-Generation Air Interfaces (NGAI) capable of meeting the target performance indicators of sixth-generation (6G) networks. These targets include enhanced spectral efficiency, ultra-low latency, scalability, energy efficiency, cybersecurity, resilience to dynamic transmission environments, and the integration of intelligent control functions. The evolution of access technologies up to 5G is analyzed, identifying key architectural, functional, and protocol-level limitations that hinder the full realization of 6G requirements. The study summarizes the main development directions for NGAI, including the implementation of cognitive radio with intelligent spectrum analysis, non-orthogonal multiple access (NOMA), rate-splitting multiple access (RSMA), massive MIMO with narrow-beamforming, terahertz-band communication, and the use of reconfigurable intelligent surfaces (RIS) for adaptive channel control. The role of machine learning (ML) and deep learning (DL) algorithms in these areas is emphasized. Special attention is given to the influence of AI/ML on dynamic radio resource management functions such as spectral environment adaptation, traffic load prediction, self-optimization, and real-time cognitive decision-making. The article examines innovative modulation and coding schemes, including geometric QAM, LDPC codes, Polar codes, compressive sensing, and orbital angular momentum (OAM)-based multiplexing. An architectural model of an integrated air interface is proposed, supporting Fog/Edge/Mist/Cloud computing infrastructures, XR services, the Internet of Everything (IoE), autonomous systems, and mobile agents. The potential of Cell-Free Massive MIMO and non-terrestrial network (NTN) components is explored within the 6G-SAGIN (Space–Air–Ground Integrated Network) architecture. Systemic approaches to implementing energy-efficient, adaptive, secure, and intelligent NGAI are substantiated, positioning it as a key enabler of the 6G infocommunication ecosystem, capable of merging physical, digital, and cyber spaces into a unified functional platform of the future.