Bridging Neural Networks and Wireless Systems with MIMO-OFDM Semantic Communications

Semantic communications aim to enhance transmission efficiency by jointly optimizing source coding, channel coding, and modulation. While prior research has demonstrated promising performance in simulations, real-world implementations often face significant challenges, including noise variability and nonlinear distortions, leading to performance gaps. This article investigates these challenges in a multiple-input multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM)-based semantic communication system, focusing on the practical impacts of power amplifier (PA) nonlinearity and peak-to-average power ratio (PAPR) variations. Our analysis identifies frequency selectivity of the actual channel as a critical factor in performance degradation and demonstrates that targeted mitigation strategies can enable semantic systems to approach theoretical performance. By addressing key limitations in existing designs, we provide actionable insights for advancing semantic communications in practical wireless environments. This work establishes a foundation for bridging the gap between theoretical models and real-world deployment, highlighting essential considerations for system design and optimization.

A State-of-the-art Survey on Full-duplex Network Design

Full-duplex (FD) technology is gaining popularity for integration into a wide range of wireless networks due to its demonstrated potential in recent studies. In contrast to half-duplex (HD) technology, the implementation of FD in networks necessitates considering inter-node interference (INI) from various network perspectives. When deploying FD technology in networks, several critical factors must be taken into account. These include self-interference (SI) and the requisite SI cancellation (SIC) processes, as well as the selection of multiple user equipment (UE) per time slot. Additionally, inter-node interference (INI), including cross-link interference (CLI) and inter-cell interference (ICI), become crucial issues during concurrent uplink (UL) and downlink (DL) transmission and reception, similar to SI. Since most INI is challenging to eliminate, a comprehensive investigation that covers radio resource control (RRC), medium access control (MAC), and the physical layer (PHY) is essential in the context of FD network design, rather than focusing on individual network layers and types. This paper covers state-of-the-art studies, including protocols and documents from 3GPP for FD, MAC protocol, user scheduling, and CLI handling. The methods are also compared through a network-level system simulation based on 3D ray-tracing.