SAFE: Semantic Adaptive Feature Extraction with Rate Control for 6G Wireless Communications
Yuna Yan, Lixin Li, Xin Zhang, Wensheng Lin, Wenchi Cheng, Zhu Han
TL;DR
SAFE tackles the rigidity of fixed-rate semantic communication by introducing a semantic adaptive feature extraction framework that decomposes images into multiple sub-semantics and enables adaptive transmission across channel bandwidths. It employs a U-Net–inspired architecture with two sub-semantics and a semantic contraction decoder to reconstruct images as more information is received, while defining bandwidth ratios $k_i/n$ and $k/n$ to quantify capacity usage. The authors propose three training strategies to efficiently train the SAFE network and demonstrate, on ImageNet100, that adaptive use of sub-semantics yields improved bandwidth efficiency and robustness across AWGN and Rayleigh channels. This work advances practical, bandwidth-aware semantic communication for 6G by enabling flexible, task-agnostic image transmission with progressive quality refinement.
Abstract
Most current Deep Learning-based Semantic Communication (DeepSC) systems are designed and trained exclusively for particular single-channel conditions, which restricts their adaptability and overall bandwidth utilization. To address this, we propose an innovative Semantic Adaptive Feature Extraction (SAFE) framework, which significantly improves bandwidth efficiency by allowing users to select different sub-semantic combinations based on their channel conditions. This paper also introduces three advanced learning algorithms to optimize the performance of SAFE framework as a whole. Through a series of simulation experiments, we demonstrate that the SAFE framework can effectively and adaptively extract and transmit semantics under different channel bandwidth conditions, of which effectiveness is verified through objective and subjective quality evaluations.
