Communication-Efficient Framework for Distributed Image Semantic Wireless Transmission

Multinode communication, which refers to the interaction among multiple devices, has attracted lots of attention in many Internet of Things (IoT) scenarios. However, its huge amounts of data flows and inflexibility for task extension have triggered the urgent requirement of communication-efficient distributed data transmission frameworks. In this article, inspired by the great superiorities on bandwidth reduction and task adaptation of semantic communications, we propose a federated learning (FL)-based semantic communication (FLSC) framework for multitask distributed image transmission with IoT devices. FL enables the design of independent semantic communication link of each user while further improves the semantic extraction and task performance through global aggregation. Each link in FLSC is composed of a hierarchical vision transformer (HVT)-based extractor and a task-adaptive translator for coarse-to-fine semantic extraction and meaning translation according to specific tasks. In order to extend the FLSC into more realistic conditions, we design a channel state information-based multiple-input–multiple-output transmission module to combat channel fading and noise. Simulation results show that the coarse semantic information can deal with a range of image-level tasks. Moreover, especially in low signal-to-noise ratio (SNR) and channel bandwidth ratio regimes, FLSC evidently outperforms the traditional scheme, e.g., about 10 peak SNR gain in the 3-dB channel condition.