Attention-based UNet enabled Lightweight Image Semantic Communication System over Internet of Things

TL;DR

This paper introduces a lightweight, attention-based UNet system for semantic image communication in IoT devices, reducing computational load and model size while maintaining high accuracy, suitable for efficient video service applications.

Contribution

It proposes an attention-enhanced UNet architecture trained at edge servers, significantly reducing complexity and size for IoT deployment compared to existing methods.

Findings

FLOPs reduced by 14%

Model size decreased by 55%

Achieves higher accuracy in low SNR conditions

Abstract

This paper studies the problem of the lightweight image semantic communication system that is deployed on Internet of Things (IoT) devices. In the considered system model, devices must use semantic communication techniques to support user behavior recognition in ultimate video service with high data transmission efficiency. However, it is computationally expensive for IoT devices to deploy semantic codecs due to the complex calculation processes of deep learning (DL) based codec training and inference. To make it affordable for IoT devices to deploy semantic communication systems, we propose an attention-based UNet enabled lightweight image semantic communication (LSSC) system, which achieves low computational complexity and small model size. In particular, we first let the LSSC system train the codec at the edge server to reduce the training computation load on IoT devices. Then, we introduce the convolutional block attention module (CBAM) to extract the image semantic features and decrease the number of downsampling layers thus reducing the floating-point operations (FLOPs). Finally, we experimentally adjust the structure of the codec and find out the optimal number of downsampling layers. Simulation results show that the proposed LSSC system can reduce the semantic codec FLOPs by 14%, and reduce the model size by 55%, with a sacrifice of 3% accuracy, compared to the baseline. Moreover, the proposed scheme can achieve a higher transmission accuracy than the traditional communication scheme in the low channel signal-to-noise (SNR) region.