Robust Image Semantic Coding with Learnable CSI Fusion Masking over MIMO Fading Channels

TL;DR

This paper introduces a novel semantic communication framework that leverages learnable CSI fusion masking within a Swin Transformer architecture to improve robustness over MIMO fading channels, addressing a gap in practical system applications.

Contribution

It proposes the LCFSC framework that incorporates MIMO CSI as side information with a non-invasive attention module and learnable masking, enhancing semantic coding robustness in MIMO channels.

Findings

Outperforms traditional schemes in MIMO fading channels.

Demonstrates improved robustness with learnable CSI fusion masking.

Achieves superior semantic communication performance over state-of-the-art methods.

Abstract

Though achieving marvelous progress in various scenarios, existing semantic communication frameworks mainly consider single-input single-output Gaussian channels or Rayleigh fading channels, neglecting the widely-used multiple-input multiple-output (MIMO) channels, which hinders the application into practical systems. One common solution to combat MIMO fading is to utilize feedback MIMO channel state information (CSI). In this paper, we incorporate MIMO CSI into system designs from a new perspective and propose the learnable CSI fusion semantic communication (LCFSC) framework, where CSI is treated as side information by the semantic extractor to enhance the semantic coding. To avoid feature fusion due to abrupt combination of CSI with features, we present a non-invasive CSI fusion multi-head attention module inside the Swin Transformer. With the learned attention masking map determined by both source and channel states, more robust attention distribution could be generated. Furthermore, the percentage of mask elements could be flexibly adjusted by the learnable mask ratio, which is produced based on the conditional variational interference in an unsupervised manner. In this way, CSI-aware semantic coding is achieved through learnable CSI fusion masking. Experiment results testify the superiority of LCFSC over traditional schemes and state-of-the-art Swin Transformer-based semantic communication frameworks in MIMO fading channels.