Semantic Satellite Communications for Synchronized Audiovisual Reconstruction

TL;DR

This paper introduces an adaptive semantic transmission system for satellite communications that dynamically switches between audio and video modalities, reducing bandwidth use while maintaining synchronized audiovisual quality.

Contribution

The paper presents a novel dual-stream generative architecture with dynamic keyframe updates and a language model-based decision module for improved satellite audiovisual transmission.

Findings

Significantly reduces bandwidth consumption

Achieves high-fidelity audiovisual synchronization

Enhances robustness in challenging satellite conditions

Abstract

Satellite communications face severe bottlenecks in supporting high-fidelity synchronized audiovisual services, as conventional schemes struggle with cross-modal coherence under fluctuating channel conditions, limited bandwidth, and long propagation delays. To address these limitations, this paper proposes an adaptive multimodal semantic transmission system tailored for satellite scenarios, aiming for high-quality synchronized audiovisual reconstruction under bandwidth constraints. Unlike static schemes with fixed modal priorities, our framework features a dual-stream generative architecture that flexibly switches between video-driven audio generation and audio-driven video generation. This allows the system to dynamically decouple semantics, transmitting only the most important modality while employing cross-modal generation to recover the other. To balance reconstruction quality and transmission overhead, a dynamic keyframe update mechanism adaptively maintains the shared knowledge base according to wireless scenarios and user requirements. Furthermore, a large language model based decision module is introduced to enhance system adaptability. By integrating satellite-specific knowledge, this module jointly considers task requirements and channel factors such as weather-induced fading to proactively adjust transmission paths and generation workflows. Simulation results demonstrate that the proposed system significantly reduces bandwidth consumption while achieving high-fidelity audiovisual synchronization, improving transmission efficiency and robustness in challenging satellite scenarios.