Multimedia Semantic Communications: Representation, Encoding and Transmission

The sixth generation (6G) mobile communication systems could serve new multimodal services, such as virtual reality (VR), augmented reality (AR), holographic projection. These new services are accompanied by new demands for intelligence, personalization and collaboration. Semantic communications are increasingly attracting attention due to its potential to support the aforementioned multimodal services. Therefore, in this article, we discuss key technologies for semantic communications, which involve semantic representation, semantic encoding and decoding, and transmission of semantic information. First, we present existing work on semantic communications, such as sketch graph structure representation of images, semantic reconstruction, and end-to-end semantic communication systems. Second, we identify challenges in semantic communication systems and propose the unified semantic representations, semantic codecs, and multiple access techniques for support the semantic information transmission. Last, we present the results of semantic encoding and decoding methods and the coexistence of semantics and bits transmission supported by the non-orthogonal multiple access technique (NOMA).

Automated summary

This article discusses key technologies for semantic communications, including semantic representation, semantic encoding and decoding, and transmission of semantic information. Existing work on semantic communications is presented, such as sketch graph structure representation of images, semantic reconstruction, and end-to-end semantic communication systems. Challenges in semantic communication systems are identified, and unified semantic representations, semantic codecs, and multiple access techniques are proposed to support the transmission of semantic information. The results of semantic encoding and decoding methods and the coexistence of semantics and bits transmission supported by the non-orthogonal multiple access technique (NOMA) are presented.